An all-optical quantization device and method based on soliton self-frequency shift and polarization interference

Abstract

The present invention provides an all-optical quantization device and method based on soliton self-frequency shift and polarization interference, which mainly solves the technical problems that the existing spectrum compression technology based on chirp compensation cannot achieve the best spectrum compression effect in a large power range, cannot completely compensate for the linear chirp introduced by the dispersion fiber, and cannot obtain a large spectrum compression ratio. It includes a spectrum compression module for a first high nonlinear optical fiber, a first polarization controller, and a spectrum compression module for compressing the spectrum of the optical pulse after self-frequency shift; the spectrum compression module includes an optical circulator, a polarization beam splitter, a dispersion Fourier transform module for converting the optical pulse after self-frequency shift into a linear chirped optical pulse, a phase modulation module for adding a phase factor positively correlated with its own peak power to the linear chirped optical pulse, a second polarization controller for adding an adjustable phase factor to the linear chirped optical pulse, and an analyzer for polarization interference.

Description

Technical Field

[0001] The present invention relates to an all-optical quantization device and method, and in particular to an all-optical quantization device and method based on soliton self-frequency shift and polarization interference. Background Art

[0002] Analog-to-digital converters (ADCs) have important applications in military and civilian fields such as ultra-wideband wireless communications, high-frequency broadband radars, electronic reconnaissance and countermeasures, ultra-fast signal acquisition, high-speed real-time oscilloscopes, and medical imaging. Existing electronic ADCs are limited by semiconductor carrier mobility, sampling time jitter, and comparator uncertainty, and cannot meet the growing demand for digitalization.

[0003] In contrast, optical ADC based on mode-locked laser technology has the remarkable characteristics of ultra-high speed, ultra-wideband and ultra-low time jitter. At present, optical ADCs are mainly divided into four categories: electrically sampled photonic quantization type, optically assisted type (see J. Chou, O. Boyraz, D. Solli, and B. Jalali, "Femtosecond real-time single-shot digitizer," Applied Physics Letters, 2007, 91: 161105), optically sampled electrical quantization type (see DJ Esman, AOJ Wiberg, N. Alic, and S. Radic, "Highly linear broadband photonic-assisted Q-band ADC," Journal of Lightwave Technology, 2015, 33 (11): 2256-2262) and optically sampled photonic quantization type (see T. Konishi, K. Tanimura, K. Asano, Y. Oshita, and Y. Ichioka, "All-optical analog-to-digital converter by use of self-frequency shifting in fiber and apulse-shaping technique," Journal of the Optical Society of America B, 2002, 19(11): 2817-2823). The optical sampling and optical quantization ADC first uses ultrashort optical pulse sequences to perform high-precision sampling of broadband analog signals through an electro-optical modulator, then uses ultrafast optical nonlinear effects such as soliton self-frequency shift effect and supercontinuum effect for quantization, and finally uses filter array encoding. This fully utilizes the advantages of optical sampling and avoids the mutual restriction between analog bandwidth and quantization accuracy. It is an effective way to achieve fast, ultra-wideband, low-loss, and lightweight analog-to-digital conversion.Among them, the all-optical quantization technology based on the soliton self-frequency shift effect uses the soliton self-frequency shift effect to "redshift" the central wavelength of the sampled optical pulse, where the amount of redshift is proportional to the input peak power. It is assisted by spectrum compression technology to compress the redshifted spectrum. It has the characteristics of fast speed and high precision, so it has attracted widespread attention (see T.Satoh, T.Nagashima, K.Itoh, and T.Konishi, "Power-saving approach toward 7-bit optical quantization for photonic analog-to-digital conversion," in Proceedings of CLEO-PR, 2013: 1-2).

[0004] The existing spectrum compression technology based on chirp compensation narrows the spectrum by introducing a chirp amount that is equal in magnitude and opposite in sign to the initial chirp into the optical pulse for compensation. This is achieved by using a comb structure of a single-mode fiber cascaded with a highly nonlinear fiber or a dispersion-compensating fiber cascaded with a phase modulator. Furthermore, by cascading multiple levels of comb structures, the spectrum can be compressed multiple times, further improving the quantization accuracy.

