System for inscribing single-wavelength continuous weak grating based on reflectivity real-time monitoring

Abstract

The invention relates to the technical field of fiber bragg grating inscribing, in particular to a reflectivity-based real-time monitoring inscribing single-wavelength continuous weak grating system, and a to-be-inscribed fiber is used for bearing the inscribed fiber and executing the inscribing task of the grating; the light path inscribing system is used for inscribing a single-wavelength weak grating on the optical fiber to be inscribed; the broadband light source is used for detecting reflected light of the single-wavelength weak grating; the precise 3D transmission platform is used for fixing and moving an optical fiber to be inscribed to a continuous inscribing position; the spectrograph is used for measuring spectral data reflected by the optical fiber; the data collector is used for collecting reflected optical signal data in real time and carrying out signal processing and analysis; the display terminal is used for displaying reflected spectral data and grating inscribing quality information in real time, the accuracy and efficiency in the optical fiber single-wavelength weak grating inscribing process are improved through a dynamic feedback mechanism, continuous grating inscribing is supported, and meanwhile high inscribing quality and high inscribing efficiency are met.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber grating writing, and in particular to a single-wavelength continuous weak grating system based on real-time reflectivity monitoring. Background Art

[0002] Currently, fiber Bragg grating technology is widely used in fiber optic sensing, optical communications and optical devices. For the writing of fiber Bragg grating, the commonly used methods include using an external light source to write directly through the optical fiber and using the interference principle to make the grating structure of the optical fiber. However, although the existing fiber weak grating writing system can achieve basic grating writing, it has significant deficiencies in the following aspects: 1. Real-time monitoring is difficult, and it is impossible to provide real-time feedback on the quality of single-wavelength weak gratings during the writing process, which may cause the quality of weak gratings to fail to meet the predetermined requirements.

[0003] 2. Low efficiency. After each single-wavelength weak grating writing is completed, the system cannot evaluate and adjust the quality of continuous single-wavelength weak grating writing, resulting in repeated operations and a waste of time and resources.

[0004] 3. Continuous engraving cannot be achieved. During the engraving process of multiple single-wavelength weak gratings, integrated and continuous real-time monitoring and adjustment cannot be achieved, which affects production efficiency and engraving quality.

[0005] The purpose of the present invention is to provide corresponding solutions to the above-mentioned technical problems. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a single-wavelength continuous weak grating system based on real-time monitoring of reflectivity for writing, which improves the accuracy and efficiency of the optical fiber single-wavelength weak grating writing process through a dynamic feedback mechanism, and also supports continuous grating writing, while meeting the high quality and high efficiency of writing.

[0007] The technical solution adopted by the present invention is as follows: a system for real-time monitoring and writing of a single-wavelength continuous weak grating based on reflectivity, comprising an optical fiber to be written, an optical path writing system, a broadband light source, a precision 3D transmission platform, a spectrometer, a data collector and a display terminal, wherein the spectrometer, the data collector and the display terminal are electrically connected in sequence; the optical fiber to be written is used to carry the optical fiber to be written and perform the grating writing task; the optical path writing system is used to write a single-wavelength weak grating on the optical fiber to be written; the broadband light source is used to detect the reflected light of the single-wavelength weak grating; the precision 3D transmission platform is used to fix and move the optical fiber to be written to a continuous writing position; the spectrometer is used to measure the spectral data reflected by the optical fiber; the data collector is used to collect the reflected light signal data in real time, and perform signal processing and analysis; the display terminal is used to display the reflected spectral data and grating writing quality information in real time.

[0008] It also includes an optical fiber circulator, one end of which is connected to the optical fiber to be written and the other end is connected to a broadband light source. The optical fiber circulator is used to separate and guide the optical signal to the optical fiber to be written, and guide the reflected light to the spectrometer.

[0009] The optical path writing system adjusts the working modes of the UV light source and the optical fiber circulator, irradiates the writing light source to the optical fiber to be written, and completes the writing of the single-wavelength weak grating on the optical fiber.

[0010] The data collector adjusts the UV light source power or writing time in real time to maintain the reflectivity deviation within ±0.5%.

