Multifunctional one-way filtering and two-way monitoring system

Abstract

The present invention relates to a multifunctional unidirectional filtering and bidirectional monitoring system, comprising: an optical path isolator for receiving input pulsed light; an optical narrow bandpass filter for filtering the pulsed light output by the optical path isolator; a first monitoring device, whose input end is connected to the first output end of the optical narrow bandpass filter and obtains intensity information of the filtered pulsed light; a second output end of the optical narrow bandpass filter for outputting the filtered pulsed light to an external high-power, high-energy pulse optical fiber system; and a second monitoring device for monitoring the intensity information of the reverse SBS light of the high-power, high-energy pulse optical fiber system. The monitoring system of the present invention has a compact structure and is easy to monitor the intensity of the input pulsed light and the reverse SBS, thereby effectively protecting the connected high-power, high-energy pulse optical fiber system.

Description

Technical Field

[0001] The present application belongs to the field of optical fiber pulse technology, and specifically relates to a multifunctional unidirectional filtering and bidirectional monitoring system. Background Art

[0002] High-energy optical pulses can be used in a variety of applications, including free-space sensing and lidar. Master oscillator power amplification (MOA) is a common method used in the industry to achieve high-energy optical pulses. In this approach, a modulated laser is used as a seed, which is then amplified using a high-energy fiber amplifier.

[0003] However, to protect the seed laser during the amplification process, an isolator is often required to direct the optical signal in one direction, preventing reverse light from returning to the seed laser. Furthermore, to achieve higher-energy optical output, an optical filter is often required before the amplifier to reduce out-of-band optical noise before amplification.

[0004] To ensure that high-power optical amplifiers (HPAs) operate properly when receiving optical input, they typically use optical splitters and photodetectors to monitor the input light. However, when high-power pulses are amplified by a high-power amplifier, reverse stimulated Brillouin scattering (SBS) can occur, which can damage the seed laser and even the entire system. Therefore, a system is needed that can monitor the reverse SBS light using both the optical splitter and photodetector. Summary of the Invention

[0005] (1) Technical issues to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a multifunctional unidirectional filtering and bidirectional monitoring system, which has a compact structure and can quickly and reliably monitor the intensity of input pulse light and reverse SBS.

[0007] (2) Technical solution

[0008] To achieve the above objectives, this application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a multifunctional unidirectional filtering bidirectional monitoring system, the monitoring system comprising:

[0010] An optical isolator for receiving input pulsed light; the input pulsed light is a single-mode or polarization-maintaining light signal with a pulse width of 10-1000ns and a repetition rate of 5-100kHz;

[0011] An optical narrow bandpass filter for reducing pulse light noise, the optical narrow bandpass filter being used to filter the pulse light output by the optical isolator;

[0012] a first monitoring device for monitoring the intensity of input pulsed light, wherein the input end of the first monitoring device is connected to the first output end of the optical narrow bandpass filter and acquires intensity information of the filtered pulsed light;

[0013] The second output end of the optical narrow bandpass filter outputs the filtered pulse light to an external high-power and high-energy pulse optical fiber system;

[0014] A second monitoring device for monitoring the intensity of reverse SBS light in an external high-power, high-energy pulse optical fiber system. The second monitoring device is connected to the external high-power, high-energy pulse optical fiber system to obtain the intensity information of the reverse SBS light of the amplifier in the high-power, high-energy pulse optical fiber system.

[0015] Optionally, the optical path isolator is a unidirectional optical path isolator, and the isolation degree is greater than or equal to 25dB.

[0016] Optionally, the optical path isolator is an optical circulator.

[0017] Optionally, the optical narrow bandpass filter is a fiber Bragg grating with a thickness less than 0.1 nm, and the reflectivity of the fiber Bragg grating is greater than 99%.

[0018] Optionally, the first monitoring device and the second monitoring device are both optical fiber photoelectric detectors.

[0019] Optionally, the optical circulator is a four-port optical circulator;

[0020] The first port of the optical circulator with four output ports receives input pulse light, the second port is connected to the input end of the optical narrow bandpass filter; and the third port is connected to another input end of the first monitoring device.

[0021] The fourth port is connected to another input terminal of the second monitoring device.

[0022] Optionally, the optical isolator is connected to a laser, and the pulse light output by the laser is sent to the optical isolator.

[0023] In a second aspect, the present invention further provides a pulse light processing system, comprising a high-power, high-energy pulse optical fiber system and the multifunctional unidirectional filtering and bidirectional monitoring system described in any one of the first aspects above;

[0024] The output end of the monitoring system is connected to the input end of the high-power and high-energy pulse optical fiber system.

