Custom ring tirf alignment issue

[Joe Ping-Lin Hsiao]

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Hi, we built a custom ring tirf system with multiple fast steering mirrors in the light path. Each mirror can tilt in both X and Y, so to achieve ring tirf we only need to control one of them.

The system works fine except for one issue. In our system, the laser beam goes into the objective from below. From time to time I found that the laser beam would be off the center axis, so I have to check that every time before experiments and to re-align the beam if it's off. Is this normal?

[Craig Brideau]

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Yes. Any environmental drift in the lab will cause mirrors and optics to flex a small amount. Even turning the laser on and off will cause small movements as the laser heats up and cools down. Unless you thermo-stabilize everything you will always see small amounts of drift. Better optical mounts and lasers will alleviate this somewhat, but it is very hard to eliminate completely. If the adjustments you have to make are fairly small then you are doing well.

Craig

On Mon, Nov 21, 2016 at 8:09 AM, Joe Ping-Lin Hsiao <[hidden email]> wrote:

***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. *****

Hi, we built a custom ring tirf system with multiple fast steering mirrors in the light path. Each mirror can tilt in both X and Y, so to achieve ring tirf we only need to control one of them.

The system works fine except for one issue. In our system, the laser beam goes into the objective from below. From time to time I found that the laser beam would be off the center axis, so I have to check that every time before experiments and to re-align the beam if it's off. Is this normal?

[0000001ed7f52e4a-dmarc-request]

***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. *****

Not a confocal microscope, but great little device with LED illumination and cellphone clip on magnets:

https://www.kickstarter.com/projects/276738145/foldscope-the-origami-paper-microscope

(no commercial interest)

best wishes

Andreas

[Joe Ping-Lin Hsiao]

***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. *****

Thanks Craig, the adjustment I have to do is actually pretty small. Also I found that switch to a different filter cube would change the beam's direction a little bit. I might have to compensate that by defining a new zero-volt position on the steering mirror.

On Mon, Nov 21, 2016 at 1:25 PM, Craig Brideau <[hidden email]> wrote:

***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. *****

Yes. Any environmental drift in the lab will cause mirrors and optics to flex a small amount. Even turning the laser on and off will cause small movements as the laser heats up and cools down. Unless you thermo-stabilize everything you will always see small amounts of drift. Better optical mounts and lasers will alleviate this somewhat, but it is very hard to eliminate completely. If the adjustments you have to make are fairly small then you are doing well.

Craig

On Mon, Nov 21, 2016 at 8:09 AM, Joe Ping-Lin Hsiao <[hidden email]> wrote:

***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. *****

Hi, we built a custom ring tirf system with multiple fast steering mirrors in the light path. Each mirror can tilt in both X and Y, so to achieve ring tirf we only need to control one of them.

The system works fine except for one issue. In our system, the laser beam goes into the objective from below. From time to time I found that the laser beam would be off the center axis, so I have to check that every time before experiments and to re-align the beam if it's off. Is this normal?