Nanosecond pulse fiber laser for efficient marking

Abstract

The utility model provides a nanosecond pulse fiber laser for efficient marking. The nanosecond pulse fiber laser comprises a seed source module part, a primary amplification module part, a secondary amplification module part and an output isolator, the first-stage amplification module part and the second-stage amplification module part both employ a cladding pumping MOPA structure to amplify signal light; and each stage of amplification module adopts a commercial ytterbium-doped double-clad optical fiber. According to the nanosecond pulse fiber laser for efficient marking, through reasonable output waveform design, more suitable optical path model selection and optimized gain distribution, it is kept that each stage of fiber amplifier has a good output spectrum, through amplification of the two stages of amplifiers, the average power of 300 W, the peak power larger than 7 kW, the monopulse energy larger than 0.5 mJ and the frequency range of 1-70000 kHz are achieved, and the nanosecond pulse fiber laser for efficient marking is suitable for high-efficiency marking. And nanosecond pulse laser output with high repetition frequency, high power and high beam quality is realized.

Description

Technical Field

[0001] The present application belongs to the field of laser technology, and more specifically, relates to a nanosecond pulse fiber laser for efficient marking. Background Art

[0002] Nanosecond pulsed fiber lasers are rapidly developing due to their excellent output beam quality, compact structure, high flexibility, high reliability, and maintenance-free operation. Currently, the main methods for generating nanosecond pulsed fiber lasers include Q-switching, directly modulating semiconductor laser diodes, and using MOPA technology to achieve target performance through multiple fiber amplifier stages.

[0003] Nanosecond pulse lasers generated by combining Q-switching technology with MOPA technology have disadvantages such as single output pulse width and limited tuning frequency range, and cannot meet the diverse application market needs.

[0004] However, the average output power of existing nanosecond pulse fiber lasers is limited. The highest average power output of similar lasers is less than 100W, resulting in low laser application processing efficiency. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a nanosecond pulse fiber laser for efficient marking, so as to solve the technical problems in the prior art that the average output power of the existing nanosecond pulse fiber laser for efficient marking is limited, the highest average power output of similar lasers is less than 100W, and the laser application processing efficiency is low.

[0006] To achieve the above objectives, the technical solution adopted in this application is: to provide a nanosecond pulse fiber laser for high-efficiency marking, comprising a seed source module, a first-stage amplification module, a second-stage amplification module, and an output isolator; the seed source module comprises a directly modulated semiconductor laser diode and a first online isolator connected in sequence;

[0007] The first-stage amplification module includes a first pump laser, a first beam combiner, a first ytterbium-doped double-clad optical fiber, and a second in-line isolator connected in sequence; the output end of the first in-line isolator is connected to the signal end of the first beam combiner, and the output end of the first pump laser is connected to the pump end of the first beam combiner;

[0008] The secondary amplification module includes a second pump laser, and a mode field adapter, a second ytterbium-doped double-clad optical fiber, and a second beam combiner connected in sequence; the pump end of the second beam combiner is connected to the second pump laser;

[0009] The output isolator is connected to the signal optical fiber of the second combiner.

[0010] Optionally, the directly modulated semiconductor laser diode is a commercial SLD semiconductor laser diode with a central wavelength of 1064 nm, a line width less than 15 nm, an output fiber of Hi1060 fiber, a pulse output state, a pulse width range of 10-350 ns, and a repetition frequency of 1-70000 kHz.

[0011] Optionally, the first in-line isolator has a central wavelength of 1059 nm, an operating bandwidth of 16 nm, an input optical fiber of Hi1060 optical fiber, an output optical fiber of 10 / 125 single-clad optical fiber, an average power tolerance of 300 mW, an insertion loss of less than 3 dB, and an isolation greater than 25 dB;

[0012] The central wavelength of the second online isolator is 1062nm, the working bandwidth is 20nm, the input fiber is 10 / 125 single-clad fiber, the output fiber is 10 / 125 single-clad fiber, the average power it can withstand is 20W, the insertion loss is less than 1.5dB, and the isolation is greater than 25dB.

