Diffraction - Revision history

https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?action=history&feed=atom&title=Diffraction Diffraction - Revision history 2026-05-02T21:36:02Z Revision history for this page on the wiki MediaWiki 1.41.1 https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=3782&oldid=prev Lwcamp at 18:59, 7 March 2026 2026-03-07T18:59:54Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:59, 7 March 2026</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l104">Line 104:</td> <td colspan="2" class="diff-lineno">Line 104:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==References==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==References==</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Lasers]][[Category:Physics & Engineering]]</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Lasers]][[Category:Physics <ins style="font-weight: bold; text-decoration: none;">& Engineering]][[Category:Physics & Math </ins>& Engineering]]</div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=3142&oldid=prev Lwcamp at 22:16, 8 April 2025 2025-04-08T22:16:06Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:16, 8 April 2025</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l53">Line 53:</td> <td colspan="2" class="diff-lineno">Line 53:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>If we have two identical apertures and shine them at the same spot, we get some interference fringes. With the apertures nearly touching, as in this picture, the interference fringes are fairly broad. We get only one interference fringe in our illuminated spot and the illuminated area is essentially cut in half. We start getting hints of the neat things we can do when we note that if we shift the relative phases of the two apertures, we can control where the horizontal bar of the interference fringe occurs. In the picture below, the center image shows the interference pattern with no phase shift and the right-most picture how the fringe shifts if the relative phase between the two apertures is adjusted to about <del style="font-weight: bold; text-decoration: none;"><math>\pi</del>/2<del style="font-weight: bold; text-decoration: none;"></math> </del>radians.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>If we have two identical apertures and shine them at the same spot, we get some interference fringes. With the apertures nearly touching, as in this picture, the interference fringes are fairly broad. We get only one interference fringe in our illuminated spot and the illuminated area is essentially cut in half. We start getting hints of the neat things we can do when we note that if we shift the relative phases of the two apertures, we can control where the horizontal bar of the interference fringe occurs. In the picture below, the center image shows the interference pattern with no phase shift and the right-most picture how the fringe shifts if the relative phase between the two apertures is adjusted to about <ins style="font-weight: bold; text-decoration: none;">π</ins>/2 radians.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table class="center" style="width: auto; margin-left: auto; margin-right: auto;"></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table class="center" style="width: auto; margin-left: auto; margin-right: auto;"></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><tr></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><tr></div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=3141&oldid=prev Lwcamp: /* Beam Shape */ 2025-04-08T22:15:21Z

