阅读说明：本技术 一种微谐振腔光学频率梳相位法测量系统 (Micro-resonant cavity optical frequency comb phase method measuring system ) 是由 张福民 宋明宇 郑继辉 姚思涵 曲兴华 马鑫 于 2020-07-20 设计创作，主要内容包括：本发明涉及一种微谐振腔光学频率梳相位法测量系统,用于高精度长度测量。所述的微谐振腔光学频率梳相位法测量系统包括光源、准直镜、分光镜、光电探测器、相位调制器、计算机,其中光源、准直镜构成光输出模块,实现准直光源的输出；分光镜、光电探测器、被测物体构成光学测量模块,实现利用被测物体的距离对光信号相位的调制；相位调制器、计算机构成信号处理模块。通过微谐振腔光学频率梳的自拍频,对光学信号的相位调制,进而实现对距离的较高精度测量。(The invention relates to a micro-resonant cavity optical frequency comb phase method measuring system which is used for high-precision length measurement. The micro-resonant cavity optical frequency comb phase method measuring system comprises a light source, a collimating mirror, a spectroscope, a photoelectric detector, a phase modulator and a computer, wherein the light source and the collimating mirror form a light output module to realize the output of a collimated light source; the spectroscope, the photoelectric detector and the measured object form an optical measuring module to realize the modulation of the phase of the optical signal by using the distance of the measured object; the phase modulator and the computing mechanism form a signal processing module. The self-timer frequency of the micro-resonant cavity optical frequency comb is used for modulating the phase of an optical signal, so that the distance can be measured with higher precision.)

1. A micro-resonant cavity optical frequency comb phase method measuring system is characterized by comprising:

the light output module consists of a light source and a collimating mirror and is used for generating a collimated micro-resonant cavity optical frequency comb;

the optical measurement module consists of a spectroscope, a photoelectric detector and a measured object, and the spectroscope combs the optical frequency of the micro-resonant cavity into reference light and measurement light; respectively detecting the reference light and the measuring light by a photoelectric detector to obtain a reference light signal and a measuring light signal, and modulating the phase of the measuring light by using the reference light signal and the measuring light signal and utilizing the distance of the measured object to obtain one-dimensional distance information of the measured object in the emergent light direction;

and the signal processing module is composed of a phase modulator and a computer and is used for processing the reference light signal and the measuring light signal generated by the photoelectric detector and calculating to obtain one-dimensional distance information of the measured object.

2. The microresonator optical frequency comb phase method measurement system of claim 1, wherein the microresonator optical frequency comb is coupled to a collimating mirror via an optical fiber to obtain a collimated microresonator optical frequency comb.

3. The microresonator optical frequency comb phase measurement system of claim 1, wherein the optical measurement module comprises a beam splitter, a photodetector, and a measured object, the collimated microresonator output by the optical output module is divided into reference light and measurement light by the beam splitter, the reference light is directly detected by the photodetector, the measurement light is irradiated onto the measured object, reflected by the surface of the measured object, and then reflected by the beam splitter to another photodetector for reception, and the two photodetectors respectively obtain a reference light signal and a measurement light signal generated by a self-heterodyne frequency effect.

4. The microresonator optical frequency comb phasing measurement system of claim 1, wherein the signal processing module comprises:

the phase modulator is provided with A, B two-path input ends and I, Q two-path output ends, the photoelectric detector is connected with the input ends of the phase modulator by using a signal line, the reference light signal and the measuring light signal are respectively input by the two-path input ends, and the I signal and the Q signal are respectively output by the I, Q two-path output ends after the reference light signal and the measuring light signal are processed by the phase modulator;

the computer is used for calculating the signals generated by the phase modulator, the I, Q output end of the phase modulator is connected with the computer by using a signal line, the I signal and the Q signal are processed to obtain the distance information of the object to be measured, and the relationship between the I signal and the Q signal and the distance of the object to be measured is as follows:

where c is the speed of light propagation in air, Q is the Q signal generated by said phase modulator, I is the I signal generated by said phase modulator, f_rThe repetition frequency of the optical frequency comb of the micro resonant cavity.

Technical Field

The invention relates to the technical field of one-dimensional distance measurement, in particular to a micro-resonant cavity optical frequency comb phase method measuring system.

