A high-precision wide-spectrum laser wavelength measurement device and method

Abstract

The application discloses a high-precision wide-spectrum laser wavelength measuring device, comprising a frequency-stabilized reference laser, a laser to be measured, an optical comb generator, an optical radio frequency signal system and a beat frequency signal measuring system, and discloses a high-precision wide-spectrum laser wavelength measuring method, wherein the reference laser outputted by the reference laser and the laser to be measured outputted by the laser to be measured are combined with the optical comb to generate a first beat frequency signal and a second beat frequency signal, the optical radio frequency signal system generates a radio frequency reference signal based on the radio frequency signal outputted by the optical comb generator and the first beat frequency signal, the frequency ratio measuring system takes the radio frequency reference signal as a reference, and calculates the frequency of the laser to be measured relative to the reference laser based on the second beat frequency signal and the first beat frequency signal. The application can efficiently realize laser frequency measurement at the level of Hz to sub-Hz.

Description

Technical Field

[0001] This invention relates to the field of precision spectroscopy, specifically to a high-precision broadband laser wavelength measurement device and a high-precision broadband laser wavelength measurement method, which are mainly used in scientific fields such as laser frequency measurement, laser wavelength tracing, reproduction of length units, and precise atomic and molecular spectral measurement. Background Technology

[0002] Precise measurement of laser frequency, or wavelength, is of great significance in scientific research and production. Accurate laser frequency determination is an indispensable step in precision spectroscopy and length tracing. Traditional precise laser wavelength measurement involves beating the laser to be measured against a reference laser. This method severely limits the measurable laser wavelength range. Since the invention of the optical frequency comb, locking the comb to a microwave atomic clock has enabled the measurement of a wide range of laser wavelengths traced back to a microwave reference. However, both methods have certain limitations, the main problems of which are as follows:

[0003] 1. Direct beat frequency measurement with a reference laser has the drawback of a small measurable wavelength range;

[0004] 2. The measurement method that traces directly to the microwave reference through an optical comb has the disadvantages of low short-term stability of the microwave reference and excessively long measurement time for high-precision measurements. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a high-precision broadband laser wavelength measurement device and a high-precision broadband laser wavelength measurement method. By utilizing an optical comb, the optical frequency ratio measurement method replaces the direct laser beat frequency method or the method of directly tracing the source to a microwave clock via the optical comb, thereby achieving rapid, high-precision, and wide-wavelength range laser frequency (wavelength) measurement and tracing.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A high-precision broadband laser wavelength measurement device includes a frequency-stabilized reference laser. The reference laser output from the reference laser is combined with the first beam split from the optical comb output from the optical comb generator to generate a first beat frequency signal. The laser under test output from the laser under test is combined with the second beam splitter output from the optical comb generator to generate a second beat frequency signal. ,

[0008] Second beat frequency signal First beat frequency signal And the frequency output by the optical comb generator is equal to the carrier bias phase frequency of the optical comb. All radio frequency signals are sent to the frequency ratio measurement system;

[0009] At the same time, the first beat frequency signal The frequency output by the optical comb generator is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the optically generated radio frequency signal system, which then generates a radio frequency reference signal. And send it to the frequency ratio measurement system;

[0010] Frequency ratio measurement system uses radio frequency reference signal For reference, and in conjunction with the second beat frequency signal and the first beat frequency signal The frequency of the test laser relative to the reference laser is calculated.

[0011] As described above, the frequency ratio measurement system includes, in sequence, a frequency difference extraction module, a multi-channel frequency meter, and a frequency ratio calculation system;

[0012] The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb Radio frequency signal extraction of carrier bias phase frequency of optical comb ;

[0013] The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb The reference laser and optical comb were obtained. Frequency difference between repetition frequencies Record the first frequency difference ;

[0014] The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb The laser to be tested and the optical comb were obtained. Frequency difference between repetition frequencies , denoted as the second frequency difference ;

[0015] Multi-channel frequency meter receives first frequency difference Second frequency difference and the radio frequency reference signal generated by the photoelectric radio frequency signal system And measure the first frequency difference relative to the frequency of the radio frequency reference signal The ratio of the two frequencies is used to obtain the first frequency ratio. ; Measure the second frequency difference relative to the frequency of the radio frequency reference signal The ratio of the two frequencies is used to obtain the second frequency ratio. ;

[0016] First frequency ratio The ratio of the second frequency The signal is sent to a frequency ratio calculation system to calculate the frequency of the test laser relative to the reference laser.

