Automatic power calibration method and laser equipment for ultraviolet picosecond lasers
By automatically calibrating the laser power in the ultraviolet picosecond laser, the problem of power instability caused by device aging is solved, and the laser can be started up and used efficiently and stably.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-15
- Publication Date
- 2026-04-03
AI Technical Summary
When a picosecond ultraviolet laser is restarted due to improper transportation, abnormal power outage, or changes in ambient temperature, the laser power may be unstable or inconsistent with the target power, requiring multiple adjustments without achieving the target power and affecting its efficiency.
An automatic laser power correction method for ultraviolet picosecond lasers is adopted. By collecting the difference between the initial power and the target power, the temperature of the frequency doubling crystal is adjusted to regulate the initial power until the difference is within the allowable range. Then, the target power value is replaced to ensure that the laser starts up normally.
It enables timely adjustment of power attenuation caused by device aging, avoids the laser getting stuck in the power adjustment process, and ensures smooth laser calibration and high stability.
Smart Images
Figure CN116544769B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of laser processing technology, and in particular to an automatic laser power correction method and laser equipment for an ultraviolet picosecond laser. Background Technology
[0002] Ultraviolet picosecond lasers, with their excellent characteristics, are widely used in communications, industrial manufacturing, precision measurement, gravitational wave detection, and scientific research. In recent years, the power stability of ultraviolet picosecond lasers has received considerable attention. When improper transportation, abnormal power outages, or changes in ambient temperature occur, restarting an ultraviolet picosecond laser may result in unstable laser power or a discrepancy between the laser power and the target power, necessitating readjustment and negatively impacting production efficiency.
[0003] In related technologies, the power of an ultraviolet picosecond laser can be readjusted to the target power either programmatically or manually. However, due to device aging, the power of the laser emitted by an ultraviolet picosecond laser slowly decreases. In this case, if conventional laser power correction methods are used, the laser power may not be able to be adjusted to the target power even after multiple adjustments. In such cases, the ultraviolet picosecond laser will not be ready, and its use will be affected. Summary of the Invention
[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an automatic laser power correction method for ultraviolet picosecond lasers, which can successfully complete laser power correction for ultraviolet picosecond lasers with power attenuation.
[0005] This application also proposes a laser device for implementing the above-described automatic laser power correction method for ultraviolet picosecond lasers.
[0006] The automatic laser power correction method for an ultraviolet picosecond laser according to the first aspect of this application includes the following steps:
[0007] Power on the ultraviolet picosecond laser;
[0008] The initial power P1 of the target laser emitted by the ultraviolet picosecond laser is collected;
[0009] Let the target power be P2 and the target difference be P3. Compare the initial power P1 with the target power P2. If |P1-P2|≤P3, the ultraviolet picosecond laser is ready to start. If |P1-P2|>P3, adjust the initial power P1 until |P1-P2|≤P3, and replace the target power P2 with the value of the adjusted initial power P1.
[0010] The automatic laser power correction method for ultraviolet picosecond lasers according to the embodiments of this application has at least the following beneficial effects: When |P1-P2|>P3, the ultraviolet picosecond laser may have experienced power attenuation due to device aging. By replacing the target power P2 with the value of the adjusted initial power P1, the value of the target power P2 can be adjusted in a timely manner, avoiding the problem that the power attenuation caused by device aging is too large, and the initial power P1 cannot reach the target power P2 no matter how it is adjusted. That is, by timely and appropriately reducing the target power P2, the ultraviolet picosecond laser can be prevented from getting stuck in the power adjustment process, thereby successfully completing the laser power correction for ultraviolet picosecond lasers with power attenuation.
[0011] According to some embodiments of this application, the target difference P3 and the target power P2 satisfy the relationship: P3≤P2×0.01.
[0012] According to some embodiments of this application, the initial power P1 is the average power of the target laser emitted by the ultraviolet picosecond laser within a set time period T1.
[0013] According to some embodiments of this application, the time period T1 is set to 30 to 90 seconds.
[0014] According to some embodiments of this application, if |P1-P2|>P3, the initial power P1 is adjusted through the following steps:
[0015] The initial laser emitted by the ultraviolet picosecond laser is passed through a frequency doubling crystal, which is used to split the initial laser into the target laser and the split laser.
[0016] Adjusting the temperature of the frequency doubling crystal thereby adjusts the initial power P1 of the target laser.
[0017] According to some embodiments of this application, when adjusting the temperature of the frequency doubling crystal, the frequency doubling crystal is placed at multiple temperatures, and the initial power P1 corresponding to the target laser is recorded; under the condition that |P1-P2|≤P3, the temperature of the frequency doubling crystal corresponding to the maximum initial power P1 is taken as the final temperature of the frequency doubling crystal.
