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Entry  Wed Mar 30 12:55:54 2011, Aidan, Laser, Hartmann sensor, Prism modulation experiment 
    Reply  Thu Mar 31 11:27:02 2011, Aidan, Laser, Hartmann sensor, Prism modulation experiment 
Message ID: 130     Entry time: Thu Mar 31 11:27:02 2011     In reply to: 129
Author: Aidan 
Type: Laser 
Category: Hartmann sensor 
Subject: Prism modulation experiment 

I changed the drive amplitude on the function generator to 0.05Vpp and have measured the angle of deflection by bouncing a laser off the laser mirror and projecting it 5.23m onto the wall. The total displacement of the spot was ~3.3mm +/- 0.4mm, so the amplitude of the angular signal is 1.6mm/5.23m ~ 3.1E-4 radians. The Hartmann Sensor should measure a prism of corresponding magnitude.

The frequency is still 10mHz.


I've set up a quick experiment to modulate the angle of the Hartmann sensor probe beam at 10mHz and to monitor the measured prism. The beam from the SLED is collimated by a lens and this is incident on a galvo mirror. The reflection travels around 19" and is incident on the HWS. When the galvo mirror is sent a 1.1Vpp sine wave, then beam moves around +/- 0.5" on the surface of the Hartmann sensor, giving around 50mrad per Vpp.

The galvo is currently being sent a 0.02Vpp sine wave at 10mHz.


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