Automatic polarisation analysis appts. - has two optical modulators controlled by square wave AC

摘要

The automatic polarisation analysis system has alight source (1) and a collimator lens system (2) followed by a monochromatic filter (3) passing light of 546 m u. There is a polariser whose optical axis is rotatable, it is driven by a servomotor. The polariser is followed by a quarter wave plate (2). The test sample (5) follows the quarter wave plate and is followed by a light modulating crystal (6). This is controlled by AC from a switching network (11). A square wave is produced. The first crystal (6) is followed by a quarter wave plate (7), a second crystal modulator (6') and an analyser (8). Lenses (9) focus the light onto a photocell (10).