[0013] Optionally, the first pump laser provides pump excitation to the first ytterbium-doped double-clad optical fiber, has an output power greater than 30 W, a central wavelength of 915 nm, and an output optical fiber that is a 105 / 125 multimode optical fiber;

[0014] The second pump laser provides pump excitation for the second ytterbium-doped double-clad optical fiber, has an output power greater than 300 W, a central wavelength of 976 nm, and an output optical fiber that is a 200 / 220 multimode optical fiber.

[0015] Optionally, the signal fiber of the first combiner is a 10 / 125 double-clad fiber, the pump fiber is a 105 / 125 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 10W, and the pump light withstand power is greater than 30W.

[0016] Optionally, the signal fiber of the second combiner is a 20 / 250 double-clad fiber, the pump fiber is a 200 / 220 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 300W, and the pump light withstand power is greater than 300W.

[0017] Optionally, the first ytterbium-doped double-clad optical fiber is a commercial ytterbium-doped 10 / 125 double-clad optical fiber, and the length of the optical fiber is determined according to the actual absorption coefficient of the optical fiber.

[0018] Optionally, the second ytterbium-doped double-clad optical fiber is a commercial ytterbium-doped 20 / 250 double-clad optical fiber, and the length of the optical fiber is determined according to the actual absorption coefficient of the optical fiber.

[0019] Optionally, the input end of the mode field adapter is a 10 / 125 single-clad optical fiber, and the output end is a 20 / 250 double-clad optical fiber, and can withstand an average power greater than 20W.

[0020] Optionally, the operating wavelength of the output isolator is 1064 nm, and the input optical fiber is a 20 / 250 double-clad optical fiber, wherein the average power it can withstand is greater than 300 W, the peak power it can withstand is greater than 7 kW, and the isolation is greater than 25 dB.

[0021] The beneficial effects of the high-efficiency nanosecond pulse fiber laser for marking provided by the present application are as follows: compared with the existing technology, the high-efficiency nanosecond pulse fiber laser for marking provided by the present application utilizes a reasonably designed output waveform, a more appropriate optical path selection, and an optimized gain distribution to maintain a good output spectrum for each stage of the optical fiber amplifier. After amplification by two stages of amplifiers, it achieves an average power of 300W, a peak power greater than 7kW, a single pulse energy greater than 0.5mJ, a frequency range of 1-70000kHz, and realizes nanosecond pulse laser output with high repetition rate, high power, and high beam quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 This is a schematic structural diagram of a nanosecond pulse fiber laser for high-efficiency marking provided in an embodiment of the present application.

[0024] Among them, the reference numerals in the figures are:

[0025] 1-seed source module; 11-directly modulated semiconductor laser diode; 12-first online isolator;

[0026] 2-first stage amplification module; 21-first pump laser; 22-first beam combiner; 23-first ytterbium-doped double-clad fiber; 24-second in-line isolator; 25-coupler; 26-fiber-coupled photodetector;

[0027] 3-secondary amplification module; 31-mode field adapter; 32-second ytterbium-doped double-clad fiber; 33-second beam combiner; 34-second pump laser;

[0028] 41-Output isolator. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] See also Figure 1 The nanosecond pulse fiber laser for high-efficiency marking provided by the embodiment of the present application is now described. The nanosecond pulse fiber laser for high-efficiency marking includes a seed source module 1, a first-stage amplification module 2, a second-stage amplification module 3, and an output isolator 41.

[0034] The seed source module part 1 includes a directly modulated semiconductor laser diode 11 and a first online isolator 12 connected in sequence.

[0035] The first-stage amplification module part 2 includes a first pump laser 21, and a first combiner 22, a first ytterbium-doped double-clad fiber 23, and a second in-line isolator 24 connected in sequence; the output end of the first in-line isolator 12 is connected to the signal end of the first combiner 22, and the output end of the first pump laser 21 is connected to the pump end of the first combiner 22.

[0036] The secondary amplification module part 3 includes a second pump laser 34, and a mode field adapter 31, a second ytterbium-doped double-clad fiber 32, and a second combiner 33 connected in sequence; the pump end of the second combiner 33 is connected to the second pump laser 34; and the output isolator 41 is connected to the signal fiber of the second combiner 33.

