Tunable pulse fiber laser
By combining pump lasers, beam combiners, high-reflective gratings, active fibers, low-reflective gratings and acousto-optical modulators, a resonant cavity is formed, which solves the problem of insufficient average output power of single-mode semiconductor laser diodes, and achieves efficient pulse width and frequency tunable 1550nm pulsed laser output to meet the needs of diversified applications.
Patent Information
- Application Number
- CN202422604666.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-10-28
AI Technical Summary
In the prior art, the average output power of single-mode semiconductor laser diodes is limited, and it is impossible to directly adjust the pulse width and frequency tunable pulse fiber laser amplification system seed source.
A combined structure of pump laser, beam combiner, high-reflective grating, active fiber, low-reflective grating and acousto-optical modulator is adopted to form a resonant cavity, and a pump laser is used to generate continuous light in the 1550nm band, and a 1550nm pulsed laser with a peak power of no less than 4W and a tunable pulse width and frequency through the acousto-optical modulator modulation is used to generate 1550nm pulsed laser with a peak power of no less than 4W and a tunable pulse width and frequency.
It realizes the compact optical path structure, simple structure, excellent output spectral performance, improves the output average power, pulse width and frequency tuning range of the pump laser, and can be directly adjusted into the seed source of the pulse width and frequency tunable pulse fiber laser amplification system.
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Figure CN223285423U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of laser technology, and more specifically, relates to a tunable pulse fiber laser. Background Art
[0002] Currently, pulsed lasers are mainly generated through active Q-switching or passive Q-switching technology to produce nanosecond and picosecond pulsed lasers. These technologies have disadvantages such as single output pulse width and limited tuning frequency range, and cannot meet the diverse application market needs.
[0003] Directly modulating the pulsed laser generated by a semiconductor laser diode can achieve a large frequency tuning range, and the pulse width is tunable, which can meet the needs of diversified application markets.
[0004] Of the single-mode semiconductor laser diodes currently available on the market, only those in the 1064nm band can achieve significant average power, typically several hundred milliwatts, which is sufficient for applications related to direct modulation and pulsed laser generation, such as serving as a seed source for MOPA fiber laser amplification systems. In the 1550nm band, only products with average power levels in the milliwatt range exist, which is too low to be directly modulated and used as a seed source. Utility Model Content
[0005] The purpose of the embodiments of the present application is to provide a tunable pulse fiber laser to solve the technical problem in the prior art that the single-mode semiconductor laser diode has a limited average output power and cannot be directly modulated as a seed source for a pulse width and frequency tunable pulse fiber laser amplification system.
[0006] To achieve the above objectives, the technical solution adopted in this application is to provide a tunable pulse fiber laser, comprising:
[0007] Pump laser;
[0008] a beam combiner, wherein a pump end of the beam combiner is connected to an output end of the pump laser;
[0009] a high-reflection grating, wherein an input end of the high-reflection grating is connected to an output end of the beam combiner;
[0010] an active optical fiber, one end of which is connected to the output end of the high-reflection grating;
[0011] a low-reflection grating, wherein an input end of the low-reflection grating is connected to the other end of the active optical fiber; and
[0012] An acousto-optic modulator, wherein the input end of the acousto-optic modulator is directly connected to the output end of the low-reflection grating.
[0013] Optionally, the pump laser is a pump laser diode, and the central wavelength of the pump laser diode is 915 nm.
[0014] Optionally, the output power of the pump laser diode is greater than 30 W, and the output fiber of the pump laser diode is 105 / 125-MM-0.22NA.
[0015] Optionally, the signal fiber of the combiner is 10 / 125-DCF-0.08NA, and the pump fiber of the combiner is 105 / 125-MM-0.22NA.
[0016] Optionally, the pump power of the beam combiner is greater than 30W, and the signal power of the beam combiner is greater than 10W.
[0017] Optionally, the central wavelength of the high-reflection grating is 1550 nm, the working bandwidth of the high-reflection grating is 10 nm, the reflectivity of the high-reflection grating is greater than 99.9%, and the optical fiber of the high-reflection grating is 10 / 125-DCF-0.08NA.
[0018] Optionally, the active optical fiber is a commercial erbium-ytterbium co-doped 10 / 125 double-clad optical fiber, and the length of the active optical fiber is determined according to the actual absorption coefficient of the optical fiber.
[0019] Optionally, the central wavelength of the low-reflection grating is 1550 nm, the working bandwidth of the low-reflection grating is 5 nm, the reflectivity of the low-reflection grating is 50%, and the optical fiber of the low-reflection grating is 10 / 125-DCF-0.08NA.
[0020] Optionally, the modulation frequency of the acousto-optic modulator is greater than 100 MHz, the rise time of the acousto-optic modulator is less than 10 ns, and the power handling capacity of the acousto-optic modulator is greater than 10 W.