Technical Field

The one-dimensional distance measurement technology is widely applied to the fields of industrial assembly, aerospace, industrial part production and the like, and the traditional one-dimensional distance laser measurement technology is mainly divided into the following aspects: a time-of-flight method for calculating a distance using a time-of-flight of the laser; an interferometry for calculating a distance by interference using the reference light and the measurement light; a phase method of calculating a distance from the phase of the measured light.

Because of the limitation of the response time of the detector, the flight time method is suitable for the measurement occasions with lower measurement precision requirements; due to the periodicity of the optical interference signal, the interferometry cannot perform absolute measurement of distance; the phase method has low measurement accuracy because the frequency of the conventional laser is high and the phase resolution is low.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a micro-resonant cavity optical frequency comb phase method measuring system which can realize high-precision one-dimensional distance measurement.

The invention is realized by the following technical scheme:

the invention provides a micro-resonant cavity optical frequency comb phase method measuring system, which comprises:

and the light output module consists of a light source and a collimating mirror and is used for generating a collimated micro-resonant cavity optical frequency comb.

The optical measuring module is composed of a spectroscope, a photoelectric detector and a measured object and is used for measuring the one-dimensional distance of the measured object.

And the signal processing module is composed of a phase modulator and a computer and is used for processing the reference light signal and the measuring light signal generated by the photoelectric detector and calculating to obtain one-dimensional distance information of the measured object.

The light output module comprises a light source and a collimating mirror. The light source is a micro resonant cavity optical frequency comb. And connecting the micro-resonant cavity frequency comb with a collimating mirror through an optical fiber to obtain the collimated micro-resonant cavity optical frequency comb.

The optical measurement module comprises a spectroscope, a photoelectric detector and a measured object. The collimated micro-resonator optical frequency comb output by the optical output module is divided into reference light and measuring light by the beam splitter.

The reference light is directly detected by the photoelectric detector, the measuring light irradiates on the measured object, and is reflected by the surface of the measured object and then is reflected to another photoelectric detector by the spectroscope to be received. The two photodetectors respectively obtain a reference light signal and a measurement light signal resulting from the self-clocking effect.

The signal processing module comprises:

the phase modulator has A, B two-way inputs and I, Q two-way outputs. The two photoelectric detectors are connected with A, B input ends of a phase modulator by using signal lines, the reference light signals and the measuring light signals are respectively input by the two input ends, and I signals and Q signals are respectively output by I, Q two output ends after the reference light signals and the measuring light signals are processed by the phase modulator.

The computer is used for calculating the signal generated by the phase modulator. The I, Q output end of the phase modulator is connected with a computer by using a signal wire, and the I signal and the Q signal are processed to obtain the distance information of the measured object. The relationship between the I signal and the Q signal and the distance of the measured object is as follows:

where c is the speed of light propagation in air, Q is the Q signal generated by said phase modulator, I is the I signal generated by said phase modulator, f_rThe repetition frequency of the optical frequency comb of the micro resonant cavity.

Compared with the prior art, the invention has the following advantages:

the invention can obtain the electric signal with high-precision frequency through the frequency domain characteristic of the microcavity optical frequency comb, and has the advantages of high precision, simple and convenient measurement and the like because the system has simple structure and convenient signal processing and the phase modulator has high phase resolution.

Drawings

FIG. 1 is a diagram illustrating an overall structure of a micro-resonator optical frequency comb phase method measurement system according to an embodiment of the present invention.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

The invention relates to a micro-resonant cavity optical frequency comb phase method measuring system, the structure diagram of which is shown in figure 1, wherein an optical output module is composed of a light source 1 and a collimating mirror 2, the light source 1 is connected to the collimating mirror 2 through an optical fiber and is used for generating a collimated micro-resonant cavity optical frequency comb.

The optical measuring module is composed of the optical lens 5, the photoelectric detector 3, the photoelectric detector 4 and the measured object 6. The spectroscope 5 combs the collimated micro-resonant cavity optical frequency into reference light and measuring light; the photodetectors 3, 4 detect the reference light and the measurement light, respectively, to obtain a reference light signal and a measurement light signal.

The signal processing module is composed of the phase modulator 7 and a computer 8. And a phase modulator 7 having A, B two-way input terminal and I, Q two-way output terminal.

The photodetectors 3 and 4 are connected to the input end A, B of the phase modulator 7 by using signal lines, the reference optical signal and the measurement optical signal are respectively input to the two input ends, and the reference optical signal and the measurement optical signal are processed by the phase modulator 7 and then respectively output an I signal and a Q signal from the I, Q two output ends.