[0017] ,

[0018] in, The frequency of the test laser is relative to the reference laser. For reference laser frequency, For reference, when the laser and the optical comb beat at the same frequency, the corresponding optical frequency longitudinal mode number of the optical comb is used. The optical frequency longitudinal mode number of the optical comb corresponding to the beat frequency of the laser under test and the optical comb; the frequency of the radio frequency reference signal. , This is a preset frequency ratio;

[0019] wavelength of the laser under test relative to the reference laser , It represents the speed of light.

[0020] As described above, the photoelectric radio frequency signal system includes a beat frequency signal extraction module, a first digital synthesizer, a second digital synthesizer, a second radio frequency adder, and a radio frequency subtractor.

[0021] The beat frequency signal extraction module extracts the first beat frequency signal. Converted into an electrical signal, and with a frequency equal to the carrier bias phase frequency of the optical comb. The radio frequency signals are fed into a first radio frequency adder to add their frequencies, and the output frequency is equal to the first frequency difference. Radio frequency signals;

[0022] The frequency output of the first RF frequency adder is equal to the first frequency difference. The radio frequency signal is divided into a first frequency difference first component signal and a first frequency difference second component signal;

[0023] The first frequency difference, the first component signal, and the frequency output by the optical comb generator are equal to the repetition frequency of the optical comb. The radio frequency signals are added together by a second radio frequency adder, and the output frequency is... The radio frequency signal has a frequency of The radio frequency signal is frequency-reduced to [value] by the first digital synthesizer. ;

[0024] The first frequency difference second component signal is frequency-reduced by the second digital synthesizer. The frequency output of the first digital synthesizer is The radio frequency signal and the output of the second digital synthesizer are at a frequency of The radio frequency signal is subtracted from the radio frequency signal using a radio frequency frequency subtractor to obtain the radio frequency reference signal. The frequency of the radio frequency reference signal ;

[0025] The first radio frequency adder and the second radio frequency adder each include a corresponding mixer and a sum-frequency extraction filter in sequence.

[0026] The radio frequency subtractor includes a corresponding mixer and a difference frequency extraction filter.

[0027] The radio frequency reference signal generated by the photoelectric radio frequency signal system as described above It also inputs a phase-locked system, while referencing a standard laser frequency source output frequency of [missing value]. The clock signal is sent to the phase-locked system; the frequency of the radio frequency reference signal. The frequency of the radio frequency reference signal is locked to a reference laser frequency standard source via a phase-locking system. The frequency relationship between the reference laser frequency and the standard source is as follows: ,in, The parameter is the ratio of the preset frequency of the radio frequency reference signal to the frequency of the reference laser frequency standard source. With clock signal frequency The relationship is: The phase-locked system outputs a feedback control signal to the frequency tuning port of the reference laser.

[0028] As mentioned above, the reference laser frequency standard source is a microwave clock or an optical clock.

[0029] The radio frequency reference signal generated by the photoelectric radio frequency signal system as described above The clock signals output from the reference laser frequency standard source are respectively input to the corresponding frequency meters, and the radio frequency reference signals generated by the photoelectric radio frequency signal system are read. A feedback control signal is obtained relative to the frequency value of the output clock signal of the reference laser frequency standard source, and the feedback control signal is output to the frequency tuning port of the reference laser.

[0030] As described above, the photoelectric radio frequency signal system is based on the first beat frequency signal. By locking the phase of the optical comb to the reference laser, the precise repetition frequency of the optical comb can be obtained. , For reference laser frequency, The beat frequency of the first beat frequency signal; based on the acquired precise repetition frequency of the optical comb. An RF reference signal is generated by a third digital synthesizer. and make the frequency of the radio frequency reference signal satisfy , This is a preset frequency ratio;

[0031] At the same time, the first beat frequency signal With frequency equal to the carrier bias phase frequency of the optical comb The radio frequency signals are added together by a third radio frequency adder, and the output frequency is equal to the first frequency difference. radio frequency signals, The frequency output of the third radio frequency adder is equal to the first frequency difference. The radio frequency signal is phase-locked to a preset radio frequency frequency of the radio frequency reference source; wherein, the third radio frequency adder includes a corresponding mixer and a sum-frequency extraction filter in sequence;

[0032] The frequency ratio measurement system includes a frequency difference extraction module, an RF reference signal correction module, a multi-channel frequency meter, and a frequency ratio calculation system;

[0033] The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb Radio frequency signal extraction of carrier bias phase frequency of optical comb ;

[0034] The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb The reference laser and optical comb were obtained. Frequency difference between repetition frequencies Record the first frequency difference ;

[0035] The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb The laser to be tested and the optical comb were obtained. Frequency difference between repetition frequencies , denoted as the second frequency difference ;

[0036] The radio frequency reference signal correction module receives the radio frequency reference signal. Extracting the frequency of the radio frequency reference signal ; Utilizing the first frequency difference Frequency of radio frequency reference signal Mathematical corrections are performed to determine the frequency of the corrected radio frequency reference signal. ;

[0037] Multi-channel frequency meter receives first frequency difference Second frequency difference and the frequency of the corrected radio frequency reference signal Measure the first frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the first frequency ratio. ; Measure the second frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the second frequency ratio. ;

[0038] First frequency ratio The ratio of the second frequency The signal is sent to a frequency ratio calculation system to calculate the frequency of the test laser relative to the reference laser.

