Atmospheric laser communication system based on all-optical wavelength converter

Abstract

The invention is suitable for the technical field of optical communication, and provides an atmospheric laser communication system based on an all-optical wavelength converter, which comprises an all-optical wavelength converter, a transmission end and a receiving end, the transmission end comprises an atmospheric environment simulation box, and the atmospheric environment simulation box comprises a cooling panel, a heating panel and a panel controller. The high-nonlinearity optical fiber all-optical wavelength converter which is simple in structure and good in flexibility is adopted as a transmitting end, the ultrahigh response speed of signal conversion is achieved, a single signal beam is effectively expanded into three beams, and stable quality during atmospheric transmission is ensured; meanwhile, the four-wave mixing effect is utilized to redistribute the wavelength, the high-capacity and multi-node requirements are met, the atmospheric environment simulation box is arranged to research the turbulence influence, and the communication performance and adaptability of the system are integrally improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical communication, and in particular relates to an atmospheric laser communication system based on an all-optical wavelength converter. Background Art

[0002] Free-space optical communication technology is a wireless communication technology that uses lasers as carriers to transmit data in free space. With the development of applications such as large-capacity cloud storage, high-definition movies, and high-definition video conferencing, users' demand for communication bandwidth and capacity is increasing. Traditional radio frequency communication technology is increasingly difficult to meet people's needs due to its bandwidth limitations. Although space communication technology has developed rapidly, it still faces many obstacles. For example, atmospheric turbulence makes it difficult to optimize the performance of free-space optical communication systems; communication technology cannot meet people's current needs for communication capacity, transmission speed, and transmission distance. Therefore, communication systems need to seek innovations to achieve greater transmission capacity and higher transmission speeds. In order to solve these problems, the present invention proposes an atmospheric laser communication system based on an all-optical wavelength converter. Summary of the invention

[0003] The purpose of the present invention is to provide an atmospheric laser communication system based on an all-optical wavelength converter, aiming to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: An atmospheric laser communication system based on an all-optical wavelength converter comprises an all-optical wavelength converter, a transmission end and a receiving end, wherein an output port of the all-optical wavelength converter is connected to an input port of the transmission end through an optical fiber, and an output port of the transmission end is connected to an input port of the receiving end through an optical fiber; The all-optical wavelength converter comprises a distributed feedback laser, a tunable laser, a polarization controller 1, a polarization controller 2, a signal modulation structure, an erbium-doped fiber amplifier 1, an erbium-doped fiber amplifier 2, a coupler and a highly nonlinear optical fiber; the light emitted by the distributed feedback laser carries information and serves as a signal light source after being modulated by the polarization controller 1 and the signal modulation structure, and is sequentially connected to the erbium-doped fiber amplifier 1 and one port (end a) of the coupler; the light emitted by the tunable laser serves as a pump light source, and is connected to the polarization controller 2 and the erbium-doped fiber amplifier 2 and then to another port (end b) of the coupler; the polarization controller 1 is used to control the polarization state of the signal light source; the polarization controller 2 is used to control the polarization state of the pump light source; the common end (end c) of the coupler is connected to the highly nonlinear optical fiber; The transmission end includes a spatial light collimator 1, an atmospheric environment simulation box and a spatial light collimator 2; the atmospheric environment simulation box includes a cooling panel, a heating panel and a panel controller; the spatial light collimator 1 is used to receive a light beam of a highly nonlinear optical fiber, and shape it into a parallel light beam and then emit it to the atmospheric environment simulation box, and the spatial light collimator 2 is used to receive a light beam from the atmospheric environment simulation box; the cooling panel is fixed on the inner upper surface of the atmospheric environment simulation box; the heating panel is fixed on the inner lower surface of the atmospheric environment simulation box; the panel controller is used to drive the cooling panel to cool and drive the heating panel to heat; The receiving end comprises a bandwidth tunable filter and a small signal amplifier; the bandwidth tunable filter is used to receive the light beam from the second spatial light collimator and then connect to the small signal amplifier.

[0005] Furthermore, the tunable laser generates pump light with a wavelength of 1545-1565 nm and an output power of 14.1 dBm; the distributed feedback laser emits signal light with a central wavelength of 1553.24 nm and an output power of 7 dBm.