And the computer 8 is used for calculating the signal generated by the phase modulator 7. The output terminal I, Q of the phase modulator 7 is connected to the computer 8 by a signal line, and the I signal and the Q signal are processed to obtain distance information of the object to be measured.

Specifically, the light output module comprises a light source 1 and a collimating mirror 2. The light source 1 is a micro-resonant cavity optical frequency comb. A light source 1 is connected to a collimating mirror 2 via an optical fiber for generating a collimated microresonator optical frequency comb.

Specifically, the optical measurement module is composed of the spectroscope 5 and the photodetectors 3 and 4. When the micro-resonator optical frequency comb generated by the optical output module passes through the spectroscope 5, the spectroscope 5 divides the micro-resonator optical frequency comb generated by the optical output module into reference light and measurement light, wherein the reference light is directly detected by the photoelectric detector 3, the measurement light is reflected by the measured object 6 and then reflected by the spectroscope 5 and detected by the photoelectric detector 4, and a reference light signal and a measurement light signal generated by self-timer frequency are respectively obtained based on the reference light and the measurement light.

The reference optical signal may be expressed as:

I_r＝∑_N＝1∑_nA_1nA_1n+Ncos(2Nπf_rt)；

wherein A is_1nAnd A_1n+NRespectively is the amplitude of the frequency component of the microcavity optical frequency comb corresponding to different serial numbers, N is an integer, f_rIs the repetition frequency of the optical frequency comb of the micro-resonant cavity, and t is time.

The measurement light signal can be expressed as:

I_m＝∑_N＝1∑_nA_2nA_2n+Ncos(2Nπf_rt-2Nπf_rτ)；

wherein A is_2nAnd A_2n+NRespectively is the amplitude of the frequency component of the microcavity optical frequency comb corresponding to different serial numbers, N is an integer, f_rIs the repetition frequency of the microresonator comb, t is the time, and τ is the time delay of the measurement light due to the distance being measured.

Since the response of the photodetectors 3, 4 can be chosen, the first order signal is chosen for measurement. The reference optical signal may be expressed as:

I_r＝∑_nA_1nA_1n+1cos(2πf_rt)；

wherein A is_1nAnd A_1n+1The amplitudes, f, of the frequency components of the microcavity optical frequency comb are of different orders_rIs the repetition frequency of the optical frequency comb of the micro-resonant cavity, and t is time.

The measurement light signal can be expressed as:

I_m＝∑_nA_2nA_2n+1cos(2πf_rt-2πf_rτ)；

wherein A is_2nAnd A_2n+1The microcavity optical frequency combs corresponding to different serial numbers respectivelyAmplitude of the frequency component of (f)_rIs the repetition frequency of the microresonator comb, t is the time, and τ is the time delay of the measurement light due to the distance being measured.

Specifically, the signal processing module is composed of the phase modulator 7 and the computer 8. The phase modulator is provided with A, B two-path input ends and I, Q two-path output ends, and has high phase discrimination precision. Through the connection of the signal lines, the reference light signal and the measurement light signal are respectively input to the two input ends A, B, and the reference light signal and the measurement light signal are processed by the phase modulator and then respectively output an I signal and a Q signal through the I, Q two output ends.

Where the I signal may be expressed as:

I＝cos(2πf_rτ)；

wherein f is_rτ is the time delay of the measurement light due to the measured distance, which is the repetition frequency of the microresonator optical frequency comb.

Where the Q signal may be expressed as:

Q＝sin(2πf_rτ)；

wherein f is_rτ is the time delay of the measurement light due to the measured distance, which is the repetition frequency of the microresonator optical frequency comb.

The computer is used for calculating the signal generated by the phase modulator, the phase modulator is connected with the computer by using a signal wire, the I signal and the Q signal are input into the computer for processing, and the distance information of the object to be measured is obtained, wherein the relationship between the I signal and the Q signal and the distance of the object to be measured is as follows:

where c is the speed of light propagation in air, Q is the Q signal generated by said phase modulator, I is the I signal generated by said phase modulator, f_rThe repetition frequency of the optical frequency comb of the micro resonant cavity.

The invention finally obtains the one-dimensional distance of the measured object. The above-mentioned embodiments are merely illustrative and not restrictive, and any modifications, equivalents, improvements and the like which come within the spirit and principle of the present invention are intended to be included within the scope of the present invention.