Koch Lab:Research/AOD tidbits - Revision history

http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&feed=atom&action=history Koch Lab:Research/AOD tidbits - Revision history 2013-05-19T09:50:00Z Revision history for this page on the wiki MediaWiki 1.13.2 http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=163451&oldid=prev Steven J. Koch: /* Amazing diffraction patterns caused by acousto-optic effects */ 2007-10-31T05:51:27Z

<p><span class="autocomment"><a href="/index.php?title=/AOD_Loops&action=edit&redlink=1" class="new" title="/AOD Loops (not yet written)">Amazing diffraction patterns caused by acousto-optic effects</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:51, 31 October 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers, one of which ([http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1076617 Naoya Uchida 1971]) shows pictures of a "new type of Schaefer-Bergmann diffraction patterns" which I think they call "abnormal Bragg reflection".  Another paper ([http://prola.aps.org/abstract/PR/v52/i3/p223_1 Mueller 1937]) shows calculations of  loopy diffraction patterns.  Steve isn't exactly clear on what "Schaefer-Bergmann Diffraction is because the paper [http://www.springerlink.com/content/j06655j2441p21g7/ (Schaefer and Bergmann 1934)] is not available and not in English.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers, one of which ([http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1076617 Naoya Uchida 1971]) shows pictures of a "new type of <ins class="diffchange diffchange-inline">[http://en.wikipedia.org/wiki/Schaefer-Bergmann_diffraction </ins>Schaefer-Bergmann diffraction<ins class="diffchange diffchange-inline">] </ins>patterns" which I think they call "abnormal Bragg reflection".  Another paper ([http://prola.aps.org/abstract/PR/v52/i3/p223_1 Mueller 1937]) shows calculations of  loopy diffraction patterns.  Steve isn't exactly clear on what "Schaefer-Bergmann Diffraction<ins class="diffchange diffchange-inline">" </ins>is because the paper [http://www.springerlink.com/content/j06655j2441p21g7/ (Schaefer and Bergmann 1934)] is not available and not in English.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr>   </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=127906&oldid=prev Steven J. Koch: /* Amazing diffraction patterns caused by acousto-optic effects */ 2007-07-05T22:30:45Z

<p><span class="autocomment"><a href="/index.php?title=/AOD_Loops&action=edit&redlink=1" class="new" title="/AOD Loops (not yet written)">Amazing diffraction patterns caused by acousto-optic effects</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 22:30, 5 July 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers, one of which ([http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1076617 Naoya Uchida 1971]) shows pictures of a "new type of Schaefer-Bergmann diffraction patterns" which I think they call "abnormal Bragg reflection".  Another paper ([http://prola.aps.org/abstract/PR/v52/i3/p223_1 Mueller 1937]) shows calculations of  loopy diffraction patterns.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers, one of which ([http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1076617 Naoya Uchida 1971]) shows pictures of a "new type of Schaefer-Bergmann diffraction patterns" which I think they call "abnormal Bragg reflection".  Another paper ([http://prola.aps.org/abstract/PR/v52/i3/p223_1 Mueller 1937]) shows calculations of  loopy diffraction patterns<ins class="diffchange diffchange-inline">.  Steve isn't exactly clear on what "Schaefer-Bergmann Diffraction is because the paper [http://www.springerlink.com/content/j06655j2441p21g7/ (Schaefer and Bergmann 1934)] is not available and not in English</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=127903&oldid=prev Steven J. Koch: /* Amazing diffraction patterns caused by acousto-optic effects */ 2007-07-05T22:25:50Z

