Information coding and decoding method based on Peregrine soliton ultrafast fiber laser

Abstract

The invention discloses an information coding and decoding method based on a Peregrine soliton ultrafast fiber laser, and relates to the technical field of laser photoelectronics, a laser diode pumping source, a wavelength division multiplexer, a gain fiber, a single-mode fiber, a 2 * 2 fiber coupler and a seed source form the Peregrine soliton ultrafast fiber laser. PS pulses with different spectral intervals are generated by regulating and controlling a seed source and used for quaternary coding, the time stretching module obtains the dynamic evolution process of the PS pulses in a frequency domain, the photoelectric conversion module converts optical signals collected by the optical signal collection module into electric signals, the electric information processing module processes the electric signals to obtain a quaternary coding array, and the quaternary coding array is used for coding. And converting the quaternary coding array into character information to be transmitted. According to the regulation and control method, external interference can be resisted, stable output of PS pulses and switching between states can be guaranteed, the problems of low system stability, low precision and high noise of coding and decoding are solved, and development of the fields of high-capacity all-optical storage, high-dimensional time quantum information operation and the like in the future is promoted.

Description

[0001] Field of the method

[0002] The present invention relates to the field of laser optoelectronic technology, and in particular to an information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser.

[0003] Background method

[0004] The Peregrine soliton (PS) solution, as a soliton solution of the nonlinear Schrödinger equation under a plane wave background, was first proposed by Peregrine. It is localized in both time and space and has a high peak intensity, which is of great significance in the fields of nonlinear optics, hydrodynamics, and plasma.

[0005] With the emergence of the Time-stretched Dispersive Fourier Transform (TS-DFT) technology, various complex and changeable dynamic processes in the mode-locked fiber laser system have been revealed, and it has also made it possible to observe the soliton pulses and the interactions between solitons in real time. The soliton pulses with rich time and space characteristics generated in the mode-locked fiber laser can support a variety of high-order coding formats, showing great application potential in the fields of communication, storage, and optical switching. Therefore, the encodable generation and precise control of soliton pulses have attracted extensive attention. However, in nonlinear systems, especially in ultrafast fiber lasers, although by changing the parameters of the fiber cavity, that is, polarization or pump power, optical signals at several different distances can be generated, it is difficult to precisely adjust the soliton pulses and it is also difficult to achieve soliton pulses that can be "arbitrarily" switched. Therefore, new soliton pulse generation technologies need to be proposed.

[0006] In addition, at present, the generation of optical solitons in ultrafast fiber lasers mainly depends on the modulation effect based on materials or artificial saturable absorbers, which usually have disadvantages such as low damage threshold and low environmental stability, restricting the long-term high-precision application of mode-locked fiber lasers in the fields of laser communication encoding and decoding.

[0007] Therefore, an information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser is provided to solve the above problems. Summary of the invention

[0008] The object of the present invention is to provide an information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser, define a frequency-domain customized quaternary coding format, and precisely switch the states of PS pulses with different spectral intervals by adjusting the modulation frequency of the pulses injected into the cavity, so as to promote the development of future high-capacity all-optical storage and high-dimensional time quantum information operations and other fields.

[0009] To achieve the above object, the present invention provides an information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser, comprising the following steps:

[0010] S1: By regulating the seed source of the Peregrine soliton ultrafast fiber laser, a PS pulse output carrying character information is obtained, and the PS pulse is transmitted to a time stretching module. The time stretching module uses time stretching dispersion Fourier technology to map the spectral information of the PS pulse to the time domain through a dispersion element, obtaining the dynamic evolution process of the PS pulse in the frequency domain;

[0011] S2: The time stretching module transmits the PS pulse to an optical signal acquisition module, and the optical signal acquisition module transmits the acquired optical signal to an optoelectronic conversion module; the optoelectronic conversion module converts the optical signal into an electrical signal and simultaneously transmits the electrical signal to an electrical information processing module;

[0012] S3: The electrical information processing module analyzes and processes the electrical signal to obtain a quaternary coding array, and converts the quaternary coding array into the character information to be transmitted.