[0006] Furthermore, the signal modulation structure includes an electro-optic intensity modulator, an arbitrary waveform generator and a microwave amplifier, and the output of the distributed feedback laser is connected to a polarization controller and an electro-optic intensity modulator in sequence; the arbitrary waveform generator is used to send the signal to the microwave amplifier, and the microwave amplifier is used to amplify the signal and load the signal to the electro-optic intensity modulator, and the microwave amplifier realizes signal modulation by applying a bias voltage to the electro-optic intensity modulator.

[0007] Furthermore, the maximum output power of the erbium-doped fiber amplifier 1 and the erbium-doped fiber amplifier 2 are both 1W.

[0008] Furthermore, the temperature difference between the cooling panel and the heating panel in the atmospheric environment simulation box is 50°C.

[0009] Furthermore, the bandwidth tunable filter is an OTF-950 bandwidth tunable filter.

[0010] Furthermore, the maximum output power of the small signal amplifier is 100 mW.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The atmospheric laser communication system based on all-optical wavelength converter uses an all-optical wavelength converter based on highly nonlinear optical fiber at the transmitting end. This converter has the remarkable characteristics of simple architecture and good flexibility, which provides a strong guarantee for the stable operation of the system.

[0012] 2. The atmospheric laser communication system based on the all-optical wavelength converter has an ultra-high response speed in the signal conversion process of the all-optical wavelength converter. This feature enables the system to effectively expand a single signal-carrying beam to three signal-carrying beams, thereby maintaining the quality of the communication system during atmospheric transmission.

[0013] 3. The atmospheric laser communication system based on the all-optical wavelength converter makes full use of the advantages of the all-optical wavelength converter based on the four-wave mixing effect. This converter can reallocate wavelengths and transmit the encoded information carried on a specific wavelength to other wavelengths, thereby using a limited number of wavelengths to meet the needs of high-capacity, multi-node users. In addition, in order to further study the impact of atmospheric channel turbulence on the communication system, the system also establishes an atmospheric environment simulation box, which can simulate a turbulent environment of a certain intensity through temperature difference. Therefore, the present invention establishes an atmospheric laser communication system by utilizing an all-optical wavelength converter and an atmospheric environment simulation box. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a structural schematic diagram of the signal modulation structure in the present invention.

[0016] Figure 3 It is a structural schematic diagram of the atmospheric environment simulation box in the present invention.

[0017] Figure 4 This is the relationship between the bit error rate and received power of the signal light and conversion light tests.

[0018] Figure 5 This is the eye diagram of the signal light and the conversion light.

[0019] In the figure: all-optical wavelength converter 1, distributed feedback laser 11, tunable laser 12, polarization controller 1 13, polarization controller 2 14, signal modulation structure 15, electro-optic intensity modulator 151, arbitrary waveform generator 152, microwave amplifier 153, erbium-doped fiber amplifier 1 16, erbium-doped fiber amplifier 2 17, coupler 18, high nonlinear optical fiber 19, transmission end 2, spatial light collimator 1 21, atmospheric environment simulation box 22, cooling panel 221, heating panel 222, panel controller 223, spatial light collimator 2 23, receiving end 3, bandwidth tunable filter 31, small signal amplifier 32. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] like Figure 1 As shown, an atmospheric laser communication system based on an all-optical wavelength converter is provided as an embodiment of the present invention. The system includes an all-optical wavelength converter 1, a transmission end 2 and a receiving end 3. The output port of the all-optical wavelength converter 1 is connected to the input port of the transmission end 2 through an optical fiber, and the output port of the transmission end 2 is connected to the input port of the receiving end 3 through an optical fiber.