[0021] Optionally, the central wavelength of the acousto-optic modulator is 1550 nm, the operating bandwidth of the acousto-optic modulator is 10 nm, and the input and output optical fibers of the acousto-optic modulator are 10 / 125-DCF-0.08NA.
[0022] The tunable pulse fiber laser provided by the present application has the following beneficial effects: compared with the prior art, the tunable pulse fiber laser provided by the present application has a compact optical path structure, a simple structure, and excellent output spectrum performance indicators; a high-reflection grating, an active optical fiber, and a low-reflection grating form a resonant cavity, and a pump laser is used to generate continuous light in the 1550nm band, with a line width of less than 5nm and an output power of 5W. After modulation by an acousto-optic modulator, a 1550nm pulse laser with a peak power of not less than 4W and tunable pulse width and frequency is generated, with a pulse width tuning range of 1-1000ns and a frequency tuning range of 1-40000kHz. The average output power of the pump laser and the tunable range of the pulse width and frequency are increased, and the pump laser can be directly modulated to serve as a seed source for a pulse width and frequency tunable pulse fiber laser amplification system. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0024] Figure 1 Schematic diagram of the structure of a tunable pulse fiber laser provided in an embodiment of the present application.
[0025] Among them, the reference numerals in the figures are:
[0026] 11-Pump laser;
[0027] 12- beam combiner;
[0028] 13-High reflective grating;
[0029] 14-active optical fiber;
[0030] 15- low reflection grating;
[0031] 16-Acousto-optic modulator. DETAILED DESCRIPTION
[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0033] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.
[0034] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.
[0036] See also Figure 1 The tunable pulse fiber laser provided in the embodiment of the present application is now described. The tunable pulse fiber laser includes a pump laser 11, a beam combiner 12, a high-reflection grating 13, an active fiber 14, a low-reflection grating 15, and an acousto-optic modulator 16. The pump end of the beam combiner 12 is connected to the output end of the pump laser 11; the input end of the high-reflection grating 13 is connected to the output end of the beam combiner 12; one end of the active fiber 14 is connected to the output end of the high-reflection grating 13; the input end of the low-reflection grating 15 is connected to the other end of the active fiber 14; and the input end of the acousto-optic modulator 16 is connected to the output end of the low-reflection grating 15.
[0037] The tunable pulse fiber laser provided in the embodiments of the present application has a compact and simple optical path structure and excellent output spectrum performance indicators compared to the prior art. A high-reflection grating, an active optical fiber, and a low-reflection grating form a resonant cavity. A pump laser is used to generate continuous light in the 1550nm band, with a line width of less than 5nm and an output power of 5W. After modulation by an acousto-optic modulator, a 1550nm pulse laser with a peak power of not less than 4W and tunable pulse width and frequency is generated. The pulse width tuning range is 1-1000ns, and the frequency tuning range is 1-40000kHz. The average output power of the pump laser and the tunable range of the pulse width and frequency are increased, and the pump laser can be directly modulated to serve as a seed source for the pulse width and frequency tunable pulse fiber laser amplification system.
[0038] In one embodiment of the present application, the pump laser 11 is a pump laser diode, the central wavelength of the pump laser diode is 915 nm, the output power of the pump laser diode is greater than 30 W, and the output fiber of the pump laser diode is 105 / 125-MM-0.22NA.
[0039] In this embodiment, the pump laser diode has an output power exceeding 30W, and its output fiber is a 105 / 125mm, 0.22NA fiber. The high power output and stable performance of the pump laser diode ensure high efficiency and reliability of the entire laser system. In practical applications, optimizing the coupling efficiency between the pump laser diode and the active fiber can further improve the laser conversion efficiency and reduce energy loss.
[0040] In one embodiment of the present application, the resonant cavity formed by the high-reflection grating, active optical fiber and low-reflection grating is an external cavity cladding pumping structure. External cavity pumping can reduce intracavity loss, improve signal-pump light conversion efficiency, and reduce energy consumption.
[0041] In one embodiment of the present application, the signal fiber of the combiner 12 is 10 / 125-DCF-0.08NA, and the pump fiber of the combiner 12 is 105 / 125-MM-0.22NA.
[0042] In this embodiment, the combiner is used to couple signal light and pump light into the core and cladding of the combiner's output optical fiber, respectively; wherein the signal light is transmitted in the core and the pump light is transmitted in the cladding, and is used to provide seed light and pump light to the optical fiber amplifier.
[0043] In one embodiment of the present application, the pump power of the combiner 12 is greater than 30W, and the signal power of the combiner 12 is greater than 10W.
[0044] In one embodiment of the present application, the central wavelength of the high-reflection grating 13 is 1550 nm, the working bandwidth of the high-reflection grating 13 is 10 nm, the reflectivity of the high-reflection grating 13 is greater than 99.9%, and the optical fiber of the high-reflection grating 13 is 10 / 125-DCF-0.08NA.