[0039] ,

[0040] in, The frequency of the test laser is relative to the reference laser. For reference laser frequency, For reference, when the laser and the optical comb beat at the same frequency, the corresponding optical frequency longitudinal mode number of the optical comb is used. The optical frequency longitudinal mode number of the optical comb when the laser under test beats the optical comb;

[0041] wavelength of the laser under test relative to the reference laser , It represents the speed of light.

[0042] A high-precision broadband laser wavelength measurement method, utilizing the high-precision broadband laser wavelength measurement device described above, includes the following steps:

[0043] Step 1: Build a high-precision broadband laser wavelength measurement device;

[0044] Step 2: The reference laser output from the reference laser is combined with the first beam split from the optical comb output from the optical comb generator to generate the first beat frequency signal. The laser under test output from the laser under test is combined with the second beam splitter output from the optical comb generator to generate a second beat frequency signal. Second beat frequency signal First beat frequency signal And the frequency output by the optical comb generator is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the frequency ratio measurement system;

[0045] At the same time, the first beat frequency signal The frequency output by the optical comb generator is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the optically generated radio frequency signal system;

[0046] Step 3: The photoelectric radio frequency signal system generates a radio frequency reference signal. And send it to the frequency ratio measurement system;

[0047] Step 4: The frequency ratio measurement system uses an RF reference signal. For reference, and based on the second beat frequency signal and the first beat frequency signal Calculate the frequency of the test laser relative to the reference laser. The wavelength of the laser to be tested relative to the reference laser , It represents the speed of light.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] The reference laser, through a radio frequency reference signal generated by an optically generated radio frequency signal system, is kept phase-locked with a microwave atomic clock for an extended period. This results in a highly definite frequency ratio between the reference laser and the microwave atomic clock, and the ultra-stable laser itself exhibits extremely high short- and medium-term frequency stability. Based on this, a method for measuring laser frequency using the optical-frequency ratio is employed instead of the simple optical comb-to-microwave clock method. This approach, while ensuring the measurement wavelength range, significantly reduces the laser frequency measurement time, enabling high-precision laser frequency measurement in a short time. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the core structure of the present invention;

[0051] Figure 2 This is a schematic diagram of the main structure of the frequency ratio measurement system of the present invention; wherein, The first frequency difference, The second frequency difference, The frequency of the radio frequency reference signal;

[0052] Figure 3This is a schematic diagram of the main structure of the optically generated radio frequency signal system of the present invention; DDS1 is the repetition frequency of the optical comb, DDS2 is the first digital synthesizer, and DDS2 is the second digital synthesizer. The frequency of the first beat frequency signal The carrier bias phase frequency of the optical comb;

[0053] In the figure, 1-reference laser; 2-laser under test; 3-optical comb generator; 4-optical radio frequency signal system; 41-first digital synthesizer; 42-second digital synthesizer; 43-second radio frequency adder; 44-radio frequency subtractor; 45-first radio frequency adder; 5-frequency ratio measurement system; 51-multi-channel frequency meter; 52-frequency ratio calculation system; 6-reference laser frequency standard source; 7-phase locking system. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0055] To make the implementation objectives, technical solutions, and advantages of this invention clearer, the implementation details of the technical solution of this invention will be described in detail below with reference to the accompanying drawings.

[0056] Example 1:

[0057] A high-precision broadband laser wavelength measurement device, such as Figure 1 As shown, it includes a frequency-stabilized reference laser 1, a laser under test 2, an optical comb generator 3, an optically generated radio frequency signal system 4, and a frequency ratio measurement system 5.

