Study on Detecting Laser Interference Fringes Using Four-Quadrant Optoelectronic Detectors

The spatial arrangement of symmetry four-quadrant optoelectronic detectors to detect laser interference fringes and the way to get a couple of quadrature signals are analyzed in this paper. The causes for measurement errors in detecting laser interference fringes using four-quadrant optoelectronic detectors are analyzed and a method combining hardware circuits and software is proposed to compensate measurement errors caused by the signal errors. The measurement error of laser interferometer using four quadrant photoelectric detectors is discuss using Michelson interferometer as an example and the measurement error formula is given. The laser interferometer using four-quadrant optoelectronic detectors has been successfully applied in the vertical scanning system developed in our laboratory. Experiments proved that the non-linear error of the laser interferometer is less than 0.05% and the actual effective resolution is less than 1nm.