[0045] In this embodiment, the high-reflection grating 13 is a back-resonance mirror of the fiber laser resonator, and is used in conjunction with the low-reflection grating to form a resonant cavity. The central wavelength and operating bandwidth of the high-reflection grating 13 determine the central wavelength of the output signal light and limit the spectral linewidth.
[0046] In one embodiment of the present application, the active optical fiber 14 is a commercial Erbium-Ytterbium co-doped 10 / 125 double-clad optical fiber, and the length of the active optical fiber 14 is determined according to the actual absorption coefficient of the optical fiber.
[0047] In this embodiment, the commercial Erbium-Ytterbium co-doped 10 / 125 double-clad optical fiber has excellent performance in absorbing pump light and converting it into laser output due to its high doping concentration and high absorption coefficient.
[0048] In this embodiment, the length of the active optical fiber is carefully selected to provide a suitable absorption coefficient, which can meet the power output with high conversion efficiency and ensure that the laser remains stable under various operating conditions.
[0049] At the same time, thermal management is taken into consideration to avoid the problem of fiber performance degradation due to overheating. By precisely controlling the length and doping level of the active fiber, it meets the application requirements of high power and high stability.
[0050] In one embodiment of the present application, the central wavelength of the low-reflection grating 15 is 1550 nm, the working bandwidth of the low-reflection grating 15 is 5 nm, the reflectivity of the low-reflection grating 15 is 50%, and the optical fiber of the low-reflection grating 15 is 10 / 125-DCF-0.08NA.
[0051] In this embodiment, the low-reflection grating 15 is another key component of the resonant cavity. Its design allows some laser energy to escape, forming the output laser. The central wavelength of 1550nm matches the high-reflection grating 13, ensuring the stability of the laser output.
[0052] In this embodiment, the operating bandwidth of 5 nm is narrower than that of the high-reflection grating 13 , which helps to improve the monochromaticity of the output laser, thereby providing a purer laser source in certain applications.
[0053] In this embodiment, the design of a reflectivity of 50% not only ensures sufficient feedback to maintain laser oscillation, but also allows sufficient laser output to meet the output power requirements of different applications.
[0054] In this embodiment, the use of optical fiber 10 / 125-DCF-0.08NA ensures good coupling between the low-reflection grating 15 and the active optical fiber 14. Through these carefully designed components, the tunable pulse fiber laser of the present application can provide high-quality pulse laser output.
[0055] In one embodiment of the present application, the modulation frequency of the AOM 16 is greater than 100 MHz, the rise time of the AOM 16 is less than 10 ns, and the power handling capacity of the AOM 16 is greater than 10 W.
[0056] It can be understood that the AOM 16 is a device that modulates a light beam by utilizing the light diffraction effect generated when sound waves propagate in a medium.
[0057] The AOM 16 typically consists of a transparent acousto-optic medium, a transducer, and a control circuit. The transducer converts electrical signals into sound waves, which, when propagating through the medium, create periodic refractive index variations within the medium, causing the light beam passing through the medium to diffract.
[0058] In this embodiment, the AOM 16 modulates the laser beam by controlling the characteristics of the diffracted beam by varying the frequency and intensity of the electrical signal. In the tunable pulsed fiber laser of this application, the AOM is used to achieve high-speed modulation of the laser pulses to meet the pulse width and frequency requirements of different applications.
[0059] In this embodiment, the acousto-optic modulator (AOM) 16 is a key component for achieving laser pulse modulation. Its high-speed modulation capability is crucial for generating high-precision and high-repetition-rate pulsed lasers. A modulation frequency greater than 100 MHz enables a wide frequency tuning range, meeting the requirements of high-speed laser processing.
[0060] In this embodiment, the rise time of the AOM 16 is less than 10 ns. This fast response time ensures that narrow pulse width modulation can obtain a larger power output.
[0061] Furthermore, the AOM 16 can withstand power exceeding 10W, demonstrating that it maintains stable performance even with high-power continuous laser input and is not damaged by excessive power. Through these carefully designed parameters, the tunable pulsed fiber laser of this application is capable of providing highly stable and precise pulsed laser output.
[0062] In one embodiment of the present application, the central wavelength of the AOM 16 is 1550 nm, the operating bandwidth of the AOM 16 is 10 nm, and the input and output optical fibers of the AOM 16 are 10 / 125-DCF-0.08NA.
[0063] In this embodiment, the central wavelength of the AOM 16 (1550 nm) matches the central wavelengths of the high-reflection grating 13 and the low-reflection grating 15, ensuring efficient operation of the entire laser system at a specific wavelength.