[0058] The reference laser output from reference laser 1 is combined with the first beam splitter of the optical frequency comb (or simply optical comb) output from optical comb generator 3 to generate the first beat frequency signal. The laser under test output from laser under test 2 is combined with the second beam splitter output from optical comb generator 3 to generate a second beat frequency signal. Second beat frequency signal First beat frequency signal And the frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. All radio frequency signals are sent to the frequency ratio measurement system 5; simultaneously, the first beat frequency signal The frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. The frequency of the radio frequency signal output by the optical comb generator 3 is equal to the repetition frequency of the optical comb. The radio frequency signal is sent to the photoelectric radio frequency signal system 4, and the photoelectric radio frequency signal system 4 generates a radio frequency reference signal. And sent to frequency ratio measurement system 5; frequency ratio measurement system 5 uses radio frequency reference signal For reference, and based on the second beat frequency signal and the first beat frequency signal The frequency of the test laser relative to the reference laser is calculated.

[0059] Among them, optical comb spectrum , The carrier bias phase frequency of the optical comb. The repetition frequency of the optical comb. This refers to the optical frequency longitudinal mode number of the optical comb (the comb tooth number).

[0060] The reference laser output by the reference laser 1 is an ultra-stable laser with high frequency stability. The beat frequency of the reference laser and the optical comb makes the reference laser frequency... With optical comb spectrum To establish a connection, that is ,in , It is a reference to the first laser and optical comb. The beat frequency of each longitudinal mode is denoted as the beat frequency of the first beat frequency signal. ; It is based on lasers and optical combs. The frequency difference between two repetition frequencies is denoted as the first frequency difference. First frequency difference The beat frequency of the first beat frequency signal The carrier bias phase frequency of the optical comb Obtained. The radio frequency reference signal generated by the photoelectric radio frequency signal system 4. The frequency of the radio frequency reference signal With reference laser frequency Proportional: ,in This is a preset frequency ratio.

[0061] The frequency of the laser under test and the beat frequency of the optical comb result in the frequency of the laser under test. With optical comb spectrum To establish a connection, that is ,in ,in, This is the first test of the laser and optical comb. The beat frequency of each longitudinal mode is denoted as the beat frequency of the second beat frequency signal. ; It is the laser to be tested and the optical comb. The frequency difference between two repetition frequencies is denoted as the second frequency difference. Second frequency difference The beat frequency of the second beat frequency signal The carrier bias phase frequency of the optical comb get.

[0062] The present invention uses the radio frequency reference signal generated by the photoelectric radio frequency signal system 4 For reference, the first frequency difference is simultaneously measured by the frequency ratio measurement system 5. relative to the frequency of the radio frequency reference signal The ratio, and the second frequency difference relative to the frequency of the radio frequency reference signal The ratio of the two lasers is used to calculate the frequency of the laser under test relative to the reference laser. ,in For reference, when the laser and the optical comb beat at the same frequency, the corresponding optical frequency longitudinal mode number of the optical comb is used. This refers to the longitudinal mode number of the optical comb corresponding to the beat frequency of the laser under test when it beats with the optical comb. Further, the wavelength of the laser under test relative to the reference laser is precisely measured. , It represents the speed of light.

[0063] Furthermore, the frequency ratio measurement system 5 sequentially includes a frequency difference extraction module, a multi-channel frequency meter 51, and a frequency ratio calculation system 52, as follows: Figure 2 As shown:

[0064] The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb Radio frequency signal extraction of carrier bias phase frequency of optical comb ;

[0065] The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb Add them together to get the first frequency difference. ;

[0066] The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb Add them together to get the second frequency difference. ;

[0067] Multi-channel frequency meter 51 receives the first frequency difference Second frequency difference and the radio frequency reference signal generated by the photoelectric radio frequency signal system 4 And measure the first frequency difference relative to the frequency of the radio frequency reference signal The ratio (denoted as the first frequency ratio) ), and the second frequency difference relative to the frequency of the radio frequency reference signal The ratio (denoted as the second frequency ratio) ); the measured second frequency ratio and the first frequency ratio The signal is sent to the frequency ratio calculation system 52, which calculates the frequency of the test laser relative to the reference laser based on the following formula. .

[0068] A detailed description of a photoelectric radio frequency (RF) signal scheme is as follows: the photoelectric RF signal system 4 includes a beat frequency signal extraction module, a first direct digital synthesizer (DDS) 41, a second digital synthesizer 42, a second RF frequency adder 43, an RF frequency subtractor 44, and a first RF frequency adder 45 (e.g., Figure 3 (as shown)

[0069] The beat frequency signal extraction module extracts the first beat frequency signal. Converted into an electrical signal, and with a frequency equal to the carrier bias phase frequency of the optical comb. The radio frequency signals are added together by the first radio frequency adder 45, and the output frequency is equal to the first frequency difference. Radio frequency signals;

[0070] The frequency output of the first RF frequency adder 45 is equal to the first frequency difference. The radio frequency signal is divided into two signals: the first frequency difference first component signal and the first frequency difference second component signal.

