Interferometric spectrum analysis device and analysis method

Abstract

The present invention provides an interferometric spectrum analysis device and analysis method, the analysis device comprising: a reference light source for generating a reference light signal; the coupler is used for coupling the input optical signal and the reference optical signal into a combined optical signal; the reflection cavity is used for receiving the combined light signal, moving the reflector and outputting a combined light interference signal; a circulator outputting the combined optical interference signal to the first optical filter and the second optical filter; the first optical filter is used for filtering the reference light interference signal to obtain an input light interference signal; the second optical filter is used for filtering the input light interference signal to obtain a reference light interference signal; the first optical signal detection unit is used for detecting the total power of an input optical signal; the second optical signal detection unit is used for detecting the power of the input optical interference signal; the third optical signal detection unit is used for detecting the power of the reference light interference signal; and the CPU is used for controlling the movement of the reflecting mirror in the reflecting cavity and acquiring the total power of the input light signal, the power of the input light interference signal and the power of the reference light interference signal.

Description

Technical Field

[0001] The present invention relates to the field of spectral technology, and in particular to an interference-type spectral analysis device and an analysis method. Background Art

[0002] Existing spectral analysis devices usually have the following structure:

[0003] 1: Dispersion-type spectrum analyzer, which uses a grating to disperse light of different wavelengths, and the dispersed light is analyzed by a detector array.

[0004] The spectral resolution of a grating-type spectrum analyzer is determined by the grating. The higher the required spectral resolution, the exponentially higher the grating production cost. The accuracy and cost of the grating restrict the performance of the grating-type spectrum analyzer.

[0005] 2: Interference spectrum analysis device, which uses the interference effect of light to analyze the interference image generated by the optical reflection cavity during the change process to obtain the spectrum analysis results.

[0006] The resolution of an interferometric spectrometer is determined solely by the length of the reflective cavity. The longer the cavity, the higher its spectral resolution. However, interferometric spectrometers require a cavity control system capable of precisely controlling cavity changes. Optical communications typically use wavelengths ranging from 1300nm to 1600nm, which is in the nanometer range. Nanometer-level spectral resolution requires precise control of the reflective cavity's changes. Large-stroke, high-precision cavity control systems are expensive, and this cost has significantly constrained the development of interferometric spectrometers.

[0007] Therefore, it is necessary to provide an interference spectrum analysis device and an analysis method to effectively solve the problems existing in existing interference spectrum analysis devices. Summary of the Invention

[0008] The present invention provides an interference-type spectrum analysis device and analysis method, which introduces a reference light source and infers the spectral composition of the input light signal by comparing and analyzing a known reference light signal and an input light signal in the same optical path, thereby reducing the dependence of the interference-type spectrum analysis device on a large-stroke and high-precision cavity control system.

[0009] An embodiment of the present invention provides an interference spectrum analysis device, comprising:

[0010] A reference light source, used to generate a reference light signal;

[0011] a coupler for coupling the input optical signal to be analyzed and the reference optical signal into a combined optical signal;

[0012] a reflective cavity comprising a cavity and a movable reflector disposed vertically in the cavity, wherein the reflective cavity is disposed on the rear side of the coupler to receive a combined optical signal and direct the combined optical signal vertically onto the reflective mirror; the reflective mirror is moved so that the combined optical signal input into the reflective cavity interferes with a light signal reflected by the reflective mirror, and a combined optical interference signal is output;

[0013] a circulator, disposed between the coupler and the reflective cavity, for isolating the combined optical signal from the combined optical interference signal returned via the reflective cavity, and outputting the combined optical interference signal to the first optical filter and the second optical filter;

[0014] The first optical filter is used to filter out the reference light interference signal in the combined light interference signal to obtain the input light interference signal;

[0015] The second optical filter is used to filter out the input light interference signal in the combined light interference signal to obtain a reference light interference signal;

[0016] a first optical signal detection unit, which collects an input optical signal to detect a total power of the input optical signal;

[0017] a second optical signal detection unit, connected to the first optical filter, for detecting the power of the input optical interference signal;

[0018] a third optical signal detection unit, connected to the second optical filter, for detecting the power of the reference light interference signal;

[0019] The CPU is used to control the movement of the reflector in the reflective cavity, obtain the total power of the input optical signal, the power of the input optical interference signal, and the power of the reference optical interference signal, and calculate the wavelength of the input optical signal and the power corresponding to the wavelength based on the known reference wavelength of the reference optical signal.

