Advanced Optics Lab at San Jose State University. Ramen Bahuguna Department of Physics. We meet once a week for 4 hours. One hour lecture+3 hours of Lab There are about 6 labs and one project. The project takes about a month
Department of Physics
A variable slit is provided to the students. They are supposed to select a doublet lens of the proper focal length from a catalog such that for a typical source the lens is substantially illuminated. This in turn will illuminate a substantial part of the grating which will result in higher resolution.
The students select two doublet lenses for the telescope keeping in mind the fact that they have to overfill the pupil of their eyes so that the spectrum does not disappear on moving one's head slightly. Over filling the pupil will result in loss of intensity.
The students are asked to fabricate a holographic grating with 600 lines/mm. They calculate the angle between the two plane waves by the formula: d= λ/(2sinθ)
A laser beam is expanded, collimated and then split with a beam splitter and then combined with the help of mirrors on a holographic plate (PFG-01). Once fabricated, the grating constant is determined by diffracting a laser beam.
All the components are mounted on the turn table and aligned. Interaction with the mechanical shop is key to the success of the project. Finally the spectrometer is tested with a known spectrum.
finger a beam splitter and then combined with the help of mirrors on a holographic plate (PFG-01). Once fabricated, the grating constant is determined by diffracting a laser beam.
image of fingerprint
Camera l lens
A He-Ne laser is used as a source of light. The laser light is expanded by means of a microscopic objective. The beam is spatially filtered through a pin hole to remove diffraction artifacts. A hollow glass cell is placed in the path of the expanded beam. The expanded beam is collimated by a doublet mounted on a axial translational stage. The collimation is tested with a parallel plate shearing interferometer. The reading on the translational stage is recorded.
The glass cell is then filled with the given liquid. The collimation is obviously disturbed due to the apparent position of the laser point source. The lens is translated to get back the collimation using the interferometer and the new position of the stage recorded. From the two data one can easily calculate the refractive index of the liquid by the well known formula:
N= Real Depth/Apparent Depth
Interference bands on screen a beam splitter and then combined with the help of mirrors on a holographic plate (PFG-01). Once fabricated, the grating constant is determined by diffracting a laser beam.
Laser point source