<p><span dir="auto"><span class="autocomment">Beam Shape</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:15, 8 April 2025</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l25">Line 25:</td> <td colspan="2" class="diff-lineno">Line 25:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Beam Shape==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Beam Shape==</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>A focused, diffraction limited beam can be approximated as converging on a focal point at range at <del style="font-weight: bold; text-decoration: none;"><math></del>R<del style="font-weight: bold; text-decoration: none;"></math> </del>with a beam width</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>A focused, diffraction limited beam can be approximated as converging on a focal point at range at R with a beam width</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;"<del style="font-weight: bold; text-decoration: none;">><math</del>>W = <del style="font-weight: bold; text-decoration: none;">\left| </del>D <del style="font-weight: bold; text-decoration: none;">\, \left</del>(1 - <del style="font-weight: bold; text-decoration: none;">\frac{</del>x<del style="font-weight: bold; text-decoration: none;">}{</del>R<del style="font-weight: bold; text-decoration: none;">} \right</del>) <del style="font-weight: bold; text-decoration: none;">\right|</math></del></div></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;">W = <ins style="font-weight: bold; text-decoration: none;">&vert; </ins>D (1 - x <ins style="font-weight: bold; text-decoration: none;">/ </ins>R) <ins style="font-weight: bold; text-decoration: none;">&vert;</ins></div></div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>at any given distance <del style="font-weight: bold; text-decoration: none;"><math></del>x<del style="font-weight: bold; text-decoration: none;"></math> </del>along the beam as long as <del style="font-weight: bold; text-decoration: none;"><math></del>W > S<del style="font-weight: bold; text-decoration: none;"></math></del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>at any given distance x along the beam as long as W > S.</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Once <del style="font-weight: bold; text-decoration: none;"><math></del>W < S<del style="font-weight: bold; text-decoration: none;"></math></del>, the beam will propagate in a nearly collimated line for a distance</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Once W < S, the beam will propagate in a nearly collimated line for a distance</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;"<del style="font-weight: bold; text-decoration: none;">><math</del>>Z = <del style="font-weight: bold; text-decoration: none;">\frac{</del>2 <del style="font-weight: bold; text-decoration: none;">\, </del>S <del style="font-weight: bold; text-decoration: none;">\, </del>R<del style="font-weight: bold; text-decoration: none;">}{</del>D<del style="font-weight: bold; text-decoration: none;">} </del>= <del style="font-weight: bold; text-decoration: none;">\frac{</del>2 <del style="font-weight: bold; text-decoration: none;">\, </del>S<del style="font-weight: bold; text-decoration: none;">^</del>2<del style="font-weight: bold; text-decoration: none;">}{</del>1.22 <del style="font-weight: bold; text-decoration: none;">\, \lambda}</math></del></div></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;">Z = 2 S R <ins style="font-weight: bold; text-decoration: none;">/ </ins>D = 2 S<ins style="font-weight: bold; text-decoration: none;"><sup></ins>2<ins style="font-weight: bold; text-decoration: none;"></sup> / (</ins>1.22 <ins style="font-weight: bold; text-decoration: none;">λ)</ins></div></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Diffraction limited beam approximation near focus.png|640 px|The actual beam profile (red) and the approximate profile (blue).]]</div></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[File:Diffraction limited beam approximation near focus.png|640 px|The actual beam profile (red) and the approximate profile (blue).]]</div></div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In practice, you will probably want to focus a distance <del style="font-weight: bold; text-decoration: none;"><math></del>Z/2<del style="font-weight: bold; text-decoration: none;"></math> </del>behind your target, in order to get the beam going straight for as long as possible once it encounters the target. When you take pictures, <del style="font-weight: bold; text-decoration: none;"><math></del>Z<del style="font-weight: bold; text-decoration: none;"></math> </del>is called the depth of field, reflecting the limitations on the camera’s ability to focus at all distances. Likewise, we will refer to this distance for laser weapons as depth of focus for the same reason.<ref name="MellesGriot">[http://www.pa.msu.edu/courses/2010fall/phy431/PostNotes/PHY431-Notes-GaussianBeamOptics.pdf Melles Griot. Gaussian Beam Optics]</ref> (Note that in the literature, the region where the beam is nearly parallel is the <i>beam waist</i>, our spot size <del style="font-weight: bold; text-decoration: none;"><math></del>S<del style="font-weight: bold; text-decoration: none;"></math> </del>is closely related to the <i>waist radius</i> <<del style="font-weight: bold; text-decoration: none;">math</del>><del style="font-weight: bold; text-decoration: none;">\omega_0</del></<del style="font-weight: bold; text-decoration: none;">math</del>> and our depth of focus is closely related to the <i>Rayleigh range</i> <<del style="font-weight: bold; text-decoration: none;">math</del>><del style="font-weight: bold; text-decoration: none;">z_R</del></<del style="font-weight: bold; text-decoration: none;">math</del>>.)</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In practice, you will probably want to focus a distance Z/2 behind your target, in order to get the beam going straight for as long as possible once it encounters the target. When you take pictures, Z is called the depth of field, reflecting the limitations on the camera’s ability to focus at all distances. Likewise, we will refer to this distance for laser weapons as depth of focus for the same reason.<ref name="MellesGriot">[http://www.pa.msu.edu/courses/2010fall/phy431/PostNotes/PHY431-Notes-GaussianBeamOptics.pdf Melles Griot. Gaussian Beam Optics]</ref> (Note that in the literature, the region where the beam is nearly parallel is the <i>beam waist</i>, our spot size S is closely related to the <i>waist radius</i> <ins style="font-weight: bold; text-decoration: none;">ω</ins><<ins style="font-weight: bold; text-decoration: none;">sub</ins>><ins style="font-weight: bold; text-decoration: none;">0</ins></<ins style="font-weight: bold; text-decoration: none;">sub</ins>> and our depth of focus is closely related to the <i>Rayleigh range</i> <ins style="font-weight: bold; text-decoration: none;">z</ins><<ins style="font-weight: bold; text-decoration: none;">sub</ins>><ins style="font-weight: bold; text-decoration: none;">R</ins></<ins style="font-weight: bold; text-decoration: none;">sub</ins>>.)</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Beam Quality==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Beam Quality==</div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=3140&oldid=prev Lwcamp: /* Spot Size */ 2025-04-08T22:09:41Z