[0020] Preferably, an isolator is provided on the front side of the coupler, and the input optical signal enters the coupler via the isolator.

[0021] Preferably, a collimator is provided at the entrance of the reflective cavity, and the collimator is used to transmit the combined optical signal to the reflective cavity. The end face where the collimator is connected to the optical path interface of the reflective cavity is the interference point between the combined optical signal and the reflected optical signal of the combined optical signal.

[0022] Preferably, the first optical signal detection unit includes a first photodiode and a first analog-to-digital converter connected in sequence, the first analog-to-digital converter is connected to the CPU, the first photodiode collects the input optical signal, obtains the total power of the input optical signal and converts it into a digital signal by the first analog-to-digital converter and sends it to the CPU.

[0023] Preferably, the second optical signal detection unit includes a second photodiode and a second analog-to-digital converter connected in sequence, the second analog-to-digital converter is connected to the CPU, the second photodiode collects the input optical interference signal, obtains the power of the input optical interference signal and converts it into a digital signal by the second analog-to-digital converter and sends it to the CPU.

[0024] Preferably, the third optical signal detection unit includes a third photodiode and a third analog-to-digital converter connected in sequence, the third analog-to-digital converter is connected to the CPU, the third photodiode collects the reference light interference signal, obtains the power of the reference light interference signal and converts it into a digital signal by the third analog-to-digital converter and sends it to the CPU.

[0025] Based on the same concept, the present invention also provides an analysis method of the above-mentioned interference spectrum analysis device, comprising the following steps:

[0026] The CPU obtains the total power of the input optical signal through the first optical signal detection unit;

[0027] Turn on the reference light source, and the CPU controls the reflector in the reflective cavity to move at the set speed;

[0028] While the reflector moves, the CPU obtains the power of the reference light interference signal through the third light signal detection unit; the CPU obtains the power of the input light interference signal through the second light signal detection unit;

[0029] Performing Fourier transform on the power of the reference light interference signal and then solving for the center point to obtain the interference frequency of the reference light signal;

[0030] Performing Fourier transform on the power of the input optical interference signal to obtain the proportional relationship between the interference frequency of each frequency point of the input optical signal and the amplitude of each frequency point; the proportional relationship between the amplitude of each frequency point of the input optical signal is the proportional relationship between the power of each frequency point of the input optical signal;

[0031] The wavelength of the input optical signal corresponding to each frequency point is calculated based on the relationship between the wavelength and interference frequency of the input optical signal and the wavelength and interference frequency of the reference optical signal;

[0032] According to the fact that the total power of the input optical signal is equal to the sum of the powers of the various frequency points of the input optical signal, the power of the various frequency points of the input optical signal is obtained by calculation.

[0033] Preferably, the wavelength of the input optical signal and the interference frequency of the input optical signal and the wavelength of the reference optical signal and the interference frequency of the reference optical signal satisfy the following formula:

[0034]

[0035] in, is the wavelength of the input optical signal; F in is the interference frequency of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

[0036] Preferably, the wavelength of the input optical signal corresponding to each frequency point is calculated using the following formula:

[0037]

[0038] Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, is the wavelength of the nth frequency point of the input optical signal; F in-n is the interference frequency of the nth frequency point of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

[0039] Preferably, the power of each frequency point of the input optical signal is calculated by the following formula:

[0040]

[0041] P in-0 :P in-1 :...:P in-nm =FFT_0:FFT_1:...:FFT_n

[0042] Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, P total is the total power of the input optical signal; P in-n is the power of the nth frequency point of the input optical signal; FFT_0:FFT_1:...:FFT_n are the proportional relationship between the amplitudes of each frequency point obtained by Fourier transforming the power signal of the input optical interference signal.