[0022] like Figure 1 As shown, as a preferred embodiment of the present invention, the all-optical wavelength converter 1 includes a distributed feedback laser 11, a tunable laser 12, a polarization controller 13, a polarization controller 14, a signal modulation structure 15, an erbium-doped fiber amplifier 16, an erbium-doped fiber amplifier 17, a coupler 18 and a highly nonlinear optical fiber 19; the distributed feedback laser 11 is connected to the polarization controller 13 and the signal modulation structure 15, and then carries information as a signal light source, and is connected to the erbium-doped fiber amplifier 16 and the a end of the coupler 18 in sequence; the tunable laser 12 is connected to the polarization controller 14 and the erbium-doped fiber amplifier 17 as a pump light source, and then is connected to the b end of the coupler 18; the common end c of the coupler 18 is connected to the highly nonlinear optical fiber 19 to generate three light beams carrying signals.

[0023] In the embodiment of the present invention, a 10 Gb / s non-return-to-zero coded signal is loaded on the signal light source, and through the all-optical wavelength converter 1, a 30 Gb / s stable atmospheric transmission can be achieved.

[0024] In the structure of the all-optical wavelength converter 1, polarization controller 1 13 and polarization controller 2 14 are used to control the polarization state of the signal light source and the pump light source. By increasing the output power of the erbium-doped fiber amplifier, the wavelength conversion efficiency can be improved, thereby improving the signal quality. The power of the erbium-doped fiber amplifier 1 16 and the erbium-doped fiber amplifier 2 17 is amplified to 1W to obtain better signal quality. The tunable laser 12 generates pump light, which can be tuned in the range of 1545~1565nm, and the output power is 14.1dBm; the signal light is emitted by the distributed feedback laser 11, whose central wavelength is 1553.24nm and the output power is about 7dBm.

[0025] like Figure 2As shown, as a preferred embodiment of the present invention, the signal modulation structure 15 includes an electro-optic intensity modulator 151, an arbitrary waveform generator 152 and a microwave amplifier 153, and the output of the distributed feedback laser 11 is connected to the polarization controller 13 and the electro-optic intensity modulator 151 in sequence; the arbitrary waveform generator 152 sends the signal to the microwave amplifier 153, and the microwave amplifier 153 amplifies the signal and loads the signal to the electro-optic intensity modulator 151, and at the same time, the microwave amplifier 153 applies a bias voltage to the electro-optic intensity modulator 151 to complete the signal modulation.

[0026] like Figure 1 As shown, as a preferred embodiment of the present invention, the transmission end 2 includes a spatial light collimator 21, an atmospheric environment simulation box 22 and a spatial light collimator 23; the spatial light collimator 21 is used to receive three light beams carrying signals from the highly nonlinear optical fiber 19 and then shape them into parallel light beams to emit to the atmospheric environment simulation box 22, and the spatial light collimator 2 23 receives the light beams from the atmospheric environment simulation box 22.

[0027] like Figure 1 and Figure 3 As shown, as a preferred embodiment of the present invention, the atmospheric environment simulation box 22 includes a cooling panel 221, a heating panel 222 and a panel controller 223; the cooling panel 221 is fixed to the inner upper surface of the atmospheric environment simulation box 22, and the heating panel 222 is fixed to the inner lower surface of the atmospheric environment simulation box 22. The panel controller 223 drives the water pipes in the cooling panel 221 to circulate cooling through cables, and drives the electric heating wires in the heating panel 222 to heat through cables, so that a temperature difference is generated between the upper and lower parts, so that the gas inside it moves quickly, thereby generating turbulence.

[0028] like Figure 1 As shown, as a preferred embodiment of the present invention, the receiving end 3 includes a bandwidth tunable filter 31 and a small signal amplifier 32; the bandwidth tunable filter 31 receives the light beam from the spatial light collimator 23 and is connected to the small signal amplifier 32, and inputs it to the spectrometer and oscilloscope. The bandwidth tunable filter 31 uses an OTF-950 bandwidth tunable filter, which can extract signal light or conversion light, thereby completing the optical transmission task in the communication system.

[0029] Embodiment 1, system performance test; like Figure 4As shown, the bit error rate and receiving power relationship of the initial signal light and the signal light after four-wave mixing, the converted light I and the converted light II after the 50°C temperature difference atmospheric environment simulation box 22 are shown. The receiving sensitivity of the initial signal light is -34.81dBm, and the receiving sensitivities of the signal light after four-wave mixing, the converted light I and the converted light II are -33.58 dBm, -31.4dBm and -31.8 dBm respectively. It can be seen that the maximum difference in sensitivity between the signal light after four-wave mixing, the converted light I and the converted light II and the initial signal light is only 3.41dBm, and the signal is kept good, which proves that the system has good information transmission capability.