<p><span dir="auto"><span class="autocomment">Spot Size</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:09, 8 April 2025</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l16">Line 16:</td> <td colspan="2" class="diff-lineno">Line 16:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Spot Size==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Spot Size==</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>For a laser, we want to shine our beam on something. But as soon as the laser gets out of the machine that is making it and guiding it, it diffracts around the aperture that emits the beam into the wider world. This diffraction limits the amount by which the laser can be focused, or even by which it can move straight. This means that if you try to focus the beam down to a tiny point at a distant target, the beam might spread out to a much larger spot by the time it gets there. The amount the beam expands depends on the ratio of the initial width of the beam to the wavelength of the beam. In fact, we can determine the smallest possible spot size into which you can focus the beam: if we denote the diameter of the mirror, lens, or other opening in the laser or focusing element as <del style="font-weight: bold; text-decoration: none;"><math></del>D<del style="font-weight: bold; text-decoration: none;"></math></del>, the wavelength of the light as <del style="font-weight: bold; text-decoration: none;"><math>\lambda</math></del>, and the distance to the target as <del style="font-weight: bold; text-decoration: none;"><math></del>R<del style="font-weight: bold; text-decoration: none;"></math></del>, then the diameter of the smallest spot, <del style="font-weight: bold; text-decoration: none;"><math></del>S<del style="font-weight: bold; text-decoration: none;"></math></del>, is given by<ref name="Giancoli">Douglas C. Giancoli, “Physics for Scientists and Engineers, Second Edition”, Prentice Hall, Englewood Cliffs, New Jersey (1988)</ref></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>For a laser, we want to shine our beam on something. But as soon as the laser gets out of the machine that is making it and guiding it, it diffracts around the aperture that emits the beam into the wider world. This diffraction limits the amount by which the laser can be focused, or even by which it can move straight. This means that if you try to focus the beam down to a tiny point at a distant target, the beam might spread out to a much larger spot by the time it gets there. The amount the beam expands depends on the ratio of the initial width of the beam to the wavelength of the beam. In fact, we can determine the smallest possible spot size into which you can focus the beam: if we denote the diameter of the mirror, lens, or other opening in the laser or focusing element as D, the wavelength of the light as <ins style="font-weight: bold; text-decoration: none;">λ</ins>, and the distance to the target as R, then the diameter of the smallest spot, S, is given by<ref name="Giancoli">Douglas C. Giancoli, “Physics for Scientists and Engineers, Second Edition”, Prentice Hall, Englewood Cliffs, New Jersey (1988)</ref></div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;"<del style="font-weight: bold; text-decoration: none;">><math</del>>S = 1.22 <del style="font-weight: bold; text-decoration: none;">\, </del>R <del style="font-weight: bold; text-decoration: none;">\, \frac{\lambda}{</del>D<del style="font-weight: bold; text-decoration: none;">}</math></del>.</div></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><div class="center" style="width: auto; margin-left: auto; margin-right: auto;">S = 1.22 R <ins style="font-weight: bold; text-decoration: none;">λ / </ins>D.</div></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is called the Rayleigh critereon.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is called the Rayleigh critereon.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=2897&oldid=prev Tshhmon at 21:30, 23 April 2024 2024-04-23T21:30:38Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 14:30, 23 April 2024</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l104">Line 104:</td> <td colspan="2" class="diff-lineno">Line 104:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==References==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==References==</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Lasers]]</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Lasers<ins style="font-weight: bold; text-decoration: none;">]][[Category:Physics & Engineering</ins>]]</div></td></tr> </table>