[0043] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0044] An embodiment of the present invention provides an interference-type spectral analysis device and analysis method, which introduce a reference light source and use digital signal processing methods to compare and analyze the interference signal between a known reference light signal and an input light signal to be analyzed in the same optical path. The spectral component of the input light signal is deduced through the known reference light signal, and the control requirement for the cavity length with nm-level accuracy is converted to a requirement for the wavelength stability of the reference light source. While reducing the control accuracy requirement of the interference-type spectral analysis device for the reflective cavity, the accuracy of the spectral analysis is improved to the 0.01nm level, the same as that of the reference light source, thereby improving the performance of the interference spectrometer while reducing the system cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention, not all embodiments. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0046] Figure 1 A schematic structural diagram of an interference spectrum analysis device provided in one embodiment of the present invention;

[0047] Figure 2 This is a flow chart of an analysis method using an interference spectrum analysis device according to an embodiment of the present invention.

[0048] In the picture:

[0049] 1-reference light source; 2-isolator; 3-coupler; 4-reflection cavity; 41-cavity; 42-reflector; 43-collimator; 5-circulator; 6-first optical filter; 7-second optical filter; 8-first optical signal detection unit; 81-first photodiode; 82-first analog-to-digital converter; 9-second optical signal detection unit; 91-second photodiode; 92-second analog-to-digital converter; 10-third optical signal detection unit; 101-third photodiode; 102-third analog-to-digital converter; 11-CPU. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] The technical solution of the present invention is described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0052] Based on the problems existing in the prior art, an embodiment of the present invention provides an interference-type spectral analysis device and analysis method, which introduces a reference light source. By comparing and analyzing a known reference light signal and an input light signal in the same optical path, the spectral composition of the input light signal is inferred, thereby reducing the dependence of the interference-type spectral analysis device on a large stroke and high-precision cavity control system.

[0053] Figure 1 A schematic structural diagram of an interference spectrum analysis device provided in one embodiment of the present invention; Figure 2 This is a flow chart of an analysis method using an interference spectrum analysis device according to an embodiment of the present invention.

[0054] See now Figure 1 , an embodiment of the present invention provides an interference spectrum analysis device, comprising:

[0055] A reference light source 1, for generating a reference light signal;

[0056] a coupler 3, for coupling the input optical signal to be analyzed and the reference optical signal into a combined optical signal;

[0057] The reflective cavity 4 includes a cavity 41 and a movable reflector 42 vertically disposed in the cavity 41. The reflective cavity 4 is disposed on the rear side of the coupler 3 to receive the combined optical signal and direct the combined optical signal vertically onto the reflector 4. The reflector 4 is movable so that the combined optical signal input into the reflective cavity 4 interferes with the optical signal reflected by the reflector 42, thereby outputting a combined optical interference signal.

[0058] The circulator 5 is provided between the coupler 3 and the reflective cavity 4, and is used to isolate the combined optical signal from the combined optical interference signal returned by the reflective cavity 4, and output the combined optical interference signal to the first optical filter 6 and the second optical filter 7;

[0059] a first optical filter 6, for filtering out the reference light interference signal in the combined light interference signal to obtain an input light interference signal;

[0060] a second optical filter 7, for filtering out the input light interference signal from the combined light interference signal to obtain a reference light interference signal;

[0061] The first optical signal detection unit 8 collects the input optical signal to detect the total power of the input optical signal;

[0062] a second optical signal detection unit 9, connected to the first optical filter 6, for detecting the power of the input optical interference signal;

[0063] a third optical signal detection unit 10, connected to the second optical filter 7, for detecting the power of the reference light interference signal;

[0064] The CPU (Central Processing Unit) 11 is used to control the movement of the reflector 42 in the reflective cavity 4, obtain the total power of the input optical signal, the power of the input optical interference signal, and the power of the reference optical interference signal, and calculate the wavelength of the input optical signal and the power corresponding to the wavelength based on the known reference wavelength of the reference optical signal.

