Power correction method of fiber laser

Abstract

The invention relates to a power correction method of an optical fiber laser, which comprises the following steps of: setting output power of the laser, and obtaining a power simulation curve; the laser is operated, N measured values of the output power of the laser are obtained, a power sampling curve is generated, and N is larger than or equal to 10; acquiring a power difference value between the power simulation curve and the power sampling curve; acquiring the compensation gain of the output power according to the power difference value; selecting a compensation mode according to the compensation gain; and correcting the working condition of the fiber laser according to the selected compensation mode so as to correct the output power of the fiber laser and reduce the error between the set power and the actual output power. Before long-term operation of the fiber laser, the deviation of the output power can be accurately identified, the working condition of the laser is correspondingly adjusted according to the compensation gain calculated by the power difference value, the method is executed regularly or as required, and the power of the fiber laser is stable after correction. The output power fluctuation caused by the influence of real-time factors such as return light and pump light in the optical fiber is avoided, and the method can correct the power of the optical fiber laser more accurately, stably and reliably.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber lasers, and in particular to a power correction method for optical fiber lasers. Background Art

[0002] In fiber lasers, due to the nonlinear characteristics of the pump source and the inconsistency of the fiber conversion efficiency, it is often impossible to achieve accurate linear power output by controlling the pump source only by linear current, resulting in a large deviation between the set power and the actual output optical power. In addition, due to the differences in optical fibers and pump sources, the produced machines are very different. When the same power is set, the output power varies greatly and the error is not fixed. For example, when the laser output power is set to 1000W, the actual output power of some lasers may be only 900W or even lower. At present, the power correction technology of fiber lasers in the market mostly relies on real-time power feedback. However, this method has encountered many challenges in practical applications. Due to the complex optical environment inside the fiber laser and the application terminal, such as material reflection, darkening caused by fiber aging, stray light, fiber cladding light, temperature changes and other factors, the detection accuracy and precision of the photodiode sensor or thermistor used for real-time feedback are seriously affected. These interferences make it difficult for the sensor to accurately capture the effective optical power data in the optical fiber. The reflected light and pump light inside the optical fiber will further interfere with the accuracy of the collected data. Therefore, the method based on real-time power feedback often leads to unstable optical power output and fluctuation of feedback reference in practical applications, thus affecting the performance of stable power output of fiber laser.

[0003] In order to solve this problem, a stable and effective optical power compensation method is urgently needed to improve the output power accuracy and stability of the fiber laser, ensure the consistency between the set power and the actual output power, and make end-customer applications easier and more stable. Summary of the invention

[0004] Based on this, in order to solve the above problems, the present invention provides a power correction method for a fiber laser, which greatly improves the stability of the laser output power and ensures that the set power is consistent with the actual output power.

[0005] To achieve the above-mentioned purpose, the present invention provides a power correction method for a fiber laser, comprising the following steps: setting the output power of the laser and obtaining a power simulation curve; running the laser, obtaining N measurement values ​​of the output power of the laser, and generating a power sampling curve, wherein N≥10; obtaining the power difference between the power simulation curve and the power sampling curve; obtaining a compensation gain of the output power according to the power difference; selecting a compensation method according to the compensation gain; and correcting the working conditions of the fiber laser according to the selected compensation method to correct the output power of the fiber laser.

[0006] In one embodiment, the compensation method includes at least one of correcting the current of the pump source, correcting the fiber parameters, and adjusting the internal temperature of the fiber laser.

[0007] In one of the embodiments, the step of obtaining the compensation gain of the output power according to the power difference includes obtaining the compensation gain by using one of a polynomial, an exponential function, a logarithmic function, and a power function.

[0008] In one of the embodiments, after the step of obtaining the compensation gain of the output power according to the power difference, the step further includes: performing statistical analysis based on the output power compensation gain, and triggering a graded warning signal when the compensation gain exceeds a threshold.