Tshhmon https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=977&oldid=prev Lwcamp: /* Interference and Phased Arrays */ 2022-01-12T05:03:07Z

<p><span dir="auto"><span class="autocomment">Interference and Phased Arrays</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 22:03, 11 January 2022</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l79">Line 79:</td> <td colspan="2" class="diff-lineno">Line 79:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>With no relative phase shift, we see that we can do almost as well as a single large aperture (middle). But if we introduce a relative phase shifts between our tiled apertures, we can move that spot around anywhere within the spot area of a single small aperture (right). We can now rapidly electronically scan a small spot over an area without having to mechanically move our beam pointer. This is called a phased array</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>With no relative phase shift, we see that we can do almost as well as a single large aperture (middle). But if we introduce a relative phase shifts between our tiled apertures, we can move that spot around anywhere within the spot area of a single small aperture (right). We can now rapidly electronically scan a small spot over an area without having to mechanically move our beam pointer. This is called a phased array</div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><ref>Kevin D. Bell, Michael K. Powers, Steven Griffin, and Steven Huybrechts, "Air Force Research Laboratory's Technology Programs Addressing Deployable Space Optical Systems", Part of the SPIE Conference on Space Telescoes and Instruments V, Kona, Hawaii, March 1998, SPIE Vol. 3356, 0277-786X1</ref></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ref><ins style="font-weight: bold; text-decoration: none;">[https://www.spiedigitallibrary.org/conference-proceedings-of-spie/3356/0000/Air-force-research-laboratorys-technology-programs-addressing-deployable-space-optical/10.1117/12.324475.short?SSO=1 </ins>Kevin D. Bell, Michael K. Powers, Steven Griffin, and Steven Huybrechts, "Air Force Research Laboratory's Technology Programs Addressing Deployable Space Optical Systems", Part of the SPIE Conference on Space Telescoes and Instruments V, Kona, Hawaii, March 1998, SPIE Vol. 3356, 0277-786X1<ins style="font-weight: bold; text-decoration: none;">]</ins></ref></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=976&oldid=prev Lwcamp: /* Interference and Phased Arrays */ 2022-01-12T05:00:59Z

<p><span dir="auto"><span class="autocomment">Interference and Phased Arrays</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 22:00, 11 January 2022</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l78">Line 78:</td> <td colspan="2" class="diff-lineno">Line 78:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><td width=258>[[File:Laser_interference_pattern_from_tiled_hexagonal_aperture_with phase_shift.png|frameless]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><td width=258>[[File:Laser_interference_pattern_from_tiled_hexagonal_aperture_with phase_shift.png|frameless]]</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>With no relative phase shift, we see that we can do almost as well as a single large aperture (middle). But if we introduce a relative phase shifts between our tiled apertures, we can move that spot around anywhere within the spot area of a single small aperture (right). We can now rapidly electronically scan a small spot over an area without having to mechanically move our beam pointer. This is called a phased array.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>With no relative phase shift, we see that we can do almost as well as a single large aperture (middle). But if we introduce a relative phase shifts between our tiled apertures, we can move that spot around anywhere within the spot area of a single small aperture (right). We can now rapidly electronically scan a small spot over an area without having to mechanically move our beam pointer. This is called a phased array</div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"><ref>Kevin D. Bell, Michael K. Powers, Steven Griffin, and Steven Huybrechts, "Air Force Research Laboratory's Technology Programs Addressing Deployable Space Optical Systems", Part of the SPIE Conference on Space Telescoes and Instruments V, Kona, Hawaii, March 1998, SPIE Vol. 3356, 0277-786X1</ref></ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We can now see the benefit of this method. If you have small individual apertures such that each has a fairly large diffraction spot, you can now rapidly flick your beam over that area. It might allow you to, for example, immediately switch between incoming missiles when you have blasted one and want to start blasting the next one without needing to cumbersomely move your giant beam pointer (and avoid all of the vibration and extra jitter that would entail). The smaller each individual aperture is, the larger the cone your beam can scan over. If you make each aperture smaller than the wavelength of the light it is emitting, your beam can be electronically steered over an entire hemisphere. While there are practical engineering issues to getting sub-micron apertures to remain in a sufficiently regular array with active phase control for each, perhaps this is something that can be done by a sufficiently advanced civilization. And even without sub-wavelength apertures, a tiled array of apertures with phase control would still have benefits even if the electronic beam steering is in a somewhat more restricted cone.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We can now see the benefit of this method. If you have small individual apertures such that each has a fairly large diffraction spot, you can now rapidly flick your beam over that area. It might allow you to, for example, immediately switch between incoming missiles when you have blasted one and want to start blasting the next one without needing to cumbersomely move your giant beam pointer (and avoid all of the vibration and extra jitter that would entail). The smaller each individual aperture is, the larger the cone your beam can scan over. If you make each aperture smaller than the wavelength of the light it is emitting, your beam can be electronically steered over an entire hemisphere. While there are practical engineering issues to getting sub-micron apertures to remain in a sufficiently regular array with active phase control for each, perhaps this is something that can be done by a sufficiently advanced civilization. And even without sub-wavelength apertures, a tiled array of apertures with phase control would still have benefits even if the electronic beam steering is in a somewhat more restricted cone.</div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=975&oldid=prev Lwcamp: /* Interference and Phased Arrays */ 2022-01-12T04:48:13Z

