A Dual Femtosecond Laser Frequency Comb Synthetic Wave Interferometric Ranging System

Abstract

The invention relates to a composite wave interferometry ranging distance system with two femtosecond laser frequency combs. The composite wave interferometry ranging distance system is characterized in that a first femtosecond laser frequency comb emits an optical pulse to a first spectroscope, the optical pulse reflected by the first spectroscope is transmitted to a first corner reflector, and the optical pulse reflected by the first corner reflector is transmitted to a second spectroscope through the first spectroscope. The optical pulse transmitted by the first spectroscope is transmitted to a second corner reflector, and the optical pulse reflected by the second corner reflector is reflected to the second spectroscope through the first spectroscope. A second femtosecond laser frequency comb emits an optical pulse to the second spectroscope, the optical pulse transmitted by the second spectroscope and an optical pulse emitted by a Michelson interference system are mixed and transmitted to a third spectroscope, the optical pulse transmitted by the third spectroscope is received by a first photoelectric detector in a detection mode through a first narrow-band band-pass filter, and the optical pulse reflected by the third spectroscope is received by a second photoelectric detector in a detection mode through a second narrow-band band-pass filter. The first photoelectric detector and the second photoelectric detector are connected with an A / D converter connected with a signal processing unit through a corresponding data interface to process the received signal to obtain the required distance measuring value.

Description

technical field [0001] The invention relates to a laser distance measurement system, in particular to a dual femtosecond laser frequency comb synthetic wave interference distance measurement system suitable for absolute distance measurement. Background technique [0002] Traditional laser interferometry is an incremental distance measurement method, and there is an unambiguous distance of one-half wavelength. When the measured distance is greater than the unambiguous distance, it is necessary to set up a guide rail between the baseline and the target object. During the measurement process, the target object needs to move continuously along the guide rail to complete the fringe counting and achieve a wide range of distance measurement. Laser absolute distance measurement (distance measurement without guide rail) is a method to directly measure the distance between the baseline and the target object. Compared with the former, it has the advantages of wide application range and...

AI Technical Summary

Problems solved by technology

The problem with this method is that it can achieve very high measurement speed but the accuracy is not high enough for rough measurement, and it needs to take the average of multiple rough measurements when transitioning from rough measurement to fine measurement, which greatly reduces the speed of distance measurement.

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