Determination of optical parameters for laser heterodyne detecting system

Laser heterodyne measurement is a detection technique with high sensitivity and it has wide applications in the domains of ranging, tachometry, guidance, tracking and so on. Optical system plays an important part in heterodyne receive optics. The reasonable selection of performance parameters of optical system has direct influence upon the ability of system to detect objects. Primary parameters and living examples are given to show how to determine the parameter of optical system and make diffraction spot radius match detector size in laser heterodyne detecting system with both receiver and transmitter. The parameters determined accord with the condition given by antenna theorem and meet demands of detector hybrid frequency.