[0030] like Figure 5 As shown, Figure 5 (a) is the eye diagram of the initial signal light passing through the 50°C temperature difference atmospheric environment simulation box 22. Figure 5 (b), (c), and (d) are the eye diagrams of the signal light, the converted light I, and the converted light II after four-wave mixing through the 50°C temperature difference atmospheric environment simulation box 22. Among them, the eye diagrams of the signal light, the converted light I, and the converted light II are of good quality and highly similar to the eye diagram of the initial signal light, indicating that the system can improve the transmission capacity of communication under the premise of good signal quality.

[0031] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An atmospheric laser communication system based on an all-optical wavelength converter, characterized in that: It comprises an all-optical wavelength converter, a transmission end and a receiving end, wherein the output port of the all-optical wavelength converter is connected to the input port of the transmission end through an optical fiber, and the output port of the transmission end is connected to the input port of the receiving end through an optical fiber; The all-optical wavelength converter comprises a distributed feedback laser, a tunable laser, a polarization controller 1, a polarization controller 2, a signal modulation structure, an erbium-doped fiber amplifier 1, an erbium-doped fiber amplifier 2, a coupler and a highly nonlinear optical fiber; the light emitted by the distributed feedback laser carries information and serves as a signal light source after being modulated by the polarization controller 1 and the signal modulation structure, and is sequentially connected to the erbium-doped fiber amplifier 1 and one port of the coupler; the light emitted by the tunable laser serves as a pump light source, and is connected to the polarization controller 2 and the erbium-doped fiber amplifier 2 and then to another port of the coupler; the polarization controller 1 is used to control the polarization state of the signal light source; the polarization controller 2 is used to control the polarization state of the pump light source; the common end of the coupler is connected to the highly nonlinear optical fiber; The transmission end includes a spatial light collimator 1, an atmospheric environment simulation box and a spatial light collimator 2; the atmospheric environment simulation box includes a cooling panel, a heating panel and a panel controller; the spatial light collimator 1 is used to receive a light beam of a highly nonlinear optical fiber, and shape it into a parallel light beam and then emit it to the atmospheric environment simulation box, and the spatial light collimator 2 is used to receive a light beam from the atmospheric environment simulation box; the cooling panel is fixed on the inner upper surface of the atmospheric environment simulation box; the heating panel is fixed on the inner lower surface of the atmospheric environment simulation box; the panel controller is used to drive the cooling panel to cool and drive the heating panel to heat; The receiving end comprises a bandwidth tunable filter and a small signal amplifier; the bandwidth tunable filter is used to receive the light beam from the second spatial light collimator and then connect to the small signal amplifier.

2. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1 is characterized in that: The tunable laser generates pump light with a wavelength of 1545-1565 nm and an output power of 14.1 dBm; the distributed feedback laser emits signal light with a central wavelength of 1553.24 nm and an output power of 7 dBm.

3. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1 is characterized in that: The signal modulation structure includes an electro-optic intensity modulator, an arbitrary waveform generator and a microwave amplifier, and the output of the distributed feedback laser is connected to a polarization controller 1 and the electro-optic intensity modulator in sequence; The arbitrary waveform generator is used to send a signal to a microwave amplifier, and the microwave amplifier is used to amplify the signal and load the signal onto an electro-optic intensity modulator. Meanwhile, the microwave amplifier realizes signal modulation by applying a bias voltage to the electro-optic intensity modulator.

4. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1 is characterized in that: The maximum output power of the erbium-doped fiber amplifier 1 and the erbium-doped fiber amplifier 2 are both 1W.

5. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1 is characterized in that: The temperature difference between the cooling panel and the heating panel in the atmospheric environment simulation box is 50°C.

6. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1, characterized in that: The bandwidth tunable filter is an OTF-950 bandwidth tunable filter.

7. The atmospheric laser communication system based on the all-optical wavelength converter according to claim 1 is characterized in that: The maximum output power of the small signal amplifier is 100mW.

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