[0013] Preferably, in step S1, the Peregrine soliton ultrafast fiber laser includes a wavelength division multiplexer, a laser diode pump source and a gain fiber respectively arranged on both sides of the wavelength division multiplexer. A single-mode fiber is arranged on the other side of the gain fiber, and a 2×2 fiber coupler is arranged on the other side of the single-mode fiber. A seed source is also arranged on the 2×2 fiber coupler on the side where the single-mode fiber is arranged. The other side of the 2×2 fiber coupler is connected to the wavelength division multiplexer. The wavelength division multiplexer, the gain fiber, the single-mode fiber and the 2×2 fiber coupler are sequentially connected to form a laser cavity around. The output port of the 2×2 fiber coupler is connected to the time stretching module, an optical signal acquisition module is arranged on the other side of the time stretching module, an optoelectronic conversion module is arranged on the other side of the optical signal acquisition module, and an electrical information processing module is arranged on the other side of the optoelectronic conversion module.

[0014] Preferably, in step S1, the Peregrine soliton ultrafast fiber laser outputs a PS pulse carrying character information, specifically including the following steps:

[0015] S11: According to the correspondence between the modulation frequency and the pulse interval and the spectral interval, the states of four PS pulses with different spectral intervals are defined as {0|1|2|3} of the quaternary coding;

[0016] S12: Obtain the quaternary coding of the character according to the standard eight-bit ACSII code, convert the character to be transmitted into a corresponding quaternary coding array, and generate a control signal for the seed source according to the quaternary coding array to regulate the seed source;

[0017] S13: The laser diode pump source outputs pump light. The wavelength division multiplexer couples the pump light into the gain fiber. The pump light pumps the gain fiber to obtain laser light. The 2×2 fiber coupler couples the seed source into the laser cavity. The seed source adjusts the amplitude and modulation frequency of the input signal, and adjusts the intracavity dispersion of the laser cavity through a single-mode fiber to obtain different PS pulse states.

[0018] Preferably, in step S11, the correspondence relationship between the modulation frequency and the pulse interval and the spectral interval is that when the modulation frequency increases, the pulse interval linearly decreases and the spectral interval linearly increases.

[0019] Preferably, the wavelength division multiplexer adopts a three-port wavelength division multiplexer. The three-port wavelength division multiplexer includes a common port with a central wavelength of 1550 nm, an input port with a central wavelength of 976 nm, and an input port with a central wavelength of 1550 nm. The common port with a central wavelength of 1550 nm is connected to the gain fiber. The input port with a central wavelength of 976 nm is connected to the output port of the laser diode pump source. The input port with a central wavelength of 1550 nm is connected to the output port of the 2×2 fiber coupler.

[0020] Preferably, the gain fiber is set as erbium-doped fiber, and the output wavelength of the laser diode pump source is set as 976 nm.

[0021] Preferably, the laser diode pump source, the wavelength division multiplexer, the gain fiber, the single-mode fiber, the 2×2 fiber coupler and the seed source are spliced by an optical fiber fusion splicer.

[0022] Preferably, the output of the seed source is a weak periodic modulation signal. The seed source includes a signal generator and a high-speed modulation laser diode.

[0023] Preferably, the time stretching module includes a dispersion element, a high-speed photodetector and a high-speed real-time oscilloscope. The dispersion element adopts dispersion compensation fiber, single-mode fiber or chirped fiber grating.

[0024] Preferably, in step S2, the optical signal acquisition module acquires the optical signal through a photodetector, and the photoelectric conversion module converts the optical signal into an electrical signal through an analog-to-digital converter.

[0025] Therefore, the information encoding and decoding method based on the Peregrine soliton ultrafast fiber laser with the above structure of the present invention has the following beneficial effects:

[0026] (1) Directly generate PS pulses through the extracavity injection method, and actively modulate the injected pulse ω c to achieve precise switching of PS pulses with different spectral intervals;

[0027] (2) Avoid using devices with low damage thresholds and low environmental stability such as polarization controllers and saturable absorbers, which can resist external interference and improve robustness, ensure the stable output state of PS pulses, and perform precise switching between states, solving the problems of low encoding / decoding stability, low precision, and high noise.

[0028] (3) Propose a spectrum-customized quaternary coding format, effectively improving the efficiency and flexibility of information transmission, and being able to adapt to technical fields that require high-rate information transmission.

[0029] The method solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0030] Figure 1 It is a structural diagram of a Peregrine soliton ultrafast fiber laser according to the present invention;

[0031] Figure 2 It is the quaternary coding array corresponding to "Fiber" according to the present invention;

[0032] Figure 3 It is a PS pulse carrying character information according to the present invention.

