Precision Phase Discriminator for the Heterodyne Interferometric Plasma-Density Measurement Technique

Abstract

The discriminator is intended for the plasma density recording systems based on optical heterodyne interferometry. The discriminator has a high phase resolution (10^–3 rad) and a virtually unlimited dynamic range in a modulation band of up to one-half of the carrier frequency (1 MHz). These features allow one to use the discriminator for recording phase shifts caused by both slow and fast plasma-density fluctuations on setups with high levels of thermal and mechanical influences on the interferometer.