The first part of the experiment is the measurement of the numerical aperture of a planar waveguide. One determines the numerical aperture of the waveguide by observing the sudden loss of the optical beam when increasing the incidence of a laser beam.
The second part of the experiment is the measurement of optical coupling loss at and optical attenuation in a optical fiber. Through this experiment, one also practices coupling a laser beam into an optical fiber.
The third part of this experiment is to observe and select waveguide modes in an optical fiber. The mode selection is achieved by using a mode attenuator.