[0037] The high-efficiency nanosecond pulse fiber laser for marking provided in the present application, compared with the prior art, utilizes a reasonably designed output waveform, a more appropriate optical path selection, and optimized gain distribution to maintain a good output spectrum for each stage of the fiber amplifier. After two-stage amplification, it achieves an average power of 300W, a peak power greater than 7kW, a single pulse energy greater than 0.5mJ, and a frequency range of 1-70000kHz, thereby achieving nanosecond pulse laser output with high repetition rate, high power, and high beam quality.

[0038] In one embodiment of the present application, the directly modulated semiconductor laser diode 11 is a commercial SLD semiconductor laser diode with a central wavelength of 1064 nm, a line width less than 15 nm, an output fiber of Hi1060 fiber, an output state of pulses, a pulse width range of 10-350 ns, and a repetition frequency of 1-70000 kHz.

[0039] In the embodiment of the present application, the directly modulated semiconductor laser diode 11 is used to provide seed light for the laser. The directly modulated semiconductor laser diode 11 adopts a commercial SLD semiconductor laser diode with a total of 28 pulse widths to choose from.

[0040] In one embodiment of the present application, the first in-line isolator 12 has a central wavelength of 1059 nm, an operating bandwidth of 16 nm, an input fiber of Hi1060 fiber, an output fiber of 10 / 125 single-clad fiber, an average power tolerance of 300 mW, an insertion loss of less than 3 dB, and an isolation greater than 25 dB; the second in-line isolator 24 has a central wavelength of 1062 nm, an operating bandwidth of 20 nm, an input fiber of 10 / 125 single-clad fiber, an output fiber of 10 / 125 single-clad fiber, an average power tolerance of 20 W, an insertion loss of less than 1.5 dB, and an isolation greater than 25 dB.

[0041] In this embodiment, the inline isolator optically isolates the return light at the isolator's output, protecting the stable operation of the entire fiber laser system. The inline isolator also integrates a bandpass filter to optimize the output spectral linewidth; a mode field adapter enables the transition of optical signals from thin to thick fiber without degrading beam quality. The isolator's power handling capacity is selected based on the input power.

[0042] In one embodiment of the present application, the first pump laser 21 provides pump excitation to the first ytterbium-doped double-clad fiber 23, with an output power greater than 30 W, a central wavelength of 915 nm, and the output fiber is a 105 / 125 multimode fiber; the second pump laser 34 provides pump excitation to the second ytterbium-doped double-clad fiber 32, with an output power greater than 300 W, a central wavelength of 976 nm, and the output fiber is a 200 / 220 multimode fiber.

[0043] In this embodiment, the pump wavelength determines the pump absorption coefficient of the active fiber. For design considerations, a 915 nm pump source is sufficient for the first pump laser 21. A 976 nm pump source is used for the second pump laser 34 to maximize the pump absorption coefficient, optimize the second-stage optical path structure, and achieve optimal optical performance indicators.

[0044] In one embodiment of the present application, the signal fiber of the first combiner 22 is a 10 / 125 double-clad fiber, the pump fiber is a 105 / 125 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 10W, and the pump light withstand power is greater than 30W.

[0045] In one embodiment of the present application, the signal fiber of the second combiner 33 is a 20 / 250 double-clad fiber, the pump fiber is a 200 / 220 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 300W, and the pump light withstand power is greater than 300W.

[0046] In this embodiment, the first combiner 22 uses a 10 / 125 double-clad fiber as the signal fiber, ensuring efficient and stable signal light transmission. Simultaneously, the use of a 105 / 125 multimode fiber as the pump fiber not only increases the pump light coupling efficiency to over 95%, but also enables the pump light to fully excite the gain medium in the ytterbium-doped double-clad fiber, thereby increasing the overall output power of the laser. Furthermore, the high-power handling design of both the signal and pump light ensures the stability and reliability of the laser under high-intensity operating conditions.

[0047] The second combiner 33 uses 20 / 250 double-clad fiber as its signal fiber, a choice designed to accommodate higher-power laser transmission requirements. Similarly, 200 / 220 multimode fiber is used as the pump fiber, ensuring efficient coupling of the pump light and further improving its absorption efficiency. With a pump light coupling efficiency of up to 95% and a power handling capability exceeding 300W for both signal and pump light, the second-stage optical path structure fully leverages its performance advantages, providing stable and efficient optical output for the entire laser system.