[0065] Specifically, reference light source 1 utilizes a high-precision laser source that emits wavelength-stable laser light, which serves as the reference light. Advances in laser technology have made it possible to control the temperature variation of a typical DFB (Distributed Feedback Laser) laser to within 0.03°C using a low-cost two-stage temperature control loop, stabilizing the wavelength of the laser light emitted by the DFB laser to within 0.001nm.

[0066] In some embodiments, an isolator 2 is provided in front of the coupler 3 , and the input optical signal enters the coupler 3 via the isolator 2 , preventing the reference optical signal of the reference light source 1 from crosstalking into the input optical path and interfering with the first optical signal detection unit 8 .

[0067] Specifically, the circulator 5 isolates the combined optical signal from the combined optical interference signal returned via the reflective cavity 4 , thereby preventing the returned optical signal from interfering with the reference light source 1 and causing instability of the reference light source 1 .

[0068] Specifically, the wavelength range of the input light is usually 1300nm-1600nm, and the wavelength range of the laser used as the reference light is usually 200nm-600nm. The wavelength difference between the two is very large. The first optical filter 6 and the second optical filter 7 implement optical filtering according to the wavelength range.

[0069] In some embodiments, a collimator 43 is provided at the entrance of the reflective cavity 4, and the collimator 43 is used to transmit the combined optical signal to the reflective cavity 4. The end face where the collimator 43 is connected to the optical path interface of the reflective cavity 4 is the interference point between the combined optical signal and the reflected optical signal of the combined optical signal.

[0070] In some embodiments, the first optical signal detection unit 8 includes a first photodiode 81 and a first analog-to-digital converter 82 connected in sequence. The first analog-to-digital converter 82 is connected to the CPU 11. The first photodiode 81 collects the input optical signal, obtains the total power of the input optical signal and converts it into a digital signal by the first analog-to-digital converter 82 and sends it to the CPU 11.

[0071] In some embodiments, the second optical signal detection unit 9 includes a second photodiode 91 and a second analog-to-digital converter 92 connected in sequence, the second analog-to-digital converter 92 is connected to the CPU 11, the second photodiode 91 collects the input optical interference signal, obtains the power of the input optical interference signal and converts it into a digital signal by the second analog-to-digital converter 92 and sends it to the CPU 11.

[0072] In some embodiments, the third optical signal detection unit 10 includes a third photodiode 101 and a third analog-to-digital converter 102 connected in sequence, the third analog-to-digital converter 102 is connected to the CPU 11, the third photodiode 101 collects the reference light interference signal, obtains the power of the reference light interference signal and converts it into a digital signal by the third analog-to-digital converter 102 and sends it to the CPU 11.

[0073] See also Figure 2 The present invention also provides an analysis method of an interference spectrum analysis device, comprising the following steps:

[0074] S1: The CPU 11 obtains the total power of the input optical signal through the first optical signal detection unit 8;

[0075] S2: Turn on the reference light source 1, and the CPU 11 controls the reflector 42 in the reflective cavity 4 to move at a set speed;

[0076] S3: While the reflector 42 is moving, the CPU 11 obtains the power of the reference light interference signal through the third light signal detection unit 10; the CPU 11 obtains the power of the input light interference signal through the second light signal detection unit 9;

[0077] S4: Performing Fourier transform on the power of the reference light interference signal and then solving for the center point to obtain the interference frequency of the reference light signal;

[0078] S5: Performing Fourier transform on the power of the input optical interference signal to obtain a proportional relationship between the interference frequency of each frequency point of the input optical signal and the amplitude of each frequency point; the proportional relationship between the amplitude of each frequency point of the input optical signal is the proportional relationship between the power of each frequency point of the input optical signal;

[0079] S6: calculating the wavelength of the input optical signal corresponding to each frequency point based on the relationship between the wavelength and interference frequency of the input optical signal and the wavelength and interference frequency of the reference optical signal;

[0080] S7: According to the total power of the input optical signal being equal to the sum of the powers of the input optical signal at each frequency point, the power of each frequency point of the input optical signal is calculated.