[0025] Optionally, the first monitoring device and the second monitoring device in the multifunctional unidirectional filtering bidirectional monitoring system are both connected to the control device of the high-power and high-energy pulse optical fiber system, so that the control device determines whether to start the high-power and high-energy pulse optical fiber system to amplify the input pulse light based on the intensity information monitored by the first monitoring device and the second monitoring device respectively.

[0026] (3) Beneficial effects

[0027] The multifunctional unidirectional filtering and bidirectional monitoring system of the present invention is a portable integrated device. As a separate optical processing device, it can quickly and reliably monitor the intensity of input pulse light and reverse SBS. At the same time, its preparation process is simple and its size is small, which can effectively reduce the complexity of production.

[0028] The multifunctional unidirectional filtering and bidirectional monitoring system of the present invention can be quickly and conveniently set at the input port of any high-power and high-energy pulse optical fiber system, and can better achieve the high-power and high-energy adjustment of the pulse light. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present application is described with the aid of the following drawings:

[0030] Figure 1 A schematic diagram of a multifunctional unidirectional filtering and bidirectional monitoring system provided by one embodiment of the present application;

[0031] Figure 2 A schematic diagram of an optical isolator provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0032] To better explain the present invention and facilitate understanding, the present invention is described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described below are merely for explaining the relevant invention and are not intended to limit the invention. It should also be noted that the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict; for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0033] Because existing devices for processing high-power and high-energy pulsed light require multiple functional optical components, are bulky, and have complex production processes, the present invention provides a multifunctional unidirectional filtering and bidirectional monitoring system for pulsed light that is compact, simple to manufacture, and meets all requirements for high-energy pulsed fiber amplifiers.

[0034] The multifunctional unidirectional filtering and bidirectional monitoring system of this embodiment is deployed in a high-power, high-energy pulse fiber system (i.e., a high-power, high-energy pulse fiber amplifier). A high-power, high-energy pulse fiber system is a fiber-optic input and output system that amplifies input pulsed light into a high-power, high-energy output. The monitoring system of this embodiment can be deployed at the input port of a high-power, high-energy pulse fiber system, providing functions such as monitoring the input optical signal and the reverse SBS signal.

[0035] The multifunctional unidirectional filtering and bidirectional monitoring system of this embodiment is an all-fiber design, has a compact size, requires no adjustment, and can be easily connected to any high-power and high-energy pulse fiber system.

[0036] like Figure 1 As shown, the multifunctional unidirectional filtering and bidirectional monitoring system of this embodiment includes: an optical path isolator 11, an optical narrow bandpass filter 12, a first monitoring device 13 for monitoring input pulse light, and a second monitoring device 14 for monitoring reverse SBS light.

[0037] The optical path isolator 11 of this embodiment is a unidirectional optical path isolator. The input end of the optical path isolator 11 is connected to an external laser pulse light generator 10. The pulse light generated by this laser pulse light generator 10 is a single-mode or polarization-maintaining light signal with a pulse width of 10-1000ns and a repetition rate of 5-100kHz.

[0038] Since a reverse optical signal is generated during optical amplification, the optical path isolator of this embodiment can block the reverse optical signal from entering the laser pulse light generator 10, thereby preventing the reverse optical signal from damaging the laser pulse light generator.

[0039] The output of optical isolator 11 is connected to the input of optical narrow bandpass filter 12, which reduces noise in the input light and has two outputs. The first output of optical narrow bandpass filter 12 is connected to the input of first monitoring device 13, which monitors the presence and intensity of an optical signal to ensure that the high-power, high-energy pulse fiber system operates only when there is an optical signal of sufficient intensity.

[0040] The optical narrow bandpass filter 12 of this embodiment transmits the narrow bandpass filtered light out of a second output port. The second output port of the optical narrow bandpass filter 12 can serve as the optical output port of a multifunctional unidirectional filtering and bidirectional monitoring system, and can be connected to a subsequent high-power, high-energy pulse fiber system.

[0041] As high-power, high-energy pulse fiber systems amplify pulses, they experience the physical phenomenon of stimulated Brillouin scattering (SBS), generating reverse pulsed light. Excessively strong SBS reverse pulsed light can weaken the amplified signal and even damage the amplifier within the high-power, high-energy pulse fiber system. The reverse SBS pulsed light generated by the amplifier then enters the second monitoring device 14 through the optical output port of the multifunctional unidirectional filtering and bidirectional monitoring system. This second monitoring device monitors the intensity of the reverse SBS pulsed light generated by the amplifier of the high-power, high-energy pulse fiber system.

[0042] In this embodiment, the intensity index monitored by the second monitoring device 14 can be used as a switch to operate the high-power and high-energy pulse fiber system, ensuring that the high-power and high-energy pulse fiber system only operates under low stimulated Brillouin scattering (SBS) pulse light intensity.

[0043] In a specific implementation process, in the multifunctional unidirectional filtering and bidirectional monitoring system of this embodiment, the unidirectional optical path isolator can be implemented by an optical circulator. In this embodiment, the isolation degree of the optical circulator is no less than 25dB.