[0005] However, existing spectrum compression technologies based on chirp compensation have problems such as being unable to achieve optimal spectrum compression effects within a large power range, being unable to fully compensate for the linear chirp introduced by dispersive optical fibers, and being unable to obtain a larger spectrum compression ratio. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems that the existing spectral compression technology based on chirp compensation cannot achieve the best spectral compression effect in a large power range, cannot completely compensate for the linear chirp introduced by the dispersion optical fiber, and cannot obtain a large spectral compression ratio, and to provide an all-optical quantization device and method based on soliton self-frequency shift and polarization interference.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] An all-optical quantization device based on soliton self-frequency shift and polarization interference, which is special in that it includes a first high nonlinear optical fiber for red-shifting the central wavelength of a sampled ultrashort optical pulse sequence to obtain a self-frequency shifted optical pulse, a first polarization controller for converting a self-frequency shifted optical pulse of any polarization state into a linearly polarized light, and a spectrum compression module for compressing the spectrum of the self-frequency shifted optical pulse;

[0009] The input end of the first highly nonlinear optical fiber is used to connect to an external electro-optic modulator, and the output end of the first highly nonlinear optical fiber is connected to the input end of the first polarization controller;

[0010] The spectrum compression module includes an optical circulator, a polarization beam splitter, a dispersion Fourier transform module for converting a self-frequency-shifted optical pulse into a linear chirped optical pulse, a phase modulation module for adding a phase factor positively correlated with its own peak power to the linear chirped optical pulse, a second polarization controller for adding an adjustable phase factor to the linear chirped optical pulse, and an analyzer for polarization interference;

[0011] The input end of the dispersion Fourier transform module is connected to the output end of the first polarization controller; the a port of the optical circulator is connected to the output end of the dispersion Fourier transform module, the b port of the optical circulator is connected to the input end of the polarization beam splitter, and the c port of the optical circulator is connected to the input end of the second polarization controller; the output end of the second polarization controller is connected to the input end of the analyzer;

[0012] Two ends of the phase modulation module are respectively connected to the d-port and the e-port of the polarization beam splitter.

[0013] Furthermore, the transmission function F of the spectrum compression module satisfies the following formula:

[0014]

[0015] Where: γ is the nonlinear coefficient of the phase modulation module; β1 is the angle between the polarization transmission direction of the analyzer and the fast axis of the optical fiber; k is the coupling ratio of the polarization beam splitter (k≠1); E in is the optical pulse field of the input spectrum compression module; L2 is the transmission distance of the phase modulation module; It is the phase difference introduced by the second polarization controller between two mutually perpendicular linear polarized lights.

[0016] Furthermore, the red shift amount Δω of the central wavelength of the optical pulse after the self-frequency shift satisfies the following formula:

[0017]

[0018] Where: T0 is the pulse half width of the optical pulse sequence; T R is the Raman response time coefficient; P0 represents the peak power of the optical pulse sequence; γ1 represents the nonlinear coefficient of the first high nonlinear optical fiber; L1 represents the transmission distance of the optical pulse sequence.

[0019] Furthermore, the linear chirped optical pulse frequency domain E1(f) output by the dispersion Fourier transform module satisfies the following formula:

[0020]

[0021] Among them, β2L3 is the group velocity dispersion of the dispersion Fourier transform module; β2 is the group velocity dispersion coefficient of the dispersion Fourier transform module; L3 is the transmission distance of the dispersion Fourier transform module; f is the optical pulse frequency input to the dispersion Fourier transform module; j is the imaginary number sign in the complex number.

[0022] Furthermore, the frequency domain E of the two linearly polarized lights split by the polarization beam splitter is x (f) and E y (f) respectively satisfy the following formula:

[0023]

[0024] The optical pulse light field E2 output from the optical circulator c port satisfies the following formula:

[0025]

[0026] Where: E x and E y They are the light pulse fields of two linearly polarized lights divided by the polarization beam splitter.

[0027] Furthermore, the light intensity P output by the polarizer is out Satisfies the following formula:

[0028]

[0029] Furthermore, the dispersion Fourier transform module is a dispersion-compensating optical fiber with a positive group velocity dispersion coefficient, or a single-mode optical fiber or a fiber grating with a negative group velocity dispersion coefficient.

[0030] Furthermore, the phase modulation module is a second highly nonlinear optical fiber, or two phase modulators connected end to end.