[0018] According to some embodiments of this application, when adjusting the temperature of the frequency doubling crystal, the multiple temperatures of the frequency doubling crystal form an arithmetic sequence.
[0019] According to some embodiments of this application, when adjusting the temperature of the frequency doubling crystal, the tolerance of multiple temperatures of the frequency doubling crystal is 0.1°C.
[0020] According to a second aspect embodiment of this application, a laser device is used to implement the above-described automatic laser power correction method for an ultraviolet picosecond laser, comprising:
[0021] Ultraviolet picosecond lasers are used to emit laser light to the target.
[0022] An optical power meter is used to detect the initial power P1 of the target laser. The optical power meter is also used to emit a power signal.
[0023] The controller is used to receive power signals, store the target power P2 and the target difference P3, and compare the magnitude relationship between |P1-P2| and P3. When |P1-P2|≤P3, the controller is used to issue a ready signal; when |P1-P2|>P3, the controller is used to issue a control signal to adjust the magnitude of the initial power P1.
[0024] The laser device according to the embodiments of this application has at least the following beneficial effects: by using the above-described automatic laser power correction method for ultraviolet picosecond lasers, laser power correction can be successfully completed for ultraviolet picosecond lasers with power attenuation, thereby ensuring that the ultraviolet picosecond laser can be used normally.
[0025] According to some embodiments of this application, the ultraviolet picosecond laser is used to emit an initial laser beam and further includes:
[0026] A frequency doubling crystal, located in the optical path of the initial laser, is used to split the initial laser into the target laser and the split laser.
[0027] Temperature control device for adjusting the temperature of the frequency doubling crystal;
[0028] A beam splitter, located in the optical path of the initial laser, is used to separate the target laser from the mixed beam of the target laser and the split laser.
[0029] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0030] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:
[0031] Figure 1 A flowchart illustrating an automatic laser power correction method for an ultraviolet picosecond laser according to an embodiment of this application;
[0032] Figure 2 This is a schematic diagram of a laser device according to the first embodiment of this application;
[0033] Figure 3 This is a schematic diagram of a laser device according to the second embodiment of this application;
[0034] Figure 4 for Figure 3 The startup flowchart of the laser equipment.
[0035] Figure labeling: Ultraviolet picosecond laser 100, initial laser 110, split laser 120, target laser 130;
[0036] Frequency doubling crystal 200;
[0037] 300mm beam splitter;
[0038] Light-absorbing component 400;
[0039] Optical shutter 500;
[0040] Optical power meter 600;
[0041] Temperature control device 700;
[0042] Controller 800. Detailed Implementation
[0043] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0044] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0045] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0046] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0047] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0048] The automatic laser power correction method for ultraviolet picosecond lasers in this application is particularly suitable for high-power (not less than 55W) ultraviolet picosecond lasers. After using the automatic laser power correction method in this application, the laser output power of high-power (not less than 55W) ultraviolet picosecond lasers has high stability.
[0049] Furthermore, although the automatic laser power correction method for ultraviolet picosecond lasers in the embodiments of this application is emphasized to be more suitable for ultraviolet picosecond lasers, it can also be applied to other types and other powers of lasers, such as ultraviolet femtosecond lasers, infrared picosecond lasers, 50W ultraviolet picosecond lasers, etc.
[0050] Reference Figure 1 and Figure 2 The automatic laser power correction method for an ultraviolet picosecond laser according to the first aspect of this application includes the following steps: S100, the ultraviolet picosecond laser 100 is powered on; S200, the initial power P1 of the target laser 130 emitted by the ultraviolet picosecond laser 100 is collected; S300, the target power is set to P2, the target difference is set to P3, and the initial power P1 is compared with the target power P2; if |P1-P2|≤P3, the ultraviolet picosecond laser 100 is ready to start; if |P1-P2|>P3, the initial power P1 is adjusted until |P1-P2|≤P3, and the value of the target power P2 is replaced with the value of the adjusted initial power P1.
[0051] The automatic laser power correction method for ultraviolet picosecond lasers according to the embodiments of this application has at least the following beneficial effects: When |P1-P2|>P3, the ultraviolet picosecond laser 100 may have experienced power attenuation due to device aging. By replacing the value of the target power P2 with the value of the adjusted initial power P1, the value of the target power P2 can be adjusted in a timely manner, avoiding the problem that the power attenuation caused by device aging is too large, and the initial power P1 cannot reach the target power P2 no matter how it is adjusted. That is, by timely and appropriately reducing the target power P2, the ultraviolet picosecond laser 100 can be prevented from getting stuck in the power adjustment process, thereby successfully completing the laser power correction for the ultraviolet picosecond laser 100 with power attenuation.
