Wave Plate Measuring Principle And Technology Research

In this paper, a novel method is proposed to measure the phase retardation of wave plates after the progress in measurement technology of their phase is introduced. Next, an automatic measurement system is designed that consists of the optic-mechanical parts, the electrical circuits and the computer software. In this system, a standard wave plate act as compensator, the stepping motor is used to drive the analyzer to realize phase shifting, and a grating encoder is used to measure its rotating angle. While the beam comes out from the analyzer, the photoelectric detector gets its intensity, and then the signals is magnified and filtered and sent to computer through its serial port. The wave plates can be measured with this system even if their optical axes are unknown, and the phase retardation can be precisely obtained by means of phase shifting calculation and least squares estimation. In the meantime, this system is convenient to measure many kinds of wave plates rapidly.