System and method for automatically optimizing power of frequency-doubled laser

Abstract

The invention provides a system and a method for automatically optimizing the power of a frequency doubling laser, and relates to the technical field of laser. The high-temperature frequency doubling furnace comprises an LBO crystal and a heating sheet, the LBO crystal is used for carrying out high-temperature frequency doubling on laser emitted by the infrared laser, and the heating sheet is used for heating the LBO crystal; the dichroic mirror is used for transmitting the frequency-doubled laser and reflecting and filtering the non-frequency-doubled laser; the spectroscope is used for dividing the frequency-doubled laser into reflected light and transmitted light; the power meter is used for measuring the power of the reflected light; and the temperature controller is used for controlling the heating plate to heat the LBO crystal according to the reflected light power fed back by the power meter so as to adjust the temperature of the LBO crystal and enable the power of the reflected light to fluctuate within a preset range. According to the method, the frequency doubling power of the laser subjected to high-temperature frequency doubling through the LBO crystal can be kept stable and is not influenced by environment temperature fluctuation.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a system and method for automatically optimizing the power of a frequency-doubling laser. Background Art

[0002] LBO crystal high-temperature frequency doubling technology is an important means to improve the frequency doubling power of lasers. However, LBO crystals are extremely sensitive to angle during the high-temperature frequency doubling process. Even a small angle deviation will cause serious phase mismatch. Therefore, the frequency doubling power will drop sharply due to deformation caused by ambient temperature fluctuations. Summary of the Invention

[0003] The present invention aims to provide a system and method for automatically optimizing the power of a frequency-doubled laser, aiming to ensure that the power of a laser frequency-doubled by a high-temperature LBO crystal is not affected by ambient temperature fluctuations. The specific technical solution is as follows:

[0004] A frequency-doubling laser power automatic optimization system, comprising:

[0005] infrared lasers;

[0006] High-temperature frequency doubling furnace, including LBO crystal and heating plate. LBO crystal is used for high-temperature frequency doubling of the infrared laser output laser, and the heating plate is used for heating the LBO crystal.

[0007] A dichroic mirror, used to transmit the frequency-doubled laser light and reflect the non-frequency-doubled light to be filtered;

[0008] A beam splitter, used to split the frequency-doubled laser into reflected light and transmitted light;

[0009] A power meter, used to measure the power of reflected light;

[0010] The temperature controller is used to control the heating of the LBO crystal by the heating plate according to the reflected light power fed back by the power meter, so as to adjust the temperature of the LBO crystal so that the power of the reflected light fluctuates within a preset range.

[0011] Furthermore, the infrared laser is a medium-power infrared laser with a power range of 50W to 100W and a frequency range of 100KHz to 1000KHz.

[0012] Furthermore, the LBO crystal is a high-temperature doubled frequency crystal with a doubled frequency temperature of 140°C to 150°C; the heating plate is a constant temperature ceramic PTC heating plate with a temperature resistance of 300°C.

[0013] Furthermore, the high-temperature frequency doubling furnace further includes a base and a thermistor. The LBO crystal is arranged on the base. The thermistor is used to measure the temperature of the LBO crystal and feed back the temperature to the temperature controller.

[0014] Furthermore, the thermistor is PT1000.

[0015] Furthermore, the dichroic mirror is a 45° dichroic mirror that fully reflects infrared light at 45° and fully transmits green light at 45°.

[0016] Furthermore, the beam splitter is a green light 45° beam splitter with a reflectivity of 1%-5%.

[0017] Furthermore, the temperature controller has a temperature control accuracy of 0.01°C and is equipped with a heater connection interface, a thermistor temperature sensor input interface, and a power meter power monitoring input interface, which can simultaneously monitor the frequency doubling temperature and frequency doubling power of the LBO crystal.

[0018] The present invention also provides a method for automatically optimizing the power of a frequency-doubling laser, which is implemented based on the above-mentioned automatic optimization system for frequency-doubling laser power and includes the following steps: setting an initial frequency-doubling temperature and an initial frequency-doubling power, and controlling a temperature controller to heat an LBO crystal according to the initial frequency-doubling temperature; the temperature controller receives reflected light power fed back by a power meter and compares it with the initial frequency-doubling power; if the reflected light power is within a preset fluctuation range of the initial frequency-doubling power, the temperature controller continues to control the heating plate to heat the LBO crystal at the current initial frequency-doubling temperature; if the reflected light power exceeds the preset fluctuation range of the initial frequency-doubling power, determining an adjusted frequency-doubling temperature, and controlling the heating plate to heat the LBO crystal according to the adjusted frequency-doubling temperature until the reflected light power returns to within the preset fluctuation range of the initial frequency-doubling power, and the temperature controller continues to control the heating plate to heat the LBO crystal at the current adjusted frequency-doubling temperature.