[0048] In one embodiment of the present application, the first ytterbium-doped double-clad optical fiber 23 is a commercial ytterbium-doped 10 / 125 double-clad optical fiber, and the length of the optical fiber is determined according to the actual absorption coefficient of the optical fiber.

[0049] In one embodiment of the present application, the second ytterbium-doped double-clad optical fiber 32 is a commercial ytterbium-doped 20 / 250 double-clad optical fiber, and the length of the optical fiber is determined according to the actual absorption coefficient of the optical fiber.

[0050] In this embodiment, the first ytterbium-doped double-clad fiber 23 was selected not only for its commercial maturity and stability, but also for its suitable size and performance parameters to ensure efficient operation of the laser system. Precisely setting the fiber length relies on in-depth research and precise measurement of the fiber's actual absorption coefficient, a step crucial for achieving efficient laser energy conversion.

[0051] Similarly, the selection of the second ytterbium-doped double-clad fiber 32 was based on its stability and performance advantages under high-power pumping conditions. Commercial ytterbium-doped 20 / 250 double-clad fiber was chosen not only for its larger core and cladding diameters, enabling it to carry higher pump and signal powers, but also because its fiber length was carefully calculated to ensure that the actual absorption coefficient of the fiber matched the system design requirements.

[0052] In one embodiment of the present application, the input end of the mode field adapter 31 is a 10 / 125 single-clad optical fiber, and the output end is a 20 / 250 double-clad optical fiber, and the average power it withstands is greater than 20W.

[0053] In this embodiment, the main function of the mode field adapter 31 is to achieve efficient transmission of signal light from the first combiner 22 to the second ytterbium-doped double-clad fiber 32. Its design takes into account the matching of fiber modes to ensure that the signal light has minimal loss during transmission. In addition, the high power handling capability of the mode field adapter 31 also ensures its stability and reliability in high-power fiber lasers. By selecting a 10 / 125 single-clad fiber as the input end, which matches the signal fiber of the first combiner 22, and using a 20 / 250 double-clad fiber as the output end, which matches the second ytterbium-doped double-clad fiber 32, this design ensures smooth signal transmission while taking into account the overall performance of the system.

[0054] In one embodiment of the present application, the operating wavelength of the output isolator 41 is 1064 nm, the input optical fiber is a 20 / 250 double-clad optical fiber, the average power it can withstand is greater than 300 W, the peak power it can withstand is greater than 7 kW, and the isolation is greater than 25 dB.

[0055] In this embodiment, the design of the output isolator 41 ensures that the laser has excellent performance at the output end. Its operating wavelength is set to 1064nm, which is one of the commonly used wavelengths in fiber lasers and is suitable for a variety of industrial applications. The input fiber adopts 20 / 250 double-clad fiber. This fiber structure can carry higher power and meet the needs of high-power output of the laser. At the same time, the isolator can withstand an average power of more than 300W and a peak power of up to 7kW, which shows its excellent power handling capability. In addition, the isolation is greater than 25dB, which effectively prevents the reflected light from damaging the internal components of the laser and improves the stability and reliability of the laser.

[0056] In this embodiment of the present application, both the first-stage amplifier module 2 and the second-stage amplifier module 3 employ a cladding-pumped MOPA structure to amplify the signal light. In this embodiment, each amplifier module utilizes commercial ytterbium-doped double-clad fiber, and the pump light source utilizes a 915nm and 976nm multimode semiconductor laser. Using a two-stage amplification structure, the seed source power is amplified to an average power of 300W, a peak power greater than 7kW, a single pulse energy greater than 0.5mJ, and a frequency range of 1-70,000kHz, achieving nanosecond pulse laser output with high repetition rate, high power, and high beam quality.

[0057] The nanosecond pulse fiber laser for high-efficiency marking provided in the embodiments of the present application has a compact optical path structure, a simple structure, and excellent output beam quality. It is the first nanosecond pulse fiber laser in the industry that can achieve a maximum single pulse energy of 0.5mJ and an average power output greater than 300W. It is an ideal light source for high-efficiency laser marking applications.

