Electro-optic heterodyne interferometer.

We propose a new configuration for using a triangle-wave signal to drive the electro-optic modulator in an electro-optic heterodyne interferometer system. The new configuration is adapted to measure the phase retardation of a wave plate and the optical rotation angle of a chiral medium. By adding optic elements, the second-harmonic component amplitude of the interferometer photodetector output signal became proportional to the phase retardation or optical rotation angle of the samples being tested.