[0044] When the optical circulator is a four-way fiber optic circulator, refer to Figure 2 The first monitoring device and the second monitoring device can be connected based on the output port of the optical fiber circulator.

[0045] In another possible implementation, the aforementioned optical narrow-bandpass filter can be a fiber Bragg grating (FBG) to reduce the noise level of the input light. Specifically, the fiber Bragg grating (FBG) has an optical narrowband of less than 0.1 nm. The fiber Bragg grating of this embodiment has an optical reflectivity of at least 99%, enabling it to output a significant portion of the signal light.

[0046] In addition, the first monitoring device and the second monitoring device are both optical fiber photoelectric detectors.

[0047] In this embodiment of the multifunctional unidirectional filtering and bidirectional monitoring system, the input end of the optical path isolator receives an external optical pulse signal, and the output end is connected to an optical narrow bandpass filter to filter and reduce noise in the received optical signal. The monitoring system is connected to a high-power, high-energy pulse fiber system to amplify the optical pulse signal while simultaneously monitoring the intensity of the input pulse light and the reverse stimulated Brillouin scattering (SBS) pulse light generated by the pulse fiber system in real time. This ensures that the high-power, high-energy pulse fiber system operates only when there is a sufficiently strong optical signal input and low stimulated Brillouin scattering (SBS) pulse light intensity.

[0048] It should be noted that, in the claims, any figure marks placed between brackets should not be understood as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiments", "examples", "specific examples" or "some examples" and the like refer to the specific features, structures, materials or characteristics described in conjunction with the embodiment or example included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0049] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments after learning the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0050] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention shall also include such modifications and variations.

Claims

1. A multifunctional one-way filtering and two-way monitoring system, characterized in that: The monitoring system is an all-fiber design, miniaturized, requires no adjustment, and can be connected to any high-power, high-energy pulse fiber system. The monitoring system includes: An optical isolator for receiving input pulsed light; the input pulsed light is a single-mode or polarization-maintaining light signal with a pulse width of 10-1000ns and a repetition rate of 5-100kHz; An optical narrow bandpass filter for reducing pulse light noise, the optical narrow bandpass filter being used to filter the pulse light output by the optical isolator; the optical narrow bandpass filter being used to ensure that the high-power, high-energy pulse fiber system operates only when an optical signal of sufficient intensity is input; a first monitoring device for monitoring the intensity of input pulsed light, wherein the input end of the first monitoring device is connected to the first output end of the optical narrow bandpass filter and acquires intensity information of the filtered pulsed light; The second output end of the optical narrow bandpass filter outputs the filtered pulse light to an external high-power and high-energy pulse optical fiber system; A second monitoring device for monitoring the intensity of reverse SBS light in an external high-power, high-energy pulse optical fiber system. The second monitoring device is connected to the external high-power, high-energy pulse optical fiber system to obtain the intensity information of the reverse SBS light of the amplifier in the high-power, high-energy pulse optical fiber system.

2. The monitoring system according to claim 1, characterized in that The optical path isolator is a unidirectional optical path isolator, and the isolation degree is greater than or equal to 25dB.

3. The monitoring system according to claim 2, characterized in that The optical path isolator is an optical circulator.

4. The monitoring system according to claim 2, characterized in that The optical narrow band pass filter is a fiber Bragg grating with a wavelength less than 0.1 nm and a light reflectivity greater than 99%.

5. The monitoring system according to claim 2, characterized in that: The first monitoring device and the second monitoring device are both optical fiber photoelectric detectors.

6. The monitoring system according to claim 3, characterized in that The optical circulator is a four-port optical circulator; The first port of the four-port optical circulator receives input pulse light, the second port is connected to the input end of the optical narrow bandpass filter; and the third port is connected to the other input end of the first monitoring device. The fourth port is connected to another input terminal of the second monitoring device.

7. The monitoring system according to any one of claims 1 to 6, characterized in that: The optical isolator is connected to the laser, and the pulse light output by the laser goes to the optical isolator.

8. A pulse light processing system, characterized in that: It comprises a high-power and high-energy pulse optical fiber system and the multifunctional unidirectional filtering and bidirectional monitoring system according to any one of claims 1 to 7 above; The output end of the monitoring system is connected to the input end of the high-power and high-energy pulse optical fiber system.

9. The pulse light processing system according to claim 8, characterized in that The first monitoring device and the second monitoring device in the multifunctional unidirectional filtering bidirectional monitoring system are both connected to the control device of the high-power and high-energy pulse optical fiber system, so that the control device determines whether to start the high-power and high-energy pulse optical fiber system to amplify the input pulse light based on the intensity information monitored by the first monitoring device and the second monitoring device respectively.

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