[0052] In some embodiments of this application, the target difference P3 and the target power P2 satisfy the relationship: P3≤P2×0.01.
[0053] At this point, the absolute value of the difference between the initial power P1 and the target power P2 is no greater than one percent of the target power P2. That is, the initial power P1 is already quite close to the target power P2. The fluctuation range of the initial power P1 of the target laser 130 is relatively small, which is conducive to making the initial power P1 of the target laser 130 more stable.
[0054] Specifically, the target difference P3 can be one percent, eight per thousand, five per thousand, or other values of the target power P2.
[0055] In some embodiments of this application, the initial power P1 is the average power of the target laser 130 emitted by the ultraviolet picosecond laser 100 within a set time period T1.
[0056] By taking the average power of the target laser 130 within a set time period T1, the power of the target laser 130 can be reflected more accurately, which is beneficial for precisely adjusting the initial power P1 of the target laser 130.
[0057] In the improved scheme of the above embodiment, the time period T1 is set to 30 to 90 seconds. The time range of 30 to 90 seconds can ensure that there are enough power values and also take into account the start-up time of the ultraviolet picosecond laser 100, so that the start-up time of the ultraviolet picosecond laser 100 is not too long.
[0058] Specifically, the time period T1 can be 30 seconds, 60 seconds, 90 seconds, or other values.
[0059] Appropriate reference Figure 3 In some embodiments of this application, if |P1-P2|>P3, the initial power P1 is adjusted by the following steps: the initial laser 110 emitted by the ultraviolet picosecond laser 100 is passed through the frequency doubling crystal 200, which is used to split the initial laser 110 into the target laser 130 and the split laser 120; the temperature of the frequency doubling crystal 200 is adjusted, thereby adjusting the initial power P1 of the target laser 130.
[0060] A single-wavelength incident laser beam, after passing through a frequency doubling crystal 200, is converted into a mixed light with multiple wavelengths. A beam splitter 300 can then filter out the target laser 130 from this mixed light. For example, a 1064nm laser beam, after passing through a lithium triborate crystal, can be converted into a mixed light with wavelengths of 355nm, 532nm, and 1064nm, with the 355nm wavelength potentially being the target laser 130.
[0061] Furthermore, the frequency doubling efficiency of the frequency doubling crystal 200 is related to the temperature of the frequency doubling crystal 200. The frequency doubling efficiency is the quotient of the power (or energy) of the laser with a frequency of 2V (or a wavelength of 0.5λ) after passing through the frequency doubling crystal 200 and the power (or energy) of the incident laser with a frequency of V (or a wavelength of λ). By changing the temperature of the frequency doubling crystal 200, the efficiency of the frequency doubling crystal 200 can be changed, thereby adjusting the initial power P1 of the target laser 130.
[0062] That is, by adjusting the temperature of the frequency doubling crystal 200, the initial power P1 of the target laser 130 can be easily adjusted.
[0063] In the improved scheme of the above embodiment, when adjusting the temperature of the frequency doubling crystal 200, the frequency doubling crystal 200 is placed at multiple temperatures, and the initial power P1 corresponding to the target laser 130 is recorded; under the condition that |P1-P2|≤P3, the temperature of the frequency doubling crystal 200 corresponding to the largest initial power P1 is taken as the final temperature of the frequency doubling crystal 200.
[0064] By taking the temperature of the frequency doubling crystal 200 corresponding to the maximum initial power P1 as the final temperature of the frequency doubling crystal 200, the initial power P1 of the target laser can be maximized within the selectable range, which helps to mitigate the adverse effects of power attenuation of the ultraviolet picosecond laser 100.
[0065] In the improved embodiment described above, when adjusting the temperature of the frequency doubling crystal 200, the multiple temperatures of the frequency doubling crystal 200 form an arithmetic sequence.
[0066] Using an arithmetic sequence as the temperature adjustment target for the frequency doubling crystal 200, the temperature of the frequency doubling crystal 200 corresponding to the maximum initial power P1 can be tested systematically, which helps to increase the probability of testing the temperature of the frequency doubling crystal 200 corresponding to the maximum initial power P1.
[0067] In the improved embodiment described above, when adjusting the temperature of the frequency doubling crystal 200, the tolerance of the multiple temperatures at which the frequency doubling crystal 200 is located is 0.1°C.