[0011] The wavelength of the UV light source of the optical path writing system is 248 nm, the grating reflectivity is 5%, and the grating spacing is 2 cm.

[0012] The broadband light source provides a light source with an operating wavelength range of 1530nm to 1560nm.

[0013] The data collector is used for real-time analysis of the 3dB spectrum width, main peak depression and symmetry of the reflection spectrum.

[0014] The position control accuracy of the precision 3D transmission platform is ±1μm, and it supports continuous writing of more than 100 weak gratings with a single optical fiber.

[0015] The beneficial effects of the present invention are as follows: the present invention can monitor the reflectivity in real time, and improve the accuracy and efficiency in the process of optical fiber single-wavelength weak grating writing through a dynamic feedback mechanism, that is, the spectrometer, data acquisition device and display terminal connected in sequence can collect and analyze the reflection spectrum data in real time, and the system can adjust the writing parameters in real time to avoid error accumulation in the grating writing process. It also realizes continuous grating writing by moving the optical fiber to be written through a tight 3D transmission platform, while meeting the high quality and high efficiency of writing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0017] Figure 1 It is a structural schematic diagram of a system for writing a single-wavelength continuous weak grating based on real-time reflectivity monitoring according to the present invention; Figure 2 It is a schematic diagram of the optical fiber writing and reflection spectrum of the present invention; In the figure, 1-optical fiber to be engraved, 2-optical path engraving system, 3-broadband light source, 4-precision 3D transmission platform, 5-spectrometer, 6-data collector, 7-display terminal, 8-optical fiber circulator. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0020] The directions and positions mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inside", "outside", "top", "bottom", "side", etc., are only for reference to the directions or positions of the drawings. Therefore, the directions and positions used are for explaining and understanding the present invention, but not for limiting the scope of protection of the present invention.

[0021] like Figure 1 to Figure 2 As shown, an embodiment of the present invention is a system for real-time monitoring and writing of a single-wavelength continuous weak grating based on reflectivity, comprising an optical fiber to be written 1, an optical path writing system 2, a broadband light source 3, a precision 3D transmission platform 4, a spectrometer 5, a data collector 6 and a display terminal 7, wherein the spectrometer 5, the data collector 6 and the display terminal 7 are electrically connected in sequence; the optical fiber to be written 1 is used to carry the optical fiber to be written and perform the writing task of the grating; the optical path writing system 2 is used to write a single-wavelength weak grating on the optical fiber to be written 1; the broadband light source 3 is used to detect the reflected light of the single-wavelength weak grating; the precision 3D transmission platform 4 is used to fix and move the optical fiber to be written 1 to a continuous writing position; the spectrometer 5 is used to measure the spectral data reflected by the optical fiber; the data collector 6 is used to collect the reflected light signal data in real time, and perform signal processing and analysis; the display terminal 7 is used to display the reflected spectral data and grating writing quality information in real time.

[0022] The beneficial effects of such a configuration are as follows: the present invention can monitor the reflectivity in real time, and improve the accuracy and efficiency of the optical fiber single-wavelength weak grating writing process through a dynamic feedback mechanism, that is, the spectrometer, data acquisition device and display terminal connected in sequence can collect and analyze the reflection spectrum data in real time, and the system can adjust the writing parameters in real time to avoid error accumulation during the grating writing process. Continuous grating writing can also be achieved by moving the optical fiber to be written through a tight 3D transmission platform, while meeting the high quality and high efficiency of the writing.

[0023] Further configuration includes a fiber optic circulator 8, one end of which is connected to the optical fiber 1 to be written and the other end is connected to the broadband light source 3. The fiber optic circulator 8 is used to separate and guide the optical signal to the optical fiber 1 to be written, and guide the reflected light to the spectrometer 5.

[0024] It is further configured that the optical path writing system 2 irradiates the writing light source to the optical fiber 1 to be written by adjusting the working mode of the UV light source and the optical fiber circulator 8, thereby completing the writing of the single-wavelength weak grating on the optical fiber.

