Optical Tweezer Laser Focus/Alignment Troubleshooting

Context: Undergrad
Thread starter wheatie
Start date Apr 9, 2024
Tags

Optical tweezers

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SUMMARY

The discussion centers on troubleshooting an optical tweezer setup that includes a beam expander and a dichroic mirror, which fills the objective's aperture. The primary concerns are verifying whether the laser is effectively trapping particles and ensuring that the laser and camera are focused on the same point. Participants are seeking methods to confirm laser focus and alignment with the camera's field of view (FOV).

PREREQUISITES

Understanding of optical tweezer systems
Familiarity with beam expanders and dichroic mirrors
Knowledge of microscope optics and alignment techniques
Experience with laser focus verification methods

NEXT STEPS

Research methods for verifying laser focus in optical tweezers
Learn about alignment techniques for cameras and lasers in microscopy
Investigate the use of calibration beads for optical trapping verification
Explore software tools for analyzing particle trapping in optical tweezers

USEFUL FOR

Researchers and technicians working with optical tweezers, optical engineers, and anyone involved in microscopy and laser alignment troubleshooting.

Apr 9, 2024

wheatie

TL;DR: Optical Tweezer Trapping Help

Currently we have an optical tweezer setup that has a beam expander + dichroic mirror that fills the aperture of the objective, and a microscope that is able to look into the aperture and see a diameter of about 30 microns.
We have been stuck for a couple weeks now, as we do not know if our laser is actually trapping any particle/if the trapping is occurring within the fov of the camera.
Our questions would be:
How can we tell if our laser is focused.
How can we tell if our camera and laser is focused at the same point.

I've included a photo of our current setup.
Thank you!