[0031] At the same time, the present invention also provides an all-optical quantization method based on soliton self-frequency shift and polarization interference, and an all-optical quantization device based on soliton self-frequency shift and polarization interference, which is special in that it includes the following steps:

[0032] 1) Sampling the analog signal of the ultrashort optical pulse sequence through an electro-optical modulator to obtain an optical pulse sequence with the same central wavelength and different peak powers;

[0033] 2) converting the optical pulse sequence obtained after sampling into self-frequency-shifted optical pulses with red-shifted central wavelength and different peak power through a first highly nonlinear optical fiber;

[0034] 3) Linearly polarizing the self-frequency-shifted optical pulse by a first polarization controller;

[0035] 4) introducing linear chirp into the polarized self-frequency-shifted optical pulse through a dispersion Fourier transform module to obtain a linear chirped optical pulse whose time domain waveform is broadened to the same shape as its own spectrum;

[0036] 5) Introducing a phase factor positively correlated with the peak power of the linear chirped optical pulse;

[0037] 6) adding an adjustable phase factor to the linear chirped light pulse through a second polarization controller to achieve optimal spectral compression of linear chirped light pulses with different peak powers;

[0038] 7) Perform polarization interference on the linear chirped light pulse through a polarizer, so that the central wavelength with high peak power in the linear chirped light pulse passes through without loss, and the long and short wavelength components with low peak power are completely filtered out;

[0039] 8) Complete spectral compression and full optical quantization.

[0040] Furthermore, step 5) is specifically implemented according to the following steps:

[0041] 5.1) The linear chirped light pulse is input from the a port and output from the b port of the optical circulator, and is split into two linear polarized light beams with mutually perpendicular polarization directions by a polarization beam splitter, and the two linear polarized light beams are transmitted to the phase modulation module in the clockwise and counterclockwise directions respectively;

[0042] 5.2) A phase factor positively correlated with the peak power is introduced into both linearly polarized beams through a phase modulation module;

[0043] 5.3) Two beams of linearly polarized light with phase factors positively correlated with the peak power are combined into one after passing through the polarization beam splitter in the opposite direction, and are input from the b port and output from the c port of the optical circulator.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention utilizes the soliton self-frequency shift effect to realize fast all-optical quantization of broadband analog signals in a large power range. By introducing a phase factor that is positively correlated with the peak power of the linear chirped optical pulse after conversion, the problem that the traditional all-optical quantization device based on chirp compensation cannot fully compensate for the introduced linear chirped optical pulse is effectively overcome. By adding an adjustable phase factor to the linear chirped optical pulse, fast and efficient spectral compression of optical pulses with different peak powers and different wavelengths is achieved, and the spectral compression ratio is improved. The present invention realizes power-dependent filtering characteristics through polarization interference, improves the accuracy of all-optical quantization, and does not require single-mode optical fiber and high nonlinear optical fiber with fixed parameter ratios. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1It is a structural schematic diagram of an embodiment of an all-optical quantization device based on soliton self-frequency shift and polarization interference of the present invention;

[0047] Figure 2 This is a schematic diagram of the principle of an embodiment of an all-optical quantization device based on soliton self-frequency shift and polarization interference of the present invention. (In the figure, t is time, i is the waveform of the optical pulse sequence obtained after sampling, ii is the waveform of the optical pulse after self-frequency shift, iii is the waveform of the linear chirped optical pulse in the spectrum compression module, and iv is the waveform of the linear chirped optical pulse after polarization interference) DETAILED DESCRIPTION

[0048] In order to make the purpose, advantages and features of the present invention clearer, the following is a further detailed description of an all-optical quantization device and method based on soliton self-frequency shift and polarization interference proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following specific implementation methods, the advantages and features of the present invention will be clearer. It should be noted that: the drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention; secondly, the structure shown in the drawings is often part of the actual structure.

[0049] In the description of the present invention, it needs to be explained that the terms "counterclockwise", "clockwise" and the like are only used to clearly describe the present invention.

[0050] like Figure 1 As shown, the present invention is an all-optical quantization device based on soliton self-frequency shift and polarization interference, comprising a first high nonlinear optical fiber for red-shifting the central wavelength of a sampled ultrashort optical pulse sequence to obtain a self-frequency shifted optical pulse, a first polarization controller for converting a self-frequency shifted optical pulse of any polarization state into a linearly polarized light, and a spectrum compression module for compressing the spectrum of the self-frequency shifted optical pulse. The working principle is as follows Figure 2 As shown;

[0051] The red shift of the central wavelength of the optical pulse after self-frequency shift obtained by the first highly nonlinear optical fiber satisfies the following formula:

[0052]

[0053] Where: T0 is the pulse half width of the optical pulse sequence; T R is the Raman response time coefficient; P0 represents the peak power of the optical pulse sequence; γ1 represents the nonlinear coefficient of the first high nonlinear optical fiber; L1 represents the transmission distance of the optical pulse sequence.

