Double-femtosecond laser frequency comb ranging system

Abstract

The invention relates to a double-femtosecond laser frequency comb ranging system. The double-femtosecond laser frequency comb ranging system is characterized in that a first femtosecond laser frequency comb transmits light pulses to a first frequency doubling crystal, the first frequency doubling crystal performs frequency doubling and transmits the two light pulses to a first light splitter, and the light pulses reflected by the first light splitter are transmitted to a light splitter through a first corner reflector and the first light splitter; the light pulses transmitted by the first light splitter are reflected to the light splitter through a second corner reflector and the first light splitter; a second femtosecond laser frequency comb transmits light pulses to a second frequency doubling crystal, and the second frequency doubling crystal performs frequency doubling and transmits the two light pulses to the light splitter simultaneously; the light pulses transmitted by the light splitter are mixed with light pulses emitted by a Michelson interference system, fundamental frequency light pulses of the mixed light pulses are transmitted to a first photoelectric detector through a color selective mirror, frequency doubling light pulses are reflected to a second photoelectric detector, the first photoelectric detector and the second photoelectric detector are connected to a central processing unit through an analog to digital (A / D) acquisition card, and the central processing unit processes signals to obtain a distance measuring value. The double-femtosecond laser frequency comb ranging system is widely applied to laser absolute distance measurement.

Description

technical field [0001] The invention relates to a laser distance measurement system, in particular to a dual femtosecond laser frequency comb distance measurement system suitable for absolute distance measurement. Background technique [0002] The traditional laser interferometry is an incremental distance measurement method, which needs to set up a guide rail between the baseline and the target object, and the target object needs to move continuously along the guide rail during the measurement process. 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 simple operation, so it has strong applications in the field of industry and aerospace Demands and prospects, on the one hand, in large-scale mechanical equipment systems such as high-speed railways, large aircraft, nuclear power and w...

AI Technical Summary

Problems solved by technology

However, this ranging system still needs to face the problem of air refractive index correction, because in high-precision distance measurement, the correction of air refractive index is crucial to the measurement accuracy, and it is usually necessary to measure the air temperature and air pressure along the measurement path and the distribution of atmospheric parameters such as humidity, and then use empirical formulas such as Allen's formula to calculate the air refractive index

However, in long-distance measurement, it is difficult to accurately measure the distribution of atmospheric parameters, which will inevitably affect the calculation accuracy of the air refractive index, thereby affecting the ranging accuracy

In addition, in some practical applications of distance measurement, it is very inconvenient to measure the distribution of atmospheric parameters, which will also affect the correction of air refractive index

Images