Laser interferometer optical path difference location method and system

Abstract

The invention discloses an optical path folding laser interferometer system which is simple and compact in structure and used for precisely locating the difference of two optical paths of a movable mirror and a stationary mirror of a Fourier transform spectrometer. By combining a pyramidal retroreflector and a reflecting mirror, which are compact in spatial layout, the optical path of a movable arm of the laser interferometer are folded for four times, and the period of an interference pattern generated by the interferometer is reduced by four times. Through the photoelectric transformation of a zero-passage detection circuit, a pulse signal with identical optical path difference interval being less than 100 nanometers, and a detector for triggering the Fourier transform spectrometer is used for sampling the interference pattern of a signal to be detected. Due to the adoption of the laser interferometer system, not only can the working spectrum of the Fourier transform spectrometer be expanded to near ultraviolet (to 350 nanometers) of a shortwave band, but also the high measurement precision advantage of the Fourier transform spectrometer can be maintained. Therefore, an ultraviolet-visible light Fourier transform spectrometer which is realized through the method and the system can be widely applied in multiple fields such as chemistry, biology, medicine, materials and optics.

Description

technical field [0001] The invention relates to a laser interferometer optical path difference positioning method and system. Background technique [0002] Compared with dispersive spectrometers, Fourier transform spectrometers have the following obvious inherent optical characteristics advantages in the long-wave infrared band: 1 Multi-channel (Multiplex); 2 High luminous flux (Throughput); 3 High spectral measurement accuracy (Connes); 4 Wide measurement band; 5 high / tunable spectral resolution; 6 consistent resolution across all bands. Therefore, Fourier transform spectrometer is widely used in the measurement of infrared absorption spectrum, and is more widely called Fourier transform infrared spectrometer. Fourier transform infrared spectrometer can perform qualitative and quantitative analysis on samples, and has the characteristics of high signal-to-noise ratio, good reproducibility and fast scanning speed, etc. identification, forensic identification and other fie...

AI Technical Summary

Problems solved by technology

However, these methods have some intolerable shortcomings, such as: high-precision sampling with equal optical path difference cannot be achieved; high-precision positioning can only be achieved at a very short distance; environmental factors such as temperature and pressure are demanding; the cost is too expensive, Not suitable for routine instrumentation, etc.

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