[0068] The 0.1℃ temperature interval is relatively small, which helps to further increase the probability of testing the temperature of the frequency doubling crystal 200 corresponding to the maximum initial power P1.
[0069] In another embodiment, when adjusting the temperature of the frequency doubling crystal 200, the tolerance of the multiple temperatures at which the frequency doubling crystal 200 is located can also be 0.15°C, 0.2°C, 0.25°C or other values.
[0070] Reference Figure 2According to a second aspect embodiment of this application, a laser device for implementing the above-described automatic laser power correction method for an ultraviolet picosecond laser includes an ultraviolet picosecond laser 100, an optical power meter 600, and a controller 800. The ultraviolet picosecond laser 100 emits a target laser 130. The optical power meter 600 detects the initial power P1 of the target laser 130 and also emits a power signal. The controller 800 receives the power signal, stores a target power of P2 and a target difference of P3, and compares the magnitudes of |P1-P2| and P3. When |P1-P2| ≤ P3, the controller 800 emits a ready signal; when |P1-P2| > P3, the controller 800 emits a control signal to adjust the magnitude of the initial power P1.
[0071] The laser device according to the embodiments of this application has at least the following beneficial effects: by using the above-described automatic laser power correction method for ultraviolet picosecond lasers, laser power correction can be successfully completed for ultraviolet picosecond lasers 100 that have power attenuation, thereby ensuring that the ultraviolet picosecond laser 100 can be used normally.
[0072] Specifically, to adjust the initial power P1, the controller 800 sends a control signal to control the current of the pump source of the ultraviolet picosecond laser 100, thereby adjusting the initial power P1. In addition, the controller 800 can also send a control signal to control the temperature of the frequency doubling crystal 200 (details of the adjustment method are described below), thereby adjusting the initial power P1.
[0073] Specifically, the controller 800 includes a memory and an arithmetic circuit. The memory can store the initial power P1, the target power P2, and the target difference P3. The arithmetic circuit can calculate the relationship between |P1-P2| and P3.
[0074] Specifically, the laser device also includes a light-absorbing component 400 and an optical shutter 500. The optical shutter 500 is used to control whether the target laser 130 is emitted or not, and the light-absorbing component 400 is used to absorb the non-emitting target laser 130. Both the light-absorbing component 400 and the optical shutter 500 are existing technologies, and their structures will not be described again here.
[0075] In the improved embodiment described above, the ultraviolet picosecond laser 100 is used to emit an initial laser 110. The laser device also includes a frequency doubling crystal 200, a beam splitter 300, and a temperature control device 700. The frequency doubling crystal 200 is located in the optical path of the initial laser 110 and is used to split the initial laser 110 into a target laser 130 and a split laser 120. The temperature control device 700 is used to adjust the temperature of the frequency doubling crystal 200. The beam splitter 300 is located in the optical path of the initial laser 110 and is used to separate the target laser 130 from the mixed beam of the target laser 130 and the split laser 120.
[0076] Therefore, by adjusting the temperature of the frequency doubling crystal 200 through the temperature adjustment device 700, the initial power P1 of the target laser 130 can be adjusted, and the target laser 130 can be separated from the mixed beam of the target laser 130 and the split laser 120 through the beam splitter 300.
[0077] Specifically, the temperature regulating device 700 may include a semiconductor cooler, which can raise or lower the temperature of the frequency doubling crystal 200. Alternatively, the temperature regulating device 700 may also include a heating element, thereby controlling the temperature of the frequency doubling crystal 200.
[0078] Reference Figure 4 Based on the above, the startup process of the ultraviolet picosecond laser 100 is explained.
[0079] The first step is for the ultraviolet picosecond laser 100 to perform a self-check of temperature and humidity to ensure that the operating environment of the ultraviolet picosecond laser 100 meets the operating requirements.
[0080] The second step is to allow water to flow through the ultraviolet picosecond laser 100 if the temperature and humidity meet the requirements; otherwise, an alarm signal will be sent and the ultraviolet picosecond laser 100 will stop flowing water.
[0081] The third step is a self-test of all system signals (including chiller temperature readiness), which usually takes about 5 minutes.
[0082] Step 4: If the system signal self-test is qualified, the various LDs (laser diodes) and seed source of the ultraviolet picosecond laser 100 are powered on; if the system signal self-test is unqualified, an alarm signal is sent, and the various LDs (laser diodes) and seed source of the ultraviolet picosecond laser 100 are not powered on.
