6D40.10 - Optical Interferometer
Demonstrate interference w/ an optical interferometer.
Allow plenty of time for setting up as the interferometer adjustments are very touchy. Project the interference image onto the wall. The beam position is adjusted via the steering mirror. Adjust the beam expander and laser aperture to expand the beam. Use the adjustment post to assist in initial set up. Set the post in the centre of the field then adjust ONE of the mirrors to eliminate all ghosting in the image output. This accomplished, adjust the arm stage to obtain a good crisp pattern.
When using the butane lighter, do not allow a flame, only observe the gas jet.
When using the vacuum cell, the initial pattern adjustment should be large ie there should not be many fringes visible as when the cell is introduced into the beam path, the additional glass introduced from the cell windows, will change the pattern significantly.