[0033] Among them: 1. Laser diode pump source; 2. Wavelength division multiplexer; 3. Gain fiber; 4. Single-mode fiber; 5. 2×2 fiber coupler; 6. Seed source; 7. Time stretching module; 8. Optical signal acquisition module; 9. Photoelectric conversion module; 10. Electrical information processing module. Detailed Embodiment

[0034] The method solution of the present invention will be further described below with reference to the drawings and embodiments.

[0035] Unless otherwise defined, the method terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0036] In the present invention, words such as "including" or "comprising" mean that the elements before this word cover the elements listed after this word, and do not exclude the possibility of also covering other elements. The orientation or positional relationship indicated by terms such as "inside", "outside", "above", "below", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In the present invention, unless otherwise clearly specified and defined, terms such as "attachment" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Embodiment

[0038] As Figure 1 shown, the present invention provides an information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser, including the following steps:

[0039] S1: By regulating the seed source of the Peregrine soliton ultrafast fiber laser, a PS pulse carrying character information is obtained, and the PS pulse is transmitted to the time stretching module 7. The time stretching module 7 uses the time stretching dispersion Fourier technique to map the spectral information of the PS pulse to the time domain through a dispersion element, and obtains the dynamic evolution process of the PS pulse in the frequency domain;

[0040] In step S1, the time stretching module 7 operates on the PS pulse using the time stretching dispersion Fourier technique. The specific principle is as follows: The PS pulse with broadband spectral information is input into dispersion elements such as a single-mode fiber, a chirped fiber grating, and a multimode waveguide to achieve the stretching of the PS pulse and the mapping of the spectral information to the time domain. Then, a high-speed photodetector and a high-speed real-time oscilloscope are used to record the time series. Finally, the time series recorded by the oscilloscope is input into a computer for data processing to obtain the dynamic evolution process of the PS pulse in the frequency domain;

[0041] In step S1, the Peregrine soliton ultrafast fiber laser outputs a PS pulse carrying character information, which specifically includes the following steps:

[0042] S11: According to the correspondence relationship between the modulation frequency and the pulse interval and the spectral interval, the states of four PS pulses with different spectral intervals are defined as {0|1|2|3} of the quaternary encoding;

[0043] In step S11, the correspondence between the modulation frequency, the pulse interval, and the spectral interval is that when the modulation frequency increases, the pulse interval decreases linearly, and the spectral interval increases linearly. Therefore, for the active modulation of the seed source, PS pulses in multiple states can be directly generated;

[0044] S12: Obtain the quaternary encoding of the character according to the standard eight-bit ASCII code, convert the character to be transmitted into a corresponding quaternary encoding array, and generate a corresponding control signal according to the quaternary encoding array to regulate the seed source 6;

[0045] S13: The laser diode pump source 1 outputs pump light, the wavelength division multiplexer 2 couples the pump light to the gain fiber 3, the pump light pumps the gain fiber 3 to generate population inversion to obtain laser light, the 2×2 fiber coupler 5 couples the seed source to the laser cavity, the seed source adjusts the signal amplitude and modulation frequency of the laser, and adjusts the intracavity dispersion of the laser cavity through the single-mode fiber 4 to optimize the output characteristics of the Peregrine soliton ultrafast fiber laser, obtaining different PS pulse states. The PS pulses are transmitted through optical fibers or optical cables to achieve information transmission;

[0046] S2: The time stretching module 7 transmits the PS pulses to the optical signal acquisition module 8, and the optical signal acquisition module 8 transmits the acquired optical signal to the optoelectronic conversion module 9; the optoelectronic conversion module 9 converts the optical signal into an electrical signal and transmits the electrical signal to the electrical information processing module 10 at the same time;

[0047] In step S2, the optical signal acquisition module 8 acquires the optical signal through a photodetector, and the optoelectronic conversion module 9 converts the optical signal into an electrical signal through an analog-to-digital converter;

[0048] S3: The electrical information processing module 10 analyzes and processes the electrical signal to obtain a quaternary encoding array, and converts the quaternary encoding array into the character information to be transmitted.