[0054] It can be seen from the above formula that the self-frequency shift Δω is proportional to the peak power P0 of the optical pulse sequence and the transmission distance L1 of the optical pulse sequence, and is proportional to the square of the pulse half-width T0 of the optical pulse sequence. 2Therefore, all-optical quantization can be achieved with the help of this "power-wavelength" mapping relationship.

[0055] The input end of the first highly nonlinear optical fiber is used to connect to an external electro-optic modulator, and the analog signal of the ultrashort optical pulse sequence is sampled through the external electro-optic modulator. The output end of the first highly nonlinear optical fiber is connected to the input end of the first polarization controller; the spectrum compression module includes an optical circulator, a polarization beam splitter, a dispersion Fourier transform module for converting the self-frequency-shifted optical pulse into a linear chirped optical pulse, a phase modulation module for adding a phase factor positively correlated with the peak power to the linear chirped optical pulse, a second polarization controller for adding an adjustable phase factor to the linear chirped optical pulse, and an analyzer for polarization interference;

[0056] The input end of the dispersion Fourier transform module is connected to the output end of the first polarization controller;

[0057] The frequency domain E1(f) of the linear chirped optical pulse output by the dispersion Fourier transform module satisfies the following formula:

[0058]

[0059] Among them, β2L3 is the group velocity dispersion of the dispersion Fourier transform module; β2 is the group velocity dispersion coefficient of the dispersion Fourier transform module; L3 is the transmission distance of the dispersion Fourier transform module; f is the optical pulse frequency input to the dispersion Fourier transform module; j is the imaginary number sign in the complex number.

[0060] The a port of the optical circulator is connected to the output end of the dispersion Fourier transform module, the b port of the optical circulator is connected to the input end of the polarization beam splitter, and the c port of the optical circulator is connected to the input end of the second polarization controller; the output end of the second polarization controller is connected to the input end of the analyzer; and the two ends of the phase modulation module are respectively connected to the d port and the e port of the polarization beam splitter.

[0061] The frequency domain E of the two linearly polarized lights split by the polarization beam splitter x (f) and E y (f) respectively satisfy the following formula:

[0062]

[0063] The optical pulse field E2 output from the optical circulator c port satisfies the following formula:

[0064]

[0065] Where: E x and E y They are the light pulse light fields of two linearly polarized lights divided by the polarization beam splitter;

[0066] The light intensity P output by the polarizer out Satisfies the following formula:

[0067]

[0068] It can be seen that with the input light intensity (i.e., the polarization state of the first polarization controller, the light pulse intensity after self-frequency shift), the polarization beam splitter coupling ratio k, the phase modulation module parameters (nonlinear coefficient γ, length L2), the angle β1 between the polarization analyzer transmission direction and the fiber block axis, and the polarization state of the second polarization controller By properly setting β1 and k, the long and short wavelength components can be almost completely filtered out, and flexible control Different peak powers and different central wavelength components are output almost losslessly, thereby realizing efficient, ultrafast, base-free all-optical quantization within a large peak power range. At the same time, the present invention has no strict requirements on the dispersion amount of the dispersion Fourier transform module and the transmission length of the phase modulation module in the spectrum compression structure.

[0069] Therefore, the transfer function F of the spectrum compression module satisfies the following formula:

[0070]

[0071] Where: γ is the nonlinear coefficient of the phase modulation module; β1 is the angle between the polarization transmission direction of the analyzer and the fast axis of the optical fiber; k is the coupling ratio of the polarization beam splitter (k≠1); E in is the optical pulse field of the input spectrum compression module; L2 is the transmission distance of the phase modulation module; It is the phase difference introduced by the second polarization controller between two mutually perpendicular linear polarized lights.

[0072] According to the above formula, the response function of the spectrum compression module is related to the input pulse peak power, the polarization state of the second polarization controller, the coupling ratio of the polarization beam splitter, the parameters of the phase modulation module, and the vibration transmission direction of the analyzer, and changes in a cosine function. By reasonably setting β1, k, γ, and L2, the input low-power long and short wavelength components can be completely filtered out, and the high-power center wavelength components can pass almost losslessly. Compared with the traditional all-optical quantization method based on chirp compensation, the present invention can flexibly adjust It can allow central wavelengths of different powers to pass through almost losslessly, achieving high-speed, efficient and high-precision all-optical quantization of optical pulses in a large peak power range. There is no need for a base and there are no fixed requirements for the dispersion amount of the dispersion Fourier transform module and the transmission length of the phase modulation module.