[0071] Among them, the frequency of the first frequency difference first component signal and the frequency output by the optical comb generator 3 are equal to the repetition frequency of the optical comb. The radio frequency signals are added together by the second radio frequency adder 43, and the output frequency is . The radio frequency signal has a frequency of The radio frequency signal is frequency-reduced to a specific value by the first digital synthesizer 41. .

[0072] The second frequency difference signal is frequency-reduced by the second digital synthesizer 42. The frequency output of the first digital synthesizer 41 is The radio frequency signal and the output of the second digital synthesizer 42 are at a frequency of The radio frequency signal is subtracted from the radio frequency signal frequency by the radio frequency frequency subtractor 44 to obtain the radio frequency reference signal. The frequency of the radio frequency reference signal .

[0073] The first radio frequency adder 45 and the second radio frequency adder 43 each include a corresponding mixer and a sum frequency extraction filter; the radio frequency subtractor 44 includes a mixer and a difference frequency extraction filter.

[0074] To further trace the frequency of the laser under test back to the microwave atomic clock, the output frequency of the reference laser 1 is controlled by feedback, and the radio frequency reference signal generated by the photoelectric radio frequency signal system 4 is used. The phase-locking system 7 is also input, and the reference laser frequency standard source 6 outputs a frequency of... The clock signal is sent to the phase-locked system 7. In this embodiment, the reference laser frequency standard source 6 is a microwave atomic clock among microwave clocks; the frequency of the radio frequency reference signal... The frequency of the radio frequency reference signal is locked to the reference laser frequency standard source 6 via the phase-locking system 7. The frequency relationship between the reference laser frequency standard source 6 and the standard source 6 is as follows: ,in, The parameter is the ratio of the preset frequency of the radio frequency reference signal to the frequency of the reference laser frequency standard source. With clock signal frequency The relationship is, The phase-locking system 7 outputs a feedback control signal to the frequency tuning port of the reference laser 1. The locked feedback bandwidth is less than one-thousandth of a hertz, ensuring that the reference laser maintains both short-term stability (ultra-stable) and long-term stability (long-term stability) of the reference laser frequency standard source 6. This allows for high-speed, high-precision measurement of the frequency of the laser under test using optical frequency comparison. The frequency of the laser under test relative to the reference laser frequency standard source 6 can be accurately calculated using the ratio of its frequency to that of the reference laser 1. .

[0075] As an alternative implementation, the reference laser can be traced back to an optical clock instead of a microwave clock.

[0076] As another implementation, the reference laser frequency is locked to the reference laser frequency standard source 6. A high-precision frequency locking method can be used instead of the phase-locked method, that is, the radio frequency reference signal generated by the photoelectric radio frequency signal system 4. The clock signal output from the reference laser frequency standard source 6 is input to the corresponding frequency meter, which reads the radio frequency reference signal generated by the photoelectric radio frequency signal system 4. The frequency value of the output clock signal relative to the reference laser frequency standard source 6 (such as the radio frequency reference signal) The frequency ratio between the clock signal and the radio frequency reference signal. The frequency difference between the clock signal and the reference laser 1 is used to obtain a feedback control signal, which is then output to the frequency tuning port of the reference laser 1, so that the RF reference signal generated by the optical RF signal system 4 is controlled. The frequency is a fixed set value (i.e.) ).

[0077] Example 2

[0078] A high-precision broadband laser wavelength measurement device is used to combine the reference laser output from reference laser 1 with the first beam split from the optical comb output from optical comb generator 3 to generate a first beat frequency signal. The laser under test output from laser under test 2 is combined with the second beam splitter output from optical comb generator 3 to generate a second beat frequency signal. Second beat frequency signal First beat frequency signal And the frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. All radio frequency signals are sent to the frequency ratio measurement system 5; simultaneously, the first beat frequency signal The frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the photoelectric radio frequency signal system 4, and the photoelectric radio frequency signal system 4 generates a radio frequency reference signal. And sent to frequency ratio measurement system 5; frequency ratio measurement system 5 uses radio frequency reference signal For reference, and based on the second beat frequency signal and the first beat frequency signal The frequency of the test laser relative to the reference laser is calculated.

[0079] As another implementation, the optically generated radio frequency signal system 4 can employ other methods, such as the optical comb narrow-locking method, to generate the radio frequency reference signal. That is: the photoelectric radio frequency signal system 4 is based on the first beat frequency signal By locking the phase of the optical comb to the reference laser, the precise repetition frequency of the optical comb can be obtained. Based on the obtained precise repetition frequency of the optical comb A radio frequency reference signal is generated through a third digital synthesizer. and make the frequency of the radio frequency reference signal , This is a preset frequency ratio.