[0064] In this embodiment, the design of a working bandwidth of 10 nm limits the line width of the output spectrum, thereby optimizing the spectrum.
[0065] In this embodiment, the use of 10 / 125-DCF-0.08NA input and output fibers ensures good coupling between the AOM and the rest of the system. Through these carefully designed parameters, the tunable pulsed fiber laser of this application can provide high stability and high precision pulsed laser output.
[0066] A tunable pulse fiber laser provided in an embodiment of the present application includes a pump laser, a beam combiner, a high-reflection grating, an active optical fiber, a low-reflection grating, and an acousto-optic modulator. The pump end of the beam combiner is connected to the output end of the pump laser; the input end of the high-reflection grating is connected to the output end of the beam combiner; one end of the active optical fiber is connected to the high-reflection grating, and the other end is connected to the low-reflection grating; the input end of the acousto-optic modulator is connected to the output end of the low-reflection grating.
[0067] In the embodiment of the present application, a high-reflection grating, an active optical fiber, and a low-reflection grating form a resonant cavity. A pump laser is used to generate continuous light in the 1550nm band, with a line width of less than 5nm and an output power of 5W. After modulation by an acousto-optic modulator, a 1550nm pulsed laser with a peak power of not less than 4W and tunable pulse width and frequency is generated. The pulse width tuning range is 1-1000ns, and the frequency tuning range is 1-40000kHz. This improves the output average power and the tunable range of pulse width and frequency.
[0068] The tunable pulse fiber laser provided in this embodiment has a compact optical path structure, a simple structure, and excellent output spectrum performance indicators. It is the industry's first 1550nm tunable pulse fiber laser with high peak power, tunable pulse width, and frequency. It is an ideal seed light source for MOPA pulse fiber laser amplification systems.
[0069] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.
Claims
1. A tunable pulse fiber laser, characterized in that: include: Pump laser (11); A beam combiner (12), wherein a pump end of the beam combiner (12) is connected to an output end of the pump laser (11); a high-reflection grating (13), wherein an input end of the high-reflection grating (13) is connected to an output end of the beam combiner (12); an active optical fiber (14), one end of the active optical fiber (14) being connected to the output end of the high-reflection grating (13); a low-reflection grating (15), wherein an input end of the low-reflection grating (15) is connected to the other end of the active optical fiber (14); as well as An acousto-optic modulator (16), wherein the input end of the acousto-optic modulator (16) is connected to the output end of the low-reflection grating (15).
2. The tunable pulse fiber laser according to claim 1, wherein: The pump laser (11) is a pump laser diode, and the central wavelength of the pump laser diode is 915 nm.
3. The tunable pulse fiber laser according to claim 2, wherein: The output power of the pump laser diode is greater than 30W, and the output optical fiber of the pump laser diode is 105 / 125-MM-0.22NA.
4. The tunable pulse fiber laser according to claim 1, wherein: The signal optical fiber of the beam combiner (12) is 10 / 125-DCF-0.08NA, and the pump optical fiber of the beam combiner (12) is 105 / 125-MM-0.22NA.
5. The tunable pulse fiber laser according to claim 4, wherein: The pump power of the beam combiner (12) is greater than 30W, and the signal power of the beam combiner (12) is greater than 10W.
6. The tunable pulse fiber laser according to claim 1, wherein: The central wavelength of the high-reflection grating (13) is 1550 nm, the working bandwidth of the high-reflection grating (13) is 10 nm, the reflectivity of the high-reflection grating (13) is greater than 99.9%, and the optical fiber of the high-reflection grating (13) is 10 / 125-DCF-0.08NA.
7. The tunable pulse fiber laser according to claim 1, wherein: The active optical fiber (14) is a commercial erbium-ytterbium co-doped 10 / 125 double-clad optical fiber, and the length of the active optical fiber (14) is determined according to the actual absorption coefficient of the optical fiber.
8. The tunable pulse fiber laser according to claim 1, wherein: The central wavelength of the low-reflection grating (15) is 1550 nm, the working bandwidth of the low-reflection grating (15) is 5 nm, the reflectivity of the low-reflection grating (15) is 50%, and the optical fiber of the low-reflection grating (15) is 10 / 125-DCF-0.08NA.
9. The tunable pulse fiber laser according to any one of claims 1 to 8, wherein: The modulation frequency of the acousto-optic modulator (16) is greater than 100 MHz, the rise time of the acousto-optic modulator (16) is less than 10 ns, and the power handling capacity of the acousto-optic modulator (16) is greater than 10 W.
10. The tunable pulse fiber laser according to claim 9, wherein: The central wavelength of the acousto-optic modulator (16) is 1550 nm, the working bandwidth of the acousto-optic modulator (16) is 10 nm, and the input and output optical fibers of the acousto-optic modulator (16) are 10 / 125-DCF-0.08NA.