[0049] The Peregrine soliton ultrafast fiber laser includes a wavelength division multiplexer 2, a laser diode pump source 1 and a gain fiber 3 respectively arranged on both sides of the wavelength division multiplexer 2. On the other side of the gain fiber 3, there is a single-mode fiber 4. On the other side of the single-mode fiber 4, there is a 2×2 fiber coupler 5. A seed source 6 is also arranged on the 2×2 fiber coupler 5 on the side where the single-mode fiber 4 is arranged. The other side of the 2×2 fiber coupler 5 is connected to the wavelength division multiplexer 2. The wavelength division multiplexer 2, the gain fiber 3, the single-mode fiber 4, and the 2×2 fiber coupler 5 are sequentially connected to form a laser cavity around, and the laser in the laser cavity is transported in the counterclockwise direction;

[0050] The output port of the 2×2 fiber coupler 5 is connected to the time stretching module 7. On the other side of the time stretching module 7, there is an optical signal acquisition module 8. On the other side of the optical signal acquisition module 8, there is an optoelectronic conversion module 9. On the other side of the optoelectronic conversion module 9, there is an electrical information processing module 10;

[0051] The output wavelength of the laser diode pump source 1 is set to 976 nm;

[0052] The wavelength division multiplexer 2 is a three-port wavelength division multiplexer. The three-port wavelength division multiplexer includes a common port with a central wavelength of 1550 nm, an input port with a central wavelength of 976 nm, and an input port with a central wavelength of 1550 nm. The common port with a central wavelength of 1550 nm is connected to the gain fiber. The input port with a central wavelength of 976 nm is connected to the output port of the laser diode pump source 1. The input port with a central wavelength of 1550 nm is connected to the output port of the 2×2 fiber coupler 5.

[0053] The gain fiber 3 is set as erbium-doped fiber. The lowest dispersion window of the erbium-doped fiber is set for light with a wavelength close to 1550 nm. In this wavelength range, the dispersion value of the erbium-doped fiber is the smallest, and signal transmission will be more stable and reliable;

[0054] The 2×2 fiber coupler 5 is set as a 2×2 single-mode fiber coupler. The 2×2 fiber coupler 5 uses an output coupler with a splitting ratio of 5:95, 10:90, or 20:80;

[0055] The laser diode pump source 1, the wavelength division multiplexer 2, the gain fiber 3, the single-mode fiber 4, the 2×2 fiber coupler 5, and the seed source 6 are spliced using an optical fiber fusion splicer.

[0056] The seed source 6 outputs a weak periodic modulation signal. The seed source 6 includes a signal generator and a high-speed modulated laser diode, and is a key component for realizing the stable output of PS pulses and precisely controlling the state;

[0057] The time stretching module 7 includes a dispersion element, a high-speed photodetector, and a high-speed real-time oscilloscope. The dispersion element uses dispersion compensation fiber, single-mode fiber, or chirped fiber.

[0058] Taking the English word "Fiber" of the optical fiber as an example for encoding, according to the quaternary encoding format based on the ACSII code, as Figure 3 shown, the obtained quaternary information encoding array corresponding to "Fiber" is {1012|1221|1202|1211|1302}. Based on this array, the control method of the seed source can be obtained, and then a PS pulse carrying character information is obtained with 500 revolutions per cycle in the cavity as one bit of data. The PS pulse carrying character information is specifically as Figure 3 shown;

[0059] Finally, the PS pulse carrying character information is decoded by using the time stretching module 7, the optical signal acquisition module 8, the photoelectric conversion module 9 and the electrical information processing module 10 to obtain the character information to be transmitted.

[0060] Therefore, by adopting the above information encoding and decoding method based on the Peregrine soliton ultrafast fiber laser, the present invention can resist external interference to ensure the stable output and state switching of the PS pulse, solve the problems of low system stability, low precision and high noise in encoding and decoding, and promote the development of future high-capacity all-optical storage and high-dimensional time quantum information operation and other fields.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the method of the present invention, and these modifications or equivalent replacements cannot make the modified method deviate from the spirit and scope of the method of the present invention.