[0080] At the same time, the first beat frequency signal With frequency equal to the carrier bias phase frequency of the optical comb The radio frequency signals are added together by a third radio frequency adder, and the output frequency is equal to the first frequency difference. radio frequency signals, The frequency output of the third radio frequency adder is equal to the first frequency difference. The radio frequency signal is phase-locked to a preset radio frequency frequency of the radio frequency reference source, by making the first frequency difference The external RF reference relationship is accurately determined, thereby enabling the frequency of the RF reference signal to be accurately determined. The frequency is accurately measured relative to the RF reference source; wherein, the third RF frequency adder includes a corresponding mixer and a sum-frequency extraction filter in sequence.

[0081] The frequency ratio measurement system 5 includes a frequency difference extraction module, an RF reference signal correction module, a multi-channel frequency meter 51, and a frequency ratio calculation system 52;

[0082] The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb Radio frequency signal extraction of carrier bias phase frequency of optical comb ;

[0083] The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb The reference laser and optical comb were obtained. Frequency difference between repetition frequencies Record the first frequency difference ;

[0084] The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb The laser to be tested and the optical comb were obtained. Frequency difference between repetition frequencies , denoted as the second frequency difference ;

[0085] The radio frequency reference signal correction module receives the radio frequency reference signal. Extracting the frequency of the radio frequency reference signal ; Utilizing the first frequency difference Frequency of radio frequency reference signal Mathematical corrections are performed to determine the frequency of the corrected radio frequency reference signal. .

[0086] Multi-channel frequency meter 51 receives the first frequency difference Second frequency difference and the frequency of the corrected radio frequency reference signal Measure the first frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the first frequency ratio. ; Measure the second frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the second frequency ratio. ;

[0087] First frequency ratio The ratio of the second frequency The signal is sent to the frequency ratio calculation system 52 to calculate the frequency of the test laser relative to the reference laser.

[0088] ,

[0089] in, The frequency of the test laser is relative to the reference laser. For reference excitation frequency, For reference, when the laser and the optical comb beat at the same frequency, the corresponding optical frequency longitudinal mode number of the optical comb is used. The optical frequency longitudinal mode number of the optical comb corresponding to the beat frequency of the laser under test and the optical comb. .

[0090] Further precise measurement of the wavelength of the laser under test relative to the reference laser. , It represents the speed of light.

[0091] Example 3

[0092] A high-precision broadband laser wavelength measurement method, utilizing the high-precision broadband laser wavelength measurement device described in Example 1, includes the following steps:

[0093] Step 1: Build a high-precision broadband laser wavelength measurement device;

[0094] Step 2: The reference laser output from reference laser 1 is combined with the first beam split from the optical comb output from optical comb generator 3 to generate the first beat frequency signal. The laser under test output from laser under test 2 is combined with the second beam splitter output from optical comb generator 3 to generate a second beat frequency signal. Second beat frequency signal First beat frequency signal And the frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the frequency ratio measurement system 5;

[0095] At the same time, the first beat frequency signal The frequency output by optical comb generator 3 is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the photogenerated radio frequency signal system 4;

[0096] Step 3: The photoelectric radio frequency signal system 4 generates a radio frequency reference signal. And send it to the frequency ratio measurement system 5;

[0097] Step 4: Frequency ratio measurement system 5 uses radio frequency reference signal For reference, and based on the second beat frequency signal and the first beat frequency signal The frequency of the test laser relative to the reference laser is calculated. The wavelength of the laser to be tested relative to the reference laser , It represents the speed of light.

[0098] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be defined by the scope of the claims and any improvements made without departing from the principle of the present invention.