[0009] In one embodiment, the graded warning signal includes: a first-level warning signal, adjusting the internal temperature of the fiber laser according to the first-level warning signal; a second-level warning signal, correcting the fiber parameters according to the second-level warning signal; a third-level warning signal, correcting the current of the pump source according to the third-level warning signal; a fourth-level warning signal, correcting at least two of the current of the pump source, correcting the fiber parameters, and adjusting the internal temperature of the fiber laser according to the fourth-level warning signal; a fifth-level warning signal, correcting the current of the pump source, correcting the fiber parameters, and adjusting the internal temperature of the fiber laser according to the fifth-level warning signal.

[0010] In one embodiment, correcting the optical fiber parameters includes changing any one of the refractive index, length or shape of the optical fiber.

[0011] In one of the embodiments, the method further includes the steps of: obtaining the ambient temperature, and obtaining a first correction gain of the laser output power according to the ambient temperature.

[0012] In one of the embodiments, the method further includes the steps of: obtaining the ambient humidity, and obtaining a second correction gain of the laser output power according to the ambient humidity.

[0013] In one of the embodiments, the method further includes the steps of: obtaining the ambient air pressure, and obtaining a third correction gain of the laser output power according to the ambient air pressure.

[0014] In one of the embodiments, the method further includes the steps of: obtaining ambient temperature, humidity and air pressure, and obtaining a fourth correction gain of the laser output power according to the ambient temperature, humidity and air pressure.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a power correction method for a fiber laser. Before the fiber laser is operated for a long time, multiple measurement values ​​of the laser output power are obtained and a power sampling curve is generated. The curve is then compared with the set power, so that the output power deviation can be accurately identified. Then, the working conditions of the laser are adjusted accordingly based on the compensation gain calculated according to the power difference, which significantly improves the stability of the laser output power. The method is performed regularly or on demand to ensure that the laser maintains optimal performance during long-term use and prolong its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a schematic diagram of the working process of a method for power correction of a fiber laser.

[0017] Figure 2 It is a schematic diagram of output power comparison before adopting a power correction method of a fiber laser of the present invention.

[0018] Figure 3 It is a schematic diagram of the output power effect after adopting a power correction method of a fiber laser of the present invention. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0020] like Figure 1 As shown, this embodiment provides a power correction method for a fiber laser, comprising the following steps: setting the output power of the laser and obtaining a power simulation curve; running the laser, obtaining N measurement values ​​of the output power of the laser using a power meter, and generating a power sampling curve, wherein N ≥ 10, and the number of power measurement values ​​obtained can be 15, 20, 25, 30, 35, 40, 50, 80, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 or even more; obtaining a power difference P between the power simulation curve and the power sampling curve. df ; Obtain the output power compensation gain P according to the power difference cp ; According to the compensation gain P cpSelect a compensation method; correct the working conditions of the fiber laser according to the selected compensation method to correct the output power of the fiber laser. This embodiment provides a power correction method for a fiber laser. Before the fiber laser is operated for a long time, such as before leaving the factory, before use, or when it is shut down for maintenance during long-term operation, multiple measured values ​​of the laser output power are obtained and a power sampling curve is generated, which is then compared with the power simulation curve. The deviation of the output power can be accurately identified, and then the compensation gain calculated based on the power difference is used to adjust the working conditions of the laser accordingly, which significantly improves the stability of the laser output power. The consistency between the set power and the actual output power is improved. Regularly or on-demand execution of the method can ensure that the laser maintains optimal performance during long-term use and extend its service life. The power correction method for a fiber laser in this embodiment does not belong to real-time power monitoring and feedback. During the correction process, the negative impact of the return light and pump light in the optical fiber on the accuracy of the collected data is effectively shielded. After the correction, the power of the running fiber laser is stable, and the output power will not fluctuate due to the influence of real-time factors such as the return light and pump light in the optical fiber. The defects of the real-time power feedback method, such as low accuracy, large environmental impact, and power fluctuation, are overcome. The correction of the output power of the fiber laser is more accurate, stable and reliable, ensuring that the output power is consistent with the set power.