Claims

1. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser, characterized in that: It includes the following steps: S1: By regulating the seed source of the Peregrine soliton ultrafast fiber laser, a PS pulse output carrying character information is obtained, and the PS pulse is transmitted to the time-stretching module. The time-stretching module uses the time-stretching dispersion Fourier technique to map the spectral information of the PS pulse onto the time domain through a dispersion element, obtaining the dynamic evolution process of the PS pulse in the frequency domain; S2: The time-stretching module transmits the PS pulse to the optical signal acquisition module, and the optical signal acquisition module transmits the collected optical signal to the photoelectric conversion module; The photoelectric conversion module converts the optical signal into an electrical signal and simultaneously transmits the electrical signal to the electrical information processing module; S3: The electrical information processing module analyzes and processes the electrical signal to obtain a quaternary coding array and converts the quaternary coding array into the character information to be transmitted.

2. The information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 1, wherein: In step S1, the Peregrine soliton ultrafast fiber laser includes a wavelength division multiplexer, a laser diode pump source and a gain fiber respectively arranged on both sides of the wavelength division multiplexer. A single-mode fiber is arranged on the other side of the gain fiber, and a 2×2 fiber coupler is arranged on the other side of the single-mode fiber. A seed source is also arranged on the 2×2 fiber coupler on the side where the single-mode fiber is arranged. The other side of the 2×2 fiber coupler is connected to the wavelength division multiplexer. The wavelength division multiplexer, the gain fiber, the single-mode fiber and the 2×2 fiber coupler are sequentially connected to form a laser cavity around. The output port of the 2×2 fiber coupler is connected to the time-stretching module. An optical signal acquisition module is arranged on the other side of the time-stretching module, a photoelectric conversion module is arranged on the other side of the optical signal acquisition module, and an electrical information processing module is arranged on the other side of the photoelectric conversion module.

3. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 1, characterized in that: In step S1, the Peregrine soliton ultrafast fiber laser outputs a PS pulse carrying character information, which specifically includes the following steps: S11: According to the correspondence between the modulation frequency and the pulse interval and the spectral interval, the states of four PS pulses with different spectral intervals are defined as {0|1|2|3} of the quaternary coding; S12: Obtain the quaternary coding of the character according to the standard eight-bit ACSII code, convert the character to be transmitted into the corresponding quaternary coding array, and generate a control signal for the seed source according to the quaternary coding array to regulate the seed source; S13: The laser diode pump source outputs pump light, the wavelength division multiplexer couples the pump light into the gain fiber, the pump light pumps the gain fiber to obtain laser light, the 2×2 fiber coupler couples the seed source into the laser cavity, the seed source adjusts the amplitude and modulation frequency of the input signal, and adjusts the intracavity dispersion of the laser cavity through the single-mode fiber to obtain different PS pulse states.

4. The information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 3, characterized in that: In step S11, the correspondence between the modulation frequency and the pulse interval and the spectral interval is that when the modulation frequency increases, the pulse interval linearly decreases and the spectral interval linearly increases.

5. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 2, characterized in that: The wavelength division multiplexer adopts a three-port wavelength division multiplexer. The three-port wavelength division multiplexer includes a common port with a central wavelength of 1550 nm, an input port with a central wavelength of 976 nm, and an input port with a central wavelength of 1550 nm. The common port with a central wavelength of 1550 nm is connected to the gain fiber, the input port with a central wavelength of 976 nm is connected to the output port of the laser diode pump source, and the input port with a central wavelength of 1550 nm is connected to the output port of a 2×2 fiber coupler.

6. The information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 2, characterized in that: The gain fiber is set as erbium-doped fiber, and the output wavelength of the laser diode pump source is set as 976 nm.

7. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 2, characterized in that: The laser diode pump source, the wavelength division multiplexer, the gain fiber, the single-mode fiber, the 2×2 fiber coupler, and the seed source are spliced by an optical fiber fusion splicer.

8. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 2, characterized in that: The output of the seed source is a weak periodic modulation signal. The seed source includes a signal generator and a high-speed modulation laser diode.

9. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 2, characterized in that: The time stretching module includes a dispersion element, a high-speed photodetector, and a high-speed real-time oscilloscope. The dispersion element adopts a dispersion compensation fiber, a single-mode fiber, or a chirped fiber grating.

10. An information encoding and decoding method based on a Peregrine soliton ultrafast fiber laser according to claim 1, characterized in that: In step S2, the optical signal acquisition module acquires the optical signal through a photodetector, and the photoelectric conversion module converts the optical signal into an electrical signal through an analog-to-digital converter.

Images