[0019] Furthermore, if the reflected light power exceeds the preset fluctuation range of the initial frequency doubling power, the temperature controller adjusts the temperature upwards in step temperatures based on the initial frequency doubling temperature. If the gap between the reflected light power and the initial frequency doubling power decreases with the increase in temperature and falls within the preset range, the current temperature is locked as the adjusted frequency doubling temperature. If the gap between the reflected light power and the initial frequency doubling power increases with the increase in temperature, the temperature controller starts to adjust the temperature in the opposite direction in step temperatures until the gap between the reflected light power and the initial frequency doubling power decreases with the increase in temperature and falls within the preset range, and the current temperature is locked as the adjusted frequency doubling temperature.

[0020] The present invention provides a system and method for automatically optimizing the power of a frequency-doubled laser, which has the following beneficial effects:

[0021] The present invention provides a power meter for measuring the power of reflected light, and a temperature controller for controlling the heating of the LBO crystal by the heating plate according to the reflected light power fed back by the power meter, so as to adjust the temperature of the LBO crystal so that the power of the reflected light fluctuates within a preset range. Therefore, when the ambient temperature of the LBO crystal in the high-temperature frequency doubling furnace changes, the intensity of the heating of the LBO crystal by the heating plate can be adjusted to keep the frequency doubling temperature of the LBO crystal constant, and the LBO crystal will not be deformed. This ensures that the frequency doubling power of the laser produced by high-temperature frequency doubling of the LBO crystal remains stable and is not affected by ambient temperature fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a frequency-doubling laser power automatic optimization system provided by the present invention;

[0023] Figure 2 The present invention provides a flow chart of a method for automatically optimizing the power of a frequency-doubling laser. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings provided by the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are all in a very simplified form and are not in exact proportions. They are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0025] Example 1

[0026] This embodiment provides a frequency-doubled laser power automatic optimization system, see Figure 1 Shown, including:

[0027] infrared lasers;

[0028] High-temperature frequency doubling furnace, including LBO crystal and heating plate. LBO crystal is used for high-temperature frequency doubling of the infrared laser output laser, and the heating plate is used for heating the LBO crystal.

[0029] A dichroic mirror, used to transmit the frequency-doubled laser light and reflect the non-frequency-doubled light to be filtered;

[0030] A beam splitter, used to split the frequency-doubled laser into reflected light and transmitted light;

[0031] A power meter, used to measure the power of reflected light;

[0032] The temperature controller is used to control the heating of the LBO crystal by the heating plate according to the reflected light power fed back by the power meter, so as to adjust the temperature of the LBO crystal so that the power of the reflected light fluctuates within a preset range.

[0033] In an optional embodiment, the infrared laser is a medium-power infrared laser with a power range of 50W to 100W and a frequency range of 100KHz to 1000KHz.

[0034] In an optional embodiment, the high-temperature frequency doubling furnace further includes a base and a thermistor. The LBO crystal is disposed on the base, and the thermistor is used to measure the temperature of the LBO crystal and feed back the temperature to the temperature controller.

[0035] In one embodiment, the LBO crystal is a high-temperature doubled frequency crystal with a doubled frequency temperature of 140° C. to 150° C.; the thermistor is PT1000; and the heating plate is a constant temperature ceramic PTC heating plate with a temperature resistance of 300° C.

[0036] In an optional embodiment, the dichroic mirror is a 45° dichroic mirror that fully reflects infrared light at 45° and fully transmits green light at 45°.

[0037] In an optional embodiment, the beam splitter is a green light 45° beam splitter with a reflectivity of 1%-5%.

[0038] In an optional embodiment, the temperature controller has a temperature control accuracy of 0.01°C and is provided with a heater connection interface, a thermistor temperature sensor input interface, and a power meter power monitoring input interface, which can simultaneously monitor the frequency doubling temperature and frequency doubling power of the LBO crystal.

[0039] The automatic power optimization system for a frequency-doubling laser provided by the present invention comprises a power meter for measuring the power of reflected light, and a temperature controller for controlling the heating of an LBO crystal by a heating plate based on the reflected light power fed back by the power meter, thereby adjusting the temperature of the LBO crystal so that the power of the reflected light fluctuates within a preset range. Therefore, when the ambient temperature of the LBO crystal in a high-temperature frequency-doubling furnace changes, the intensity of the heating of the LBO crystal by the heating plate can be adjusted to maintain a constant frequency-doubling temperature of the LBO crystal, preventing deformation of the LBO crystal. This ensures that the frequency-doubling power of the laser, which is frequency-doubled by the high-temperature LBO crystal, remains stable and is not affected by ambient temperature fluctuations.

[0040] Example 2

[0041] This embodiment provides a method for automatically optimizing the power of a frequency-doubled laser, which is implemented based on the above-mentioned automatic optimization system for the power of a frequency-doubled laser. Figure 2As shown, the method includes the following steps: setting an initial frequency doubling temperature and an initial frequency doubling power, and controlling the heating plate to heat the LBO crystal according to the initial frequency doubling temperature by a temperature controller; receiving the reflected light power fed back by the power meter and comparing it with the initial frequency doubling power; if the reflected light power is within a preset fluctuation range of the initial frequency doubling power, the temperature controller continues to control the heating plate to heat the LBO crystal at the current initial frequency doubling temperature; if the reflected light power exceeds the preset fluctuation range of the initial frequency doubling power, determining an adjusted frequency doubling temperature, and controlling the heating plate to heat the LBO crystal according to the adjusted frequency doubling temperature until the reflected light power returns to within the preset fluctuation range of the initial frequency doubling power, and the temperature controller continues to control the heating plate to heat the LBO crystal at the current adjusted frequency doubling temperature.