Claims

1. A high-precision broadband laser wavelength measurement device, characterized in that, Including a frequency-stabilized reference laser (1), the reference laser output from the reference laser (1) is combined with the first beam split from the optical comb output from the optical comb generator (3) to generate a first beat frequency signal. The laser under test output from the laser under test (2) is combined with the second beam splitter output from the optical comb generator (3) to generate a second beat frequency signal. , Second beat frequency signal First beat frequency signal And the frequency output by the optical comb generator (3) is equal to the carrier bias phase frequency of the optical comb. All radio frequency signals are sent to the frequency ratio measurement system (5); At the same time, the first beat frequency signal The frequency output by the optical comb generator (3) is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the photoelectric radio frequency signal system (4), and the photoelectric radio frequency signal system (4) generates a radio frequency reference signal. And send it to the frequency ratio measurement system (5); The frequency ratio measurement system (5) uses a radio frequency reference signal. For reference, and in conjunction with the second beat frequency signal and the first beat frequency signal The frequency of the test laser relative to the reference laser is calculated; The frequency ratio measurement system (5) and the photoelectric radio frequency signal system (4) are configured as follows: The frequency ratio measurement system (5) includes, in sequence, a frequency difference extraction module, a multi-channel frequency meter (51), and a frequency ratio calculation system (52). The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb. Radio frequency signal extraction of carrier bias phase frequency of optical comb ; The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb The reference laser and optical comb were obtained. Frequency difference between repetition frequencies Record the first frequency difference ; The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb The test laser and the optical comb were obtained. Frequency difference between repetition frequencies , denoted as the second frequency difference ; The multi-channel frequency meter (51) receives the first frequency difference. Second frequency difference and the radio frequency reference signal generated by the photoelectric radio frequency signal system (4) And measure the first frequency difference relative to the frequency of the radio frequency reference signal The ratio of the two frequencies is used to obtain the first frequency ratio. ; Measure the second frequency difference relative to the frequency of the radio frequency reference signal The ratio of the two frequencies is used to obtain the second frequency ratio. ; First frequency ratio The ratio of the second frequency The signal is sent to the frequency ratio calculation system (52) to calculate the frequency of the laser under test relative to the reference laser: ， in, The frequency of the test laser is relative to the reference laser. For reference laser frequency, For reference, when the laser beats the optical comb, the corresponding optical frequency longitudinal mode number of the optical comb is used. The optical frequency longitudinal mode number of the optical comb corresponding to the beat frequency of the laser under test and the optical comb; the frequency of the radio frequency reference signal. , This is a preset frequency ratio; wavelength of the laser under test relative to the reference laser , Represents the speed of light; The photogenerated radio frequency signal system (4) includes a beat frequency signal extraction module, a first digital synthesizer (41), a second digital synthesizer (42), a second radio frequency adder (43), and a radio frequency subtractor (44). The beat frequency signal extraction module extracts the first beat frequency signal. Converted into an electrical signal, and with a frequency equal to the carrier bias phase frequency of the optical comb. The radio frequency signals are fed into a first radio frequency frequency adder (45) to achieve frequency addition, and the output frequency is equal to the first frequency difference. Radio frequency signals; The frequency output of the first RF frequency adder (45) is equal to the first frequency difference. The radio frequency signal is divided into a first frequency difference first component signal and a first frequency difference second component signal; The frequency of the first frequency difference, the first sub-signal, and the output frequency of the comb generator (3) are equal to the repetition frequency of the comb. The radio frequency signals are added together by the second radio frequency frequency adder (43), and the output frequency is . The radio frequency signal has a frequency of The radio frequency signal is frequency-reduced to a specific value by the first digital synthesizer (41). ; The first frequency difference second component signal is frequency-reduced by the second digital synthesizer (42) to [a specific frequency range]. The frequency output of the first digital synthesizer (41) is The radio frequency signal and the output of the second digital synthesizer (42) are at a frequency of The radio frequency signal is subtracted from the radio frequency signal frequency by the radio frequency frequency subtractor (44) to obtain the radio frequency reference signal. The frequency of the radio frequency reference signal ; The first radio frequency adder (45) and the second radio frequency adder (43) each include a corresponding mixer and a sum-frequency extraction filter in sequence. The radio frequency subtractor (44) includes a corresponding mixer and a difference frequency extraction filter in sequence; Alternatively, the frequency ratio measurement system (5) and the photoelectric radio frequency signal system (4) may be configured as follows: The photogenerated radio frequency signal system (4) is based on the first beat frequency signal By locking the phase of the optical comb to the reference laser, the precise repetition frequency of the optical comb can be obtained. , For reference laser frequency, The beat frequency of the first beat frequency signal; based on the acquired precise repetition frequency of the optical comb. An RF reference signal is generated by a third digital synthesizer. and make the frequency of the radio frequency reference signal satisfy , This is a preset frequency ratio; At the same time, the first beat frequency signal The frequency is equal to the carrier bias phase frequency of the optical comb. The radio frequency signals are added together by a third radio frequency adder, and the output frequency is equal to the first frequency difference. radio frequency signals, The frequency output of the third radio frequency adder is equal to the first frequency difference. The radio frequency signal is phase-locked to a preset radio frequency frequency of the radio frequency reference source; wherein, the third radio frequency adder includes a corresponding mixer and a sum-frequency extraction filter in sequence; The frequency ratio measurement system (5) includes a frequency difference extraction module, an RF reference signal correction module, a multi-channel frequency meter (51), and a frequency ratio calculation system (52). The frequency difference extraction module receives the first beat frequency signal. and the second beat frequency signal The first beat frequency signal Second beat frequency signal These are converted into electrical signals, and the beat frequency of the first beat frequency signal is extracted accordingly. and the beat frequency of the second beat frequency signal ; The frequency is equal to the carrier bias phase frequency of the optical comb Radio frequency signal extraction of carrier bias phase frequency of optical comb ; The beat frequency of the first beat frequency signal carrier bias phase frequency of the optical comb The reference laser and optical comb were obtained. Frequency difference between repetition frequencies Record the first frequency difference ; The beat frequency of the second beat frequency signal carrier bias phase frequency of the optical comb The test laser and the optical comb were obtained. Frequency difference between repetition frequencies , denoted as the second frequency difference ; The radio frequency reference signal correction module receives the radio frequency reference signal. Extracting the frequency of the radio frequency reference signal ; Utilizing the first frequency difference Frequency of radio frequency reference signal Mathematical corrections are performed to determine the frequency of the corrected radio frequency reference signal. ; The multi-channel frequency meter (51) receives the first frequency difference. Second frequency difference and the frequency of the corrected radio frequency reference signal Measure the first frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the first frequency ratio. ; Measure the second frequency difference relative to the frequency of the corrected radio frequency reference signal The ratio of the two frequencies is used to obtain the second frequency ratio. ; First frequency ratio The ratio of the second frequency The signal is sent to the frequency ratio calculation system (52) to calculate the frequency of the laser under test relative to the reference laser: ， in, The frequency of the test laser is relative to the reference laser. For reference laser frequency, For reference, when the laser beats the optical comb, the corresponding optical frequency longitudinal mode number of the optical comb is used. The optical frequency longitudinal mode number of the optical comb corresponding to the beat frequency of the laser under test and the optical comb; wavelength of the laser under test relative to the reference laser , It represents the speed of light.