<p><span class="autocomment"><a href="/index.php?title=/AOD_Loops&action=edit&redlink=1" class="new" title="/AOD Loops (not yet written)">Amazing diffraction patterns caused by acousto-optic effects</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 22:25, 5 July 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Loops.png|right|thumb|Loops]]</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers which <del class="diffchange diffchange-inline">indicated that this was due to </del>Schaefer-Bergmann diffraction.  <del class="diffchange diffchange-inline">Schaefer-Bergmann diffraction surprisingly doesn't have a wikipedia article, but is due to acousto-optic diffraction in birefrigent materials</del>.  <del class="diffchange diffchange-inline">Steve never got far enough to understand this</del>.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers<ins class="diffchange diffchange-inline">, one of </ins>which <ins class="diffchange diffchange-inline">([http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1076617 Naoya Uchida 1971]) shows pictures of a "new type of </ins>Schaefer-Bergmann diffraction <ins class="diffchange diffchange-inline">patterns" which I think they call "abnormal Bragg reflection"</ins>.  <ins class="diffchange diffchange-inline">Another paper ([http://prola</ins>.<ins class="diffchange diffchange-inline">aps.org/abstract/PR/v52/i3/p223_1 Mueller 1937]) shows calculations of </ins> <ins class="diffchange diffchange-inline">loopy diffraction patterns</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Comparison with the cross-hatching beam distortion indicates that the loops are possibly the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124048&oldid=prev Steven J. Koch: /* Amazing diffraction patterns caused by acousto-optic effects */ 2007-06-20T06:01:08Z

<p><span class="autocomment"><a href="/index.php?title=/AOD_Loops&action=edit&redlink=1" class="new" title="/AOD Loops (not yet written)">Amazing diffraction patterns caused by acousto-optic effects</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 06:01, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 11:</td> <td colspan="2" class="diff-lineno">Line 11:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>Schaefer-Bergmann diffraction<del class="diffchange diffchange-inline">? </del> <del class="diffchange diffchange-inline">Possible </del>the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">[[Image:Loops.png|right|thumb|Loops]]</ins></div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div><del class="diffchange diffchange-inline">[[Image:Loops.png|thumb|Loops]]</del><br style="clear:both;"/></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">The diffraction pattern shown in the picture is the result of shining a HeNe laser through an AOD designed for use with a 1064 nm laser.  So, this is not the correct usage of the AOD, but the pattern displayed is similar to what Steve saw using a 1064 nm beam (visualized either with an IR card or possibly by viewing with a CCD camera) and it was much easier at the time to take a picture of a visible laser beam.  Steve found the pattern amazing, first because it just looks cool, and second because the simple understanding of acousto-optic diffraction (Bragg diffraction) cannot explain the crazy loop diffraction.  Steve actually walked to the engineering library (in the old days of the 1990s you had to go to the library) and photocopied some papers which indicated that this was due to </ins>Schaefer-Bergmann diffraction<ins class="diffchange diffchange-inline">. </ins> <ins class="diffchange diffchange-inline">Schaefer-Bergmann diffraction surprisingly doesn't have a wikipedia article, but is due to acousto-optic diffraction in birefrigent materials.  Steve never got far enough to understand this.</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div> </div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">Comparison with the cross-hatching beam distortion indicates that the loops are possibly </ins>the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><br style="clear:both;"/></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Crosshatch Pattern|Crosshatching in laser caused by AOD]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Crosshatch Pattern|Crosshatching in laser caused by AOD]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Beam before AOD.JPG|thumb|Before AOD]] [[Image:Beam after deflection through AOD.png|thumb|After AOD]]<br style="clear:both;"/></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Beam before AOD.JPG|thumb|Before AOD]] [[Image:Beam after deflection through AOD.png|thumb|After AOD]]<br style="clear:both;"/></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Efficiency|Efficiency and "flatness" of AODs]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Efficiency|Efficiency and "flatness" of AODs]]==</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124047&oldid=prev Steven J. Koch: /* Wiggles caused by AOD on the quadrant photodiode */ 2007-06-20T05:54:52Z