[0083] Step 5: After the various LDs (laser diodes) and seed source of the ultraviolet picosecond laser 100 are powered on, the ultraviolet picosecond laser 100 enters the thermal equilibrium process, which generally lasts for about 10 minutes.
[0084] Step 6: During the thermal equilibrium process, the ultraviolet picosecond laser 100 performs automatic laser power correction. Specifically, the optical power meter 600 collects multiple initial power P1 data of the target laser 130 within one minute, and the controller 800 calculates the average value of the multiple initial powers P1. Then, the controller 800 compares the magnitude relationship between |P1-P2| and P3. When |P1-P2|≤P3, the ultraviolet picosecond laser 100 completes thermal equilibrium; when |P1-P2|>P3, the controller 800 sends a control signal. After receiving the control signal, the temperature regulation device 700 adjusts the magnitude of the initial power P1 by adjusting the frequency doubling crystal 200 until the initial power P1 is adjusted to satisfy the relationship |P1-P2|≤P3. Then, the value of the target power P2 is replaced with the value of the adjusted initial power P1.
[0085] Step 7: Controller 800 sends a ready signal.
[0086] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.
Claims
1. An automatic laser power correction method for an ultraviolet picosecond laser, characterized in that, Includes the following steps: Power on the ultraviolet picosecond laser; The initial power P1 of the target laser emitted by the ultraviolet picosecond laser is collected; Let the target power be P2 and the target difference be P3. Compare the initial power P1 with the target power P2. If |P1-P2|≤P3, the ultraviolet picosecond laser is ready to start. If |P1-P2|>P3, adjust the initial power P1 until |P1-P2|≤P3, and replace the target power P2 with the value of the adjusted initial power P1. Among them, the target difference P3 and the target power P2 satisfy the relationship: P3≤P2×0.
01.
2. The automatic laser power correction method for an ultraviolet picosecond laser according to claim 1, characterized in that, The initial power P1 is the average power of the target laser emitted by the ultraviolet picosecond laser within a set time period T1.
3. The automatic laser power correction method for an ultraviolet picosecond laser according to claim 2, characterized in that, Set the time period T1 to 30-90 seconds.
4. The automatic laser power correction method for an ultraviolet picosecond laser according to any one of claims 1 to 3, characterized in that, If |P1-P2|>P3, adjust the initial power P1 using the following steps: The initial laser emitted by the ultraviolet picosecond laser is passed through a frequency doubling crystal, which is used to split the initial laser into the target laser and the split laser. Adjusting the temperature of the frequency doubling crystal thereby adjusts the initial power P1 of the target laser.
5. The automatic laser power correction method for an ultraviolet picosecond laser according to claim 4, characterized in that, When adjusting the temperature of the frequency doubling crystal, the frequency doubling crystal is placed at multiple temperatures, and the initial power P1 corresponding to the target laser is recorded. Under the condition that |P1-P2|≤P3, the temperature of the frequency doubling crystal corresponding to the maximum initial power P1 is taken as the final temperature of the frequency doubling crystal.
6. The automatic laser power correction method for an ultraviolet picosecond laser according to claim 5, characterized in that, When adjusting the temperature of the frequency doubling crystal, the multiple temperatures of the frequency doubling crystal form an arithmetic sequence.
7. The automatic laser power correction method for an ultraviolet picosecond laser according to claim 6, characterized in that, When adjusting the temperature of the frequency doubling crystal, the tolerance between the multiple temperatures of the frequency doubling crystal is 0.1℃.
8. A laser device, characterized in that, The automatic laser power correction method for implementing the ultraviolet picosecond laser according to any one of claims 1 to 7 includes: Ultraviolet picosecond lasers are used to emit laser light to the target. An optical power meter is used to detect the initial power P1 of the target laser. The optical power meter is also used to emit a power signal. The controller is used to receive power signals, store the target power P2 and the target difference P3, and compare the magnitude relationship between |P1-P2| and P3. When |P1-P2|≤P3, the controller is used to issue a ready signal; when |P1-P2|>P3, the controller is used to issue a control signal to adjust the magnitude of the initial power P1.
9. The laser device according to claim 8, characterized in that, The ultraviolet picosecond laser is used to emit the initial laser beam and also includes: A frequency doubling crystal, located in the optical path of the initial laser, is used to split the initial laser into the target laser and the split laser. Temperature control device for adjusting the temperature of the frequency doubling crystal; A beam splitter, located in the optical path of the initial laser, is used to separate the target laser from the mixed beam of the target laser and the split laser.
Citation Information
Patent Citations
Calibration method of ultraviolet laser and ultraviolet laser
CN116111438A