2. The high-precision broadband laser wavelength measurement device according to claim 1, characterized in that, The radio frequency reference signal generated by the photoelectric radio frequency signal system (4) The phase-locked system (7) is also input, and the output frequency of the reference laser frequency standard source (6) is... The clock signal is sent to the phase-locked system (7); the frequency of the radio frequency reference signal The frequency of the radio frequency reference signal is locked to the reference laser frequency standard source (6) by the phase-locking system (7). The frequency relationship between the reference laser frequency standard source (6) and the reference laser frequency standard source (6) is as follows: ,in, The parameter is the ratio of the preset frequency of the radio frequency reference signal to the frequency of the reference laser frequency standard source. With clock signal frequency The relationship is: The phase-locked system (7) outputs a feedback control signal to the frequency tuning port of the reference laser (1).

3. The high-precision broadband laser wavelength measurement device according to claim 2, characterized in that, The reference laser frequency standard source (6) is a microwave clock or an optical clock.

4. The high-precision broadband laser wavelength measurement device according to claim 2, characterized in that, The radio frequency reference signal generated by the photoelectric radio frequency signal system (4) The clock signals output from the reference laser frequency standard source (6) are respectively input to the corresponding frequency meters, and the radio frequency reference signals generated by the photoelectric radio frequency signal system (4) are read. A feedback control signal is obtained relative to the frequency value of the output clock signal of the reference laser frequency standard source (6), and the feedback control signal is output to the frequency tuning port of the reference laser (1).

5. A high-precision broadband laser wavelength measurement method, utilizing the high-precision broadband laser wavelength measurement device described in claim 1, characterized in that, Includes the following steps: Step 1: Build a high-precision broadband laser wavelength measurement device; Step 2: The reference laser output from the reference laser (1) is combined with the first beam split of the optical comb output from the optical comb generator (3) to generate the first beat frequency signal. The laser under test output from the laser under test (2) is combined with the second beam splitter output from the optical comb generator (3) to generate a second beat frequency signal. Second beat frequency signal First beat frequency signal And the frequency output by the optical comb generator (3) is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the frequency ratio measurement system (5); At the same time, the first beat frequency signal The frequency output by the optical comb generator (3) is equal to the carrier bias phase frequency of the optical comb. The radio frequency signal is sent to the photogenerated radio frequency signal system (4); Step 3: The photoelectric radio frequency signal system (4) generates a radio frequency reference signal. And send it to the frequency ratio measurement system (5); Step 4, Frequency ratio measurement system (5) uses radio frequency reference signal For reference, and based on the second beat frequency signal and the first beat frequency signal Calculate the frequency of the test laser relative to the reference laser. The wavelength of the laser to be tested relative to the reference laser , It represents the speed of light.

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