[0081] Specifically, in step S2, the CPU 11 controls the speed of the reflector 42 in the reflective cavity 4 to move at Lnm / S; during the process of the length of the reference light in the cavity 41 changing by Lnm, the number of interference superposition or decomposition of the reference light and its reflected light is is the wavelength of the reference light, the interference frequency of the reference light is expressed as:

[0082]

[0083] Assume that the wavelength of the input optical signal is Then, during the process of the input light changing the length of the cavity 41 by Lnm, the number of times the input light and its reflected light interfere, superpose or cancel each other is Then the interference frequency of the input light is expressed as:

[0084]

[0085] Then the wavelength of the input optical signal and the interference frequency of the input optical signal and the wavelength of the reference optical signal and the interference frequency of the reference optical signal satisfy the following formula:

[0086]

[0087] in, is the wavelength of the input optical signal; F in is the interference frequency of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

[0088] By analogy with single-wavelength signals, when the input optical signal is a broadband signal, the interference signal of the input light is subjected to Fourier transform analysis, and the wavelength of the input optical signal corresponding to each frequency point is calculated using the following formula:

[0089]

[0090] Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, is the wavelength of the nth frequency point of the input optical signal; F in-n is the interference frequency of the nth frequency point of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

[0091] In some embodiments, the power of each frequency point of the input optical signal is calculated by the following formula:

[0092] P total =∑P in-n

[0093] P in-0 :P in-1 :...:P in-n =FFT_0:FFT_1:...:FFT_n

[0094] Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, P total is the total power of the input optical signal; P in-n is the power of the nth frequency point of the input optical signal; FFT_0:FFT_1:...:FFT_n are the proportional relationship between the amplitudes of each frequency point obtained by Fourier transforming the power signal of the input optical interference signal.

[0095] Compared with the existing technology, the frequency of the input light signal corresponding to each frequency point is obtained by Fourier transform analysis of the interference signal of the input light, and then the frequency of the input light signal corresponding to each frequency point is obtained according to the By calculating the wavelength of the input light signal corresponding to each frequency point, the present invention converts the control requirement of the cavity 41 length with nm-level accuracy into the wavelength stability requirement of the reference light source 1, thereby reducing the control accuracy requirement of the reflective cavity of the interference spectrum analyzer.

[0096] In summary, an interference-type spectral analysis device and analysis method provided by an embodiment of the present invention introduce a reference light source 1, and use a digital signal processing method to compare and analyze the interference signal between a known reference light signal and an input light signal to be analyzed in the same optical path. The spectral component of the input light signal is calculated through the known reference light signal, and the control requirement for the length of the cavity 41 with nm-level accuracy is converted to the wavelength stability requirement for the reference light source 1. While reducing the control accuracy requirement of the interference-type spectral analysis device for the reflective cavity, the accuracy of the spectral analysis is improved to the same 0.01nm level as the reference light source 1, thereby improving the performance of the interference spectrometer while reducing the system cost.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An interference spectrum analysis device, characterized in that include: A reference light source, used to generate a reference light signal; a coupler for coupling the input optical signal to be analyzed and the reference optical signal into a combined optical signal; a reflective cavity comprising a cavity and a movable reflector disposed vertically in the cavity, wherein the reflective cavity is disposed on the rear side of the coupler to receive a combined optical signal and direct the combined optical signal vertically onto the reflective mirror; the reflective mirror is moved so that the combined optical signal input into the reflective cavity interferes with a light signal reflected by the reflective mirror, and a combined optical interference signal is output; a circulator, disposed between the coupler and the reflective cavity, for isolating the combined optical signal from the combined optical interference signal returned via the reflective cavity, and outputting the combined optical interference signal to the first optical filter and the second optical filter; The first optical filter is used to filter out the reference light interference signal in the combined light interference signal to obtain the input light interference signal; the second optical filter is used to filter out the input light interference signal in the combined light interference signal to obtain the reference light interference signal; a first optical signal detection unit, which collects an input optical signal to detect a total power of the input optical signal; a second optical signal detection unit, connected to the first optical filter, for detecting the power of the input optical interference signal; a third optical signal detection unit, connected to the second optical filter, for detecting the power of the reference light interference signal; The CPU is used to control the movement of the reflector in the reflective cavity, obtain the total power of the input optical signal, the power of the input optical interference signal, and the power of the reference optical interference signal, and calculate the wavelength of the input optical signal and the power corresponding to the wavelength based on the known reference wavelength of the reference optical signal.