<p><span dir="auto"><span class="autocomment">Interference and Phased Arrays</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 21:48, 11 January 2022</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l45">Line 45:</td> <td colspan="2" class="diff-lineno">Line 45:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Diffraction, it turns out, is just a special kind of interference. It is the pattern you get when you consider the waves of each different part of the aperture interfering with each other.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Diffraction, it turns out, is just a special kind of interference. It is the pattern you get when you consider the waves of each different part of the aperture interfering with each other.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>So here's an example of how we can use diffraction and interference to our benefit. here is a picture that shows a hexagonal aperture on the left and the diffraction pattern <del style="font-weight: bold; text-decoration: none;">in </del>produces at the target on the right (not to scale):</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>So here's an example of how we can use diffraction and interference to our benefit. here is a picture that shows a hexagonal aperture on the left and the diffraction pattern <ins style="font-weight: bold; text-decoration: none;">it </ins>produces at the target on the right (not to scale):</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table class="center" style="width: auto; margin-left: auto; margin-right: auto;"></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table class="center" style="width: auto; margin-left: auto; margin-right: auto;"></div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=505&oldid=prev Lwcamp: /* Interference and Phased Arrays */ 2021-10-17T04:39:53Z

<p><span dir="auto"><span class="autocomment">Interference and Phased Arrays</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 21:39, 16 October 2021</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l61">Line 61:</td> <td colspan="2" class="diff-lineno">Line 61:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div></table></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Phase control can be done electronically, so if you had paired apertures like in the above picture, you could rapidly scan <del style="font-weight: bold; text-decoration: none;">toe </del>horizontal bar of the interference fringe up and down across the spot without moving any mechanical component.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Phase control can be done electronically, so if you had paired apertures like in the above picture, you could rapidly scan <ins style="font-weight: bold; text-decoration: none;">the </ins>horizontal bar of the interference fringe up and down across the spot without moving any mechanical component.</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>But let's do better than that.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>But let's do better than that.</div></td></tr> </table>

Lwcamp https://www.galacticlibrary.net/mediawiki-1.41.1/index.php?title=Diffraction&diff=504&oldid=prev Lwcamp: /* Interference and Phased Arrays */ 2021-10-17T04:31:09Z

<p><span dir="auto"><span class="autocomment">Interference and Phased Arrays</span></span></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 21:31, 16 October 2021</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l83">Line 83:</td> <td colspan="2" class="diff-lineno">Line 83:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table border=1></div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><table border=1></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"><tr><td></ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Do you like math?</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Do you like math?</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr> </table>

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