[0025] It is further configured that the data collector 6 adjusts the UV light source power or the writing time in real time to maintain the reflectivity deviation within ±0.5%.

[0026] It is further configured that the UV light source wavelength of the optical path writing system 2 is 248 nm, the grating reflectivity is 5%, and the grating spacing is 2 cm.

[0027] It is further provided that the broadband light source 3 provides a light source with an operating wavelength range of 1530 nm to 1560 nm.

[0028] It is further configured that the data collector 6 is used for real-time analysis of the 3 dB spectrum width, main peak depression and symmetry of the reflection spectrum.

[0029] It is further configured that the position control accuracy of the precision 3D transmission platform 4 is ±1 μm, supporting continuous writing of more than 100 weak gratings on a single optical fiber.

[0030] The system equipment and workflow include the following steps: 1. Writing optical path: By precisely adjusting the working mode of the UV light source (248nm) and the fiber circulator, the writing light source is irradiated to the optical fiber to be written, and the continuous, single-wavelength weak reflection grating is written on the optical fiber. The central wavelength of the grating is set to 1550nm, the reflectivity is 5%, and the grating spacing is 2cm.

[0031] 2. Fiber circulator connection: The broadband light source is connected to the fiber circulator, and the fiber circulator is connected to the optical fiber to be written to complete the transmission and reflection of the optical signal. The reflected light is sent to the spectrometer through the fiber circulator.

[0032] 3. Precision 3D transmission platform: The platform is used to accurately fix the optical fiber to be written, and automatically transfer the optical fiber to the next writing position after each weak grating is written, ensuring continuous writing of the weak grating.

[0033] 4. Reflected light data collection and analysis: The optical fiber to be inscribed is connected to the spectrometer through a fiber optic circulator to collect the light signal reflected by the optical fiber, which is finally analyzed by a data collector and displayed on the display terminal.

[0034] The working principle of this system is as follows: 1. Grating writing: The writing optical path of the system illuminates the optical fiber to be written to complete the writing of the first weak grating. The broadband light source (wavelength range: 1530nm-1560nm, power: 23mW) illuminates the optical fiber to be written through the optical fiber circulator to form a weak reflection grating with a reflectivity of 5%. The reflected light of the first grating is received by the spectrometer and transmitted to the display terminal in real time through the data acquisition device.

[0035] 2. Reflection spectrum analysis: The display terminal shows the reflection spectrum, where the reflected light power at the central wavelength of 1550nm is 1mW. The writing quality of the first grating is evaluated by real-time analysis of the 3dB spectrum width, main peak depression and symmetry of the reflection spectrum.

[0036] 3. Continuous single-wavelength weak grating writing and detection: After completing the reflection spectrum analysis of the first weak grating, the blank area of ​​the optical fiber to be written is transmitted to the writing optical path using a precision 3D transmission platform to start writing the second weak grating. The writing parameters of the second weak grating are consistent with those of the first weak grating. The quality of the second weak grating is tested through real-time reflection spectrum analysis.

[0037] 4. Multi-grating quality assessment: Similarly, the system writes multiple gratings in sequence and detects the quality of the reflected light spectrum of each weak grating in real time, such as Figure 2 As shown in , the change in reflected light power and quality analysis of the reflection spectrum help monitor the stability and accuracy of the writing process.

[0038] Advantages and innovations of this system: High-precision reflectivity monitoring: Through the collection and analysis of real-time reflection spectrum data, the writing quality of each grating is accurately evaluated to ensure high stability and high precision of the writing process.

[0039] Continuous weak grating writing: The system supports continuous grating writing, which can write multiple weak reflection gratings on the same optical fiber in sequence, improving the utilization rate and production efficiency of the optical fiber.

[0040] Real-time quality feedback and optimization: Through reflection spectrum analysis, the system can adjust the writing parameters in real time to avoid error accumulation during the grating writing process.

[0041] Automation and precision control: The precision 3D transmission platform can automatically transmit the optical fiber to be inscribed and accurately control the position of the optical fiber to ensure the writing position and accuracy of each grating.

[0042] Equipment integration and miniaturization: The system equipment of the present invention is compact and suitable for integration into a miniaturized optical fiber writing platform, and is suitable for precision optical fiber processing and efficient mass production.