[0021] In one embodiment, the compensation method includes at least one of correcting the current of the pump source, correcting the fiber parameters, and adjusting the internal temperature of the fiber laser.

[0022] In one embodiment, the step of obtaining the compensation gain of the output power according to the power difference includes obtaining the compensation gain using a polynomial. For example, the formula y=k n x n + k n-1 x n-1 +k n-2 x n-2 +k n-3 x n-3 ......+ k1x+ k0 to obtain the compensation gain, where k0 to k nis a preset parameter, x is any one of the current control input, the refractive index of the optical fiber, the length of the optical fiber or the internal temperature of the optical fiber laser, and y is the target output power value. By way of example, the compensation gain can also be obtained by using one of the exponential function, the logarithmic function, and the power function. Table 1 is a comparison table of the measured values ​​before and after the power correction of the optical fiber laser using the power correction method of the optical fiber laser provided in the embodiment. It can be seen from Table 1 that the error between the set power before correction and the actual output power measurement value is as high as 63.69%. The power measurement value after processing using the power correction method of the optical fiber laser provided in this embodiment is basically equivalent to the set power value, with a maximum error of 0.59%, achieving accurate optical power correction. This method can improve the stability of the optical fiber laser and the accuracy of the output power, and is suitable for various application scenarios. Figure 2 The comparison of the output power measurement of the fiber laser before power correction is shown. Figure 2 It can be seen that there is a large error between the output power before correction and the set power; Figure 3 It is demonstrated that after using a power correction method for a fiber laser of this embodiment, the output power measurement value and the set power curves are basically coincident, the output power of the fiber laser is significantly improved, and the performance of the fiber laser is greatly optimized.

[0023] Table 1 Comparison of measured values ​​of fiber laser power before and after correction (Note: Error = (set power - measured power) ÷ set power × 100%) In one embodiment, according to the power difference P df Get the compensation gain P of the output power cp The step further includes: compensating the gain P according to the output power cp For statistical analysis, when the compensation gain P cp When the threshold is exceeded, a graded warning signal is triggered. The graded warning signal includes: a first-level warning signal, according to which the internal temperature of the fiber laser is adjusted; a second-level warning signal, according to which the fiber parameters are corrected; a third-level warning signal, according to which the current of the pump source is corrected; a fourth-level warning signal, according to which at least two of the current of the pump source, the fiber parameters, and the internal temperature of the fiber laser are corrected; a fifth-level warning signal, according to which the current of the pump source, the fiber parameters, and the internal temperature of the fiber laser are corrected. Specifically, the power compensation gain P cp Compare with the preset data mapping table, when A1≤P cp <A2, trigger the first-level warning signal; when A2≤P cp <A3, trigger the second level warning signal; when A3≤P cp<A4, trigger the third-level warning signal; when A4≤P cp <A5, trigger the fourth level warning signal; when A5≤P cp <A6, a level 5 warning signal is triggered; when A6≤P cp When the alarm signal is triggered, the machine will be shut down for maintenance. Among them, A1<A2<A3<A4<A5<A6. This embodiment adopts a graded warning and alarm method to provide clear and targeted guidance for the output power optimization of the fiber laser. For different levels of warning signals, users can quickly identify and take appropriate compensation methods to correct the working conditions of the fiber laser, which significantly improves the accuracy and efficiency of power compensation.

[0024] In one embodiment, correcting the optical fiber parameters includes changing any one of the refractive index, length or shape of the optical fiber.

[0025] In one embodiment, a method for correcting the power of a fiber laser further includes the steps of: obtaining the ambient temperature, and obtaining a first correction gain g1 of the laser output power according to the ambient temperature, wherein y1= g 1+ y.