2. The interference spectrum analyzer according to claim 1, wherein An isolator is provided on the front side of the coupler, and the input optical signal enters the coupler via the isolator.

3. The interference spectrum analyzer according to claim 1, wherein A collimator is provided at the entrance of the reflective cavity, and is used to transmit the combined optical signal to the reflective cavity. The end face where the collimator is connected to the optical path interface of the reflective cavity is the interference point between the combined optical signal and the reflected optical signal of the combined optical signal.

4. The interference spectrum analyzer according to claim 1, wherein The first optical signal detection unit includes a first photodiode and a first analog-to-digital converter connected in sequence. The first analog-to-digital converter is connected to the CPU. The first photodiode collects the input optical signal, obtains the total power of the input optical signal, and converts it into a digital signal by the first analog-to-digital converter and sends it to the CPU.

5. The interference spectrum analyzer according to claim 1, wherein The second optical signal detection unit includes a second photodiode and a second analog-to-digital converter connected in sequence, the second analog-to-digital converter is connected to the CPU, the second photodiode collects the input optical interference signal, obtains the power of the input optical interference signal and converts it into a digital signal by the second analog-to-digital converter and sends it to the CPU.

6. The interference spectrum analyzer according to claim 1, wherein The third optical signal detection unit includes a third photodiode and a third analog-to-digital converter connected in sequence. The third analog-to-digital converter is connected to the CPU. The third photodiode collects a reference optical interference signal, obtains the power of the reference optical interference signal, and converts the power into a digital signal by the third analog-to-digital converter and sends it to the CPU.

7. An analysis method using the interference spectrum analysis device according to any one of claims 1 to 6, characterized in that: The steps include: The CPU obtains the total power of the input optical signal through the first optical signal detection unit; Turn on the reference light source, and the CPU controls the reflector in the reflective cavity to move at the set speed; While the reflector moves, the CPU obtains the power of the reference light interference signal through the third light signal detection unit; the CPU obtains the power of the input light interference signal through the second light signal detection unit; Performing Fourier transform on the power of the reference light interference signal and then solving for the center point to obtain the interference frequency of the reference light signal; Performing Fourier transform on the power of the input optical interference signal to obtain the proportional relationship between the interference frequency of each frequency point of the input optical signal and the amplitude of each frequency point; the proportional relationship between the amplitude of each frequency point of the input optical signal is the proportional relationship between the power of each frequency point of the input optical signal; The wavelength of the input optical signal corresponding to each frequency point is calculated based on the relationship between the wavelength and interference frequency of the input optical signal and the wavelength and interference frequency of the reference optical signal; According to the fact that the total power of the input optical signal is equal to the sum of the powers of the various frequency points of the input optical signal, the power of the various frequency points of the input optical signal is obtained by calculation.

8. The analysis method according to claim 7, characterized in that The wavelength of the input optical signal and the interference frequency of the input optical signal and the wavelength of the reference optical signal and the interference frequency of the reference optical signal satisfy the following formula: in, is the wavelength of the input optical signal; F in is the interference frequency of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

9. The analysis method according to claim 8, characterized in that The wavelength of the input optical signal corresponding to each frequency point is calculated using the following formula: Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, is the wavelength of the nth frequency point of the input optical signal; F in-n is the interference frequency of the nth frequency point of the input optical signal; is the wavelength of the reference optical signal; F ref is the interference frequency of the reference optical signal.

10. The analysis method according to claim 7, characterized in that The power of each frequency point of the input optical signal is calculated by the following formula: P total =∑P in-n P in-0 :P in-1 :...:P in-n =FFT_0:FFT_1:...:FFT_n Where n = 0, 1, 2... (1 / 2) f s , f s is the sampling frequency, P total is the total power of the input optical signal; P in-n is the power of the nth frequency point of the input optical signal; FFT_0:FFT_1:...:FFT_n are the proportional relationship between the amplitudes of each frequency point obtained by Fourier transforming the power signal of the input optical interference signal.

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