<p><span class="autocomment"><a href="/index.php?title=/Detector_Wiggle_Disaster&action=edit&redlink=1" class="new" title="/Detector Wiggle Disaster (not yet written)">Wiggles caused by AOD on the quadrant photodiode</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:54, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|right|thumb|wiggles]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|right|thumb|wiggles]]</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs<ins class="diffchange diffchange-inline">.  Some of our thoughts:</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* Wiggles definitely caused by AOD and a repeatable function of frequency and AOD power</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* Wiggles perhaps worse due to imaging of AOD onto detector (many labs image a plane between the AODs, which may temper the wiggle problem)</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* A wiggle subtraction array can be used, level of success unknown (Steve et al. used an "offset array" subtraction, which accounts for the wiggles at a fixed frequency, variable AOD power).</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">* Wiggles are probably not in focus in sample plane and so do not affect the trapping force...so a separate detection beam probably negates wiggles problem</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><br style="clear:both;"/></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><br style="clear:both;"/></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124046&oldid=prev Steven J. Koch at 05:50, 20 June 2007 2007-06-20T05:50:39Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:50, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">[[Image:Detector Wiggles for Various AOD Powers.png|right|thumb|wiggles]]</ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div><del class="diffchange diffchange-inline">[[Image:Detector Wiggles for Various AOD Powers.png|right|thumb|wiggles]]</del><br style="clear:both;"/></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><br style="clear:both;"/></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124045&oldid=prev Steven J. Koch at 05:50, 20 June 2007 2007-06-20T05:50:09Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:50, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<br style="clear:both;"/></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png<ins class="diffchange diffchange-inline">|right</ins>|thumb|wiggles]]<br style="clear:both;"/></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124044&oldid=prev Steven J. Koch at 05:49, 20 June 2007 2007-06-20T05:49:54Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:49, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div><del style="color: red; font-weight: bold; text-decoration: none;">[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<br style="clear:both;"/></del></div></td><td colspan="2"> </td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<br style="clear:both;"/></ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124043&oldid=prev Steven J. Koch: /* Wiggles caused by AOD on the quadrant photodiode */ 2007-06-20T05:49:37Z

<p><span class="autocomment"><a href="/index.php?title=/Detector_Wiggle_Disaster&action=edit&redlink=1" class="new" title="/Detector Wiggle Disaster (not yet written)">Wiggles caused by AOD on the quadrant photodiode</a></span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:49, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<br style="clear:both;"/></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<br style="clear:both;"/></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">After aligning the optical tweezers (at Cornell, Wanglab, see [[Koch_Lab:Publications]] 2002 Biophys J article) Steve, Richard and others discovered that using our AOD to steer the optical trap in the sample plane produces huge "wiggles" on the detector.  These wiggles could add as much as 10 nm of error into the detection signal, which was unacceptable.  Steve studied the hell out of this for over a month and in the end, use of the AODs for other than intensity modulation was abandonded, and the piezo stage was used for 1-D stretching.  Many unpublished things were discovered along the way, which could be useful to other optical tweezers labs or others using AODs.</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Schaefer-Bergmann diffraction?  Possible the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Schaefer-Bergmann diffraction?  Possible the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr>  </table>

Steven J. Koch http://openwetware.org/index.php?title=Koch_Lab:Research/AOD_tidbits&diff=124042&oldid=prev Steven J. Koch at 05:38, 20 June 2007 2007-06-20T05:38:28Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 05:38, 20 June 2007</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/Detector Wiggle Disaster|Wiggles caused by AOD on the quadrant photodiode]]==</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>[[Image:Detector Wiggles for Various AOD Powers.png|thumb|wiggles]]<ins class="diffchange diffchange-inline"><br style="clear:both;"/></ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==[[/AOD Loops|Amazing diffraction patterns caused by acousto-optic effects]]==</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Schaefer-Bergmann diffraction?  Possible the root cause of the AOD cross-hatching and detector wiggles?</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Schaefer-Bergmann diffraction?  Possible the root cause of the AOD cross-hatching and detector wiggles?</div></td></tr>  </table>

Steven J. Koch