[0043] Figure 2The schematic diagram of the reflection spectrum is shown, showing the reflected light power of each grating during the grating writing process, its 3dB spectrum width, main peak depression and other analysis results, which help evaluate the quality of the grating. The grating writing optical path illuminates the optical fiber to be written to complete the writing of the first grating. The 23mw broadband light source with a central wavelength of 1550nm passes through the circulator and passes through the weak reflection grating with a reflectivity of 5%. The first grating reflected light is received by the spectrometer and displayed on the display terminal through the data collector.

[0044] like Figure 2 As shown by the thick line in the figure, the reflected light power of the central wavelength of 1550nm is 1mw. In addition, the writing quality of the first weak grating is evaluated by real-time analysis of the 3dB spectrum width, the depression of the main peak, and the symmetry of the reflection spectrum. After completing the evaluation of the writing quality of the first weak grating reflection spectrum. Using a precision 3D transmission platform, the blank area of ​​the optical fiber to be written is transmitted to the writing optical path. The writing grating parameters are the same as those of the first weak grating. Continuous writing is performed and the writing is completed. Figure 2 As shown by the thin line in , the reflected light power at the central wavelength of 1550nm is 0.95mw, and the quality analysis of the reflection spectrum is performed. Figure 2 The dotted line in is the reflected light spectrum after the third weak grating is written. Similarly, the grating performance of the fourth, fifth, and Nth weak gratings is tested in real time.

[0045] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring, characterized in that: It comprises an optical fiber to be inscribed (1), an optical path inscription system (2), a broadband light source (3), a precision 3D transmission platform (4), a spectrometer (5), a data collector (6) and a display terminal (7), wherein the spectrometer (5), the data collector (6) and the display terminal (7) are electrically connected in sequence; The optical fiber to be inscribed (1) is used to carry the optical fiber to be inscribed and to perform the task of writing the grating; The optical path writing system (2) is used to write a single-wavelength weak grating on the optical fiber (1) to be written; The broadband light source (3) is used to detect the reflected light of the single-wavelength weak grating; The precision 3D transmission platform (4) is used to fix and move the optical fiber (1) to be inscribed to a continuous inscription position; The spectrometer (5) is used to measure the spectral data reflected by the optical fiber; The data collector (6) is used to collect reflected light signal data in real time and perform signal processing and analysis; The display terminal (7) is used for displaying reflected spectrum data and grating writing quality information in real time.

2. According to claim 1, a system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring, characterized in that: It also includes an optical fiber circulator (8), one end of which is connected to the optical fiber to be inscribed (1) and the other end of which is connected to the broadband light source (3). The optical fiber circulator (8) is used to separate and guide the optical signal to the optical fiber to be inscribed (1), and simultaneously guide the reflected light to the spectrometer (5).

3. A system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring according to claim 2, characterized in that: The optical path writing system (2) adjusts the working modes of the UV light source and the optical fiber circulator (8) to irradiate the writing light source to the optical fiber (1) to be written, thereby completing the writing of a single-wavelength weak grating on the optical fiber.

4. A system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring according to claim 3, characterized in that: The data collector (6) adjusts the UV light source power or writing time in real time to maintain the reflectivity deviation within ±0.5%.

5. According to claim 3, a system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring is characterized in that: The UV light source wavelength of the optical path writing system (2) is 248 nm, the grating reflectivity is 5%, and the grating spacing is 2 cm.

6. The system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring according to claim 1, characterized in that: The broadband light source (3) provides a light source with an operating wavelength range of 1530 nm to 1560 nm.

7. The system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring according to claim 1 is characterized by: The data collector (6) is used for real-time analysis of the 3 dB spectrum width, main peak depression and symmetry of the reflection spectrum.

8. The system for writing single-wavelength continuous weak grating based on real-time reflectivity monitoring according to claim 1 is characterized by: The position control accuracy of the precision 3D transmission platform (4) is ±1 μm, and supports continuous writing of more than 100 weak gratings on a single optical fiber.

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