[0058] 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 nanosecond pulse fiber laser for high-efficiency marking, characterized in that: include: A seed source module part (1), the seed source module part (1) comprising a directly modulated semiconductor laser diode (11) and a first online isolator (12) connected in sequence; A first-stage amplification module part (2), the first-stage amplification module part (2) includes a first pump laser (21), and a first beam combiner (22), a first ytterbium-doped double-clad optical fiber (23), and a second online isolator (24) connected in sequence; the output end of the first online isolator (12) is connected to the signal end of the first beam combiner (22), and the output end of the first pump laser (21) is connected to the pump end of the first beam combiner (22); A secondary amplification module part (3), the secondary amplification module part (3) comprising a second pump laser (34), and a mode field adapter (31), a second ytterbium-doped double-clad optical fiber (32), and a second beam combiner (33) connected in sequence; a pump end of the second beam combiner (33) is connected to the second pump laser (34); An output isolator (41); the output isolator (41) is connected to the signal optical fiber of the second combiner (33).

2. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The directly modulated semiconductor laser diode (11) is a commercial SLD semiconductor laser diode with a central wavelength of 1064nm and a line width of less than 15nm. The output optical fiber is Hi1060 optical fiber, the output state is pulse, the pulse width range is 10-350ns, and the repetition frequency is 1-70000kHz.

3. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The first online isolator (12) has a central wavelength of 1059 nm, an operating bandwidth of 16 nm, an input optical fiber of Hi1060 optical fiber, an output optical fiber of 10 / 125 single-clad optical fiber, an average power tolerance of 300 mW, an insertion loss of less than 3 dB, and an isolation greater than 25 dB; The central wavelength of the second online isolator (24) is 1062nm, the working bandwidth is 20nm, the input optical fiber is 10 / 125 single-clad optical fiber, the output optical fiber is 10 / 125 single-clad optical fiber, the average power is 20W, the insertion loss is less than 1.5dB, and the isolation is greater than 25dB.

4. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The first pump laser (21) provides pump excitation to the first ytterbium-doped double-clad optical fiber (23), the output power is greater than 30W, the central wavelength is 915nm, and the output optical fiber is a 105 / 125 multimode optical fiber; The second pump laser (34) provides pump excitation for the second ytterbium-doped double-clad optical fiber (32), has an output power greater than 300W, a central wavelength of 976nm, and an output optical fiber that is a 200 / 220 multimode optical fiber.

5. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The signal fiber of the first combiner (22) is a 10 / 125 double-clad fiber, the pump fiber is a 105 / 125 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 10W, and the pump light withstand power is greater than 30W.

6. The nanosecond pulse fiber laser for high-efficiency marking according to claim 5, characterized in that: The signal fiber of the second combiner (33) is a 20 / 250 double-clad fiber, the pump fiber is a 200 / 220 multimode fiber, the pump light coupling efficiency is greater than 95%, the signal light withstand power is greater than 300W, and the pump light withstand power is greater than 300W.

7. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The first ytterbium-doped double-clad optical fiber (23) is a commercial ytterbium-doped 10 / 125 double-clad optical fiber, and the length of the optical fiber is determined according to the actual absorption coefficient of the optical fiber.

8. The nanosecond pulse fiber laser for high-efficiency marking according to claim 7, characterized in that: The second ytterbium-doped double-clad optical fiber (32) is a commercial ytterbium-doped 20 / 250 double-clad optical fiber, and the optical fiber length is determined according to the actual absorption coefficient of the optical fiber.

9. The nanosecond pulse fiber laser for high-efficiency marking according to claim 1, characterized in that: The input end of the mode field adapter (31) is a 10 / 125 single-clad optical fiber, and the output end is a 20 / 250 double-clad optical fiber, and can withstand an average power greater than 20W.

10. The nanosecond pulse fiber laser for high-efficiency marking according to any one of claims 1 to 9, characterized in that: The output isolator (41) has an operating wavelength of 1064 nm, an input optical fiber of 20 / 250 double-clad optical fiber, an average power of more than 300 W, a peak power of more than 7 kW, and an isolation of more than 25 dB.

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