[0026] In one embodiment, a method for correcting the power of a fiber laser further includes the steps of: obtaining the ambient humidity, and obtaining a second correction gain g2 of the laser output power according to the ambient humidity, wherein y2= g 2+ y.

[0027] In one embodiment, a method for correcting the power of a fiber laser further includes the steps of: obtaining the ambient air pressure, and obtaining a third correction gain g3 of the laser output power according to the ambient air pressure, wherein y3= g 3+ y.

[0028] In one embodiment, the method further includes the following steps: a method for correcting the power of a fiber laser, obtaining the ambient temperature, humidity and air pressure, and obtaining a fourth correction gain of the laser output power according to the ambient temperature, humidity and air pressure. At this time, y4=g 1+ g 2+ g 3+ y.

[0029] The present invention provides a power correction method for a fiber laser, which can improve the stability of the output power of the fiber laser, enhance the long-term operation reliability, provide flexible and diverse compensation methods, introduce a graded early warning and alarm mechanism, etc., thereby promoting the optimization and improvement of the performance of the fiber laser.

[0030] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0031] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for correcting the power of a fiber laser, characterized in that: The following steps are involved: Set the laser output power and obtain the power simulation curve; Run the laser, obtain N measured values ​​of the laser output power, and generate a power sampling curve, where N ≥ 10; Obtain the power difference between the power simulation curve and the power sampling curve; Obtaining a compensation gain of the output power according to the power difference; Select compensation method according to compensation gain; The working condition of the fiber laser is corrected according to the selected compensation method to correct the output power of the fiber laser.

2. The method for correcting the power of a fiber laser according to claim 1, characterized in that: The compensation method includes at least one of correcting the current of the pump source, correcting the optical fiber parameters, and adjusting the internal temperature of the optical fiber laser.

3. The method for power correction of a fiber laser according to claim 1, characterized in that: The step of obtaining the compensation gain of the output power according to the power difference includes obtaining the compensation gain by using one of a polynomial, an exponential function, a logarithmic function, and a power function.

4. The method for power correction of a fiber laser according to claim 1, characterized in that: After the step of obtaining the compensation gain of the output power according to the power difference, the method further includes: performing statistical analysis according to the output power compensation gain, and triggering a graded warning signal when the compensation gain exceeds a threshold.

5. The method for correcting the power of a fiber laser according to claim 4, characterized in that: The graded warning signals include: a first-level warning signal, according to which the internal temperature of the fiber laser is adjusted; a second-level warning signal, according to which the fiber parameters are corrected; a third-level warning signal, according to which the current of the pump source is corrected; a fourth-level warning signal, according to which at least two of the current of the pump source, the fiber parameters, and the internal temperature of the fiber laser are corrected; and a fifth-level warning signal, according to which the current of the pump source, the fiber parameters, and the internal temperature of the fiber laser are corrected.

6. A method for correcting the power of a fiber laser according to claim 2 or 5, characterized in that: Correcting fiber parameters includes changing any of the fiber's refractive index, length or shape.

7. The method for correcting the power of a fiber laser according to claim 1, characterized in that: The method also includes the steps of: obtaining the ambient temperature, and obtaining a first correction gain of the laser output power according to the ambient temperature.

8. The method for correcting the power of a fiber laser according to claim 1, characterized in that: The method also includes the steps of: obtaining the ambient humidity, and obtaining a second correction gain of the laser output power according to the ambient humidity.

9. The method for correcting the power of a fiber laser according to claim 1, characterized in that: The method further includes the steps of: obtaining the ambient air pressure, and obtaining a third correction gain of the laser output power according to the ambient air pressure.

10. The method for correcting the power of a fiber laser according to claim 1, characterized in that: The method also includes the steps of: obtaining the ambient temperature, humidity and air pressure, and obtaining a fourth correction gain of the laser output power according to the ambient temperature, humidity and air pressure.

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