[0073] Among them, in a preferred embodiment of the present invention, the dispersion Fourier transform module is a dispersion-compensating optical fiber with a positive group velocity dispersion coefficient, or a single-mode optical fiber or optical fiber grating with a negative group velocity dispersion coefficient; in other embodiments of the present invention, those skilled in the art may also replace it with other similar devices in the prior art; in a preferred embodiment of the present invention, the phase modulation module is a second high nonlinear optical fiber, or two phase modulators connected end to end; in other embodiments of the present invention, those skilled in the art may also replace it with other similar devices in the prior art.

[0074] The present invention also provides an all-optical quantization method based on soliton self-frequency shift and polarization interference, using an all-optical quantization device based on soliton self-frequency shift and polarization interference, comprising the following steps:

[0075] 1) Sampling the analog signal of the ultrashort optical pulse sequence through an electro-optical modulator to obtain an optical pulse sequence with the same central wavelength and different peak powers;

[0076] 2) Using the soliton self-frequency shift effect through the first highly nonlinear optical fiber, the optical pulse sequence obtained after sampling is converted into a self-frequency shifted optical pulse with a red-shifted central wavelength and different peak power; that is, the power information of the optical pulse sequence after sampling is mapped to the wavelength domain ("intensity-wavelength" mapping);

[0077] 3) Linearly polarizing the self-frequency-shifted optical pulse by a first polarization controller;

[0078] 4) Through the group velocity dispersion effect of the dispersion Fourier transform module, linear chirp is introduced into the polarized self-frequency shifted optical pulse to obtain a linear chirped optical pulse whose time domain waveform is broadened to the same shape as its own spectrum; (the higher power central wavelength component is located at the center of the pulse, and the lower power long and short wavelength components are located at the edge of the pulse, "wavelength-time-intensity" mapping)

[0079] 5) Introducing a phase factor positively correlated with the peak power of the linear chirped optical pulse;

[0080] 5.1) The linear chirped light pulse is input from the a port and output from the b port of the optical circulator, and is split into two linear polarized light beams with mutually perpendicular polarization directions by a polarization beam splitter, and the two linear polarized light beams are transmitted to the phase modulation module in the clockwise and counterclockwise directions respectively;

[0081] 5.2) Using the optical nonlinear effect through the phase modulation module, a phase factor positively correlated with the peak power is introduced into both linearly polarized beams;

[0082] 5.3) The two linearly polarized lights are combined into one beam after passing through the polarization beam splitter in opposite directions, and then input from port b and output from port c of the optical circulator;

[0083] 6) adding an adjustable phase factor to the linear chirped optical pulse output from the c-port of the optical circulator through a second polarization controller to achieve optimal spectral compression of linear chirped optical pulses with different peak powers;

[0084] 7) Perform polarization interference on the linear chirped light pulse through the polarizer, so that the central wavelength with high peak power in the linear chirped light pulse passes through without loss, and the long and short wavelength components with low peak power are completely filtered out; ("intensity-phase-intensity" mapping)

[0085] 8) Complete spectral compression and full optical quantization.

Claims

1. An all-optical quantization device based on soliton self-frequency shift and polarization interference, characterized in that: It includes a first highly nonlinear optical fiber for red-shifting the central wavelength of a sampled ultrashort optical pulse sequence to obtain a self-frequency-shifted optical pulse, a first polarization controller for converting a self-frequency-shifted optical pulse of any polarization state into a linearly polarized light, and a spectrum compression module for compressing the spectrum of the self-frequency-shifted optical pulse; The input end of the first highly nonlinear optical fiber is used to connect to an external electro-optic modulator, and the output end of the first highly nonlinear optical fiber is connected to the input end of the first polarization controller; The spectrum compression module includes an optical circulator, a polarization beam splitter, a dispersion Fourier transform module for converting a self-frequency-shifted optical pulse into a linear chirped optical pulse, a phase modulation module for adding a phase factor positively correlated with its own peak power to the linear chirped optical pulse, a second polarization controller for adding an adjustable phase factor to the linear chirped optical pulse, and an analyzer for polarization interference; The input end of the dispersion Fourier transform module is connected to the output end of the first polarization controller; the a port of the optical circulator is connected to the output end of the dispersion Fourier transform module, the b port of the optical circulator is connected to the input end of the polarization beam splitter, and the c port of the optical circulator is connected to the input end of the second polarization controller; the output end of the second polarization controller is connected to the input end of the analyzer; Two ends of the phase modulation module are respectively connected to the d-port and the e-port of the polarization beam splitter.

2. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 1, characterized in that: The transmission function F of the spectrum compression module satisfies the following formula: Where: γ is the nonlinear coefficient of the phase modulation module; β1 is the angle between the polarization transmission direction of the analyzer and the fast axis of the optical fiber; k is the coupling ratio of the polarization beam splitter, k≠1; E in is the optical pulse field of the input spectrum compression module; L2 is the transmission distance of the phase modulation module; It is the phase difference introduced by the second polarization controller between two mutually perpendicular linear polarized lights.

3. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 2, characterized in that: The red shift amount Δω of the central wavelength of the light pulse after the self-frequency shift satisfies the following formula: Where: T0 is the pulse half width of the optical pulse sequence; T R is the Raman response time coefficient; P0 represents the peak power of the optical pulse sequence; γ1 represents the nonlinear coefficient of the first high nonlinear optical fiber; L1 represents the transmission distance of the optical pulse sequence.

4. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 3, characterized in that: The linear chirped optical pulse frequency domain E1(f) output by the dispersion Fourier transform module satisfies the following formula: Among them, β2L3 is the group velocity dispersion of the dispersion Fourier transform module; β2 is the group velocity dispersion coefficient of the dispersion Fourier transform module; L3 is the transmission distance of the dispersion Fourier transform module; f is the optical pulse frequency input to the dispersion Fourier transform module; j is the imaginary number sign in the complex number.

5. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 4, characterized in that: The frequency domain E of the two linearly polarized lights split by the polarization beam splitter x (f) and E y (f) respectively satisfy the following formula: The optical pulse light field E2 output from the optical circulator c port satisfies the following formula: Where: E x and E y They are the light pulse fields of two linearly polarized lights divided by the polarization beam splitter.

6. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 5, characterized in that: The light intensity P output by the analyzer out Satisfies the following formula:

7. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 6, characterized in that: The dispersion Fourier transform module is a dispersion compensating optical fiber with a positive group velocity dispersion coefficient, or a single-mode optical fiber or optical fiber grating with a negative group velocity dispersion coefficient.

8. The all-optical quantization device based on soliton self-frequency shift and polarization interference according to claim 7, characterized in that: The phase modulation module is a second highly nonlinear optical fiber, or two phase modulators connected end to end.

9. An all-optical quantization method based on soliton self-frequency shift and polarization interference, using an all-optical quantization device based on soliton self-frequency shift and polarization interference as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Sampling the analog signal of the ultrashort optical pulse sequence through an electro-optical modulator to obtain an optical pulse sequence with the same central wavelength and different peak powers; 2) converting the optical pulse sequence obtained after sampling into self-frequency-shifted optical pulses with red-shifted central wavelength and different peak power through a first highly nonlinear optical fiber; 3) Linearly polarizing the self-frequency-shifted optical pulse by a first polarization controller; 4) introducing linear chirp into the polarized self-frequency-shifted optical pulse through a dispersion Fourier transform module to obtain a linear chirped optical pulse whose time domain waveform is broadened to the same shape as its own spectrum; 5) Introducing a phase factor positively correlated with the peak power of the linear chirped optical pulse; 6) adding an adjustable phase factor to the linear chirped light pulses through a second polarization controller so as to achieve optimal spectral compression of the linear chirped light pulses with different peak powers; 7) Perform polarization interference on the linear chirped light pulse through a polarizer, so that the central wavelength with high peak power in the linear chirped light pulse passes through without loss, and the long and short wavelength components with low peak power are completely filtered out; 8) Complete spectral compression and full optical quantization.

10. The all-optical quantization method based on soliton self-frequency shift and polarization interference according to claim 9, characterized in that: Step 5) is implemented according to the following steps: 5.1) The linear chirped light pulse is input from the a port and output from the b port of the optical circulator, and is split into two linear polarized light beams with mutually perpendicular polarization directions by a polarization beam splitter, and the two linear polarized light beams are transmitted to the phase modulation module in the clockwise and counterclockwise directions respectively; 5.2) A phase factor positively correlated with the peak power is introduced into both linearly polarized beams through a phase modulation module; 5.3) Two beams of linearly polarized light with phase factors positively correlated with the peak power are combined into one after passing through the polarization beam splitter in the opposite direction, and are input from the b port and output from the c port of the optical circulator.

Images