[0042] In a preferred embodiment, if the reflected light power exceeds the preset fluctuation range of the initial frequency doubling power, the temperature controller adjusts the temperature upward in steps based on the initial frequency doubling temperature, for example, the step temperature is 0.01°C. If the reflected light power increases with the temperature and the gap between the initial frequency doubling power is reduced to within the preset range, the current temperature is locked as the adjusted frequency doubling temperature; if the reflected light power increases with the temperature and the gap between the initial frequency doubling power is widened, the temperature controller starts to adjust the temperature in the opposite direction in steps, for example, the step temperature is 0.01°C, until the reflected light power increases with the temperature and the gap between the initial frequency doubling power is reduced to within the preset range, the current temperature is locked as the adjusted frequency doubling temperature.

[0043] In one exemplary embodiment, the infrared laser output power is 100W, the spectrometer reflectivity is 1%, the thermostat heats the frequency-doubling crystal via a constant-temperature ceramic PTC heater, and the temperature of the frequency-doubling crystal is monitored in real time via a PT1000. The high-temperature frequency-doubling crystal is temperature-controlled to an initial optimal frequency-doubling temperature of 147.00°C. At this point, the 100W infrared laser, after frequency-doubling by the frequency-doubling crystal, outputs 75W of frequency-doubled light. The remaining infrared light not converted to frequency-doubled light is reflected by the dichroic mirror and ultimately absorbed by the absorption tube. The 75W of frequency-doubled light is reflected by the spectrometer onto a power meter, which transmits the power to the thermostat. The thermostat then sets the power measured by the power meter to an initial power of 1.5W, and also sets an allowable power fluctuation range of 1.5W±20mW. The thermostat compares and calculates the power signal received in real time with the set initial power value, then generates a temperature control signal based on the deviation value, and converts the control signal output by the thermostat into an electrical signal suitable for driving the constant temperature ceramic PTC heater. The temperature of the frequency doubling crystal is adjusted in real time according to the temperature feedback of the PT1000 to ensure automatic compensation of the frequency doubling power. When the frequency doubling power deviates from the set value, the thermostat initially adjusts the temperature upward based on the initial frequency doubling temperature, in steps of 0.01°C. If the frequency doubling power increases with temperature and the gap between the initial power and the current temperature is narrowed to within the allowable range, the current temperature is locked. After that, the frequency doubling crystal will operate at the currently locked temperature. If the frequency doubling power increases with temperature and the gap between the initial power and the current temperature is widened, the thermostat begins to adjust the temperature in the opposite direction, in steps of 0.01°C, until the gap between the frequency doubling power and the initial power is narrowed to within the allowable range and the current power is locked.

[0044] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention in accordance with the above disclosure are within the scope of protection of the claims.

Claims

1. A frequency-doubled laser power automatic optimization system, characterized in that: include: infrared lasers; High-temperature frequency doubling furnace, including LBO crystal and heating plate. LBO crystal is used for high-temperature frequency doubling of the infrared laser output laser, and the heating plate is used for heating the LBO crystal. A dichroic mirror, used to transmit the frequency-doubled laser light and reflect the non-frequency-doubled light to be filtered; A beam splitter, used to split the frequency-doubled laser into reflected light and transmitted light; A power meter, used to measure the power of reflected light; The temperature controller is used to control the heating of the LBO crystal by the heating plate according to the reflected light power fed back by the power meter, so as to adjust the temperature of the LBO crystal so that the power of the reflected light fluctuates within a preset range.

2. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The infrared laser is a medium-power infrared laser with a power range of 50W to 100W and a frequency range of 100KHz to 1000KHz.

3. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The LBO crystal is a high-temperature doubled frequency crystal with a doubled frequency temperature of 140°C to 150°C; the heating plate is a constant temperature ceramic PTC heating plate with a temperature resistance of 300°C.

4. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The high-temperature frequency doubling furnace also includes a base and a thermistor. The LBO crystal is set on the base, and the thermistor is used to measure the temperature of the LBO crystal and feed it back to the temperature controller.

5. The frequency-doubling laser power automatic optimization system according to claim 4, characterized in that: The thermistor is PT1000.

6. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The dichroic mirror is a 45° dichroic mirror that fully reflects infrared light at 45° and fully transmits green light at 45°.

7. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The spectrometer is a green light 45° spectrometer with a reflectivity of 1%-5%.

8. The frequency-doubling laser power automatic optimization system according to claim 1, characterized in that: The temperature controller has a temperature control accuracy of 0.01°C and is equipped with a heater connection interface, a thermistor temperature sensor input interface, and a power meter power monitoring input interface. It can simultaneously monitor the frequency doubling temperature and frequency doubling power of the LBO crystal.

9. A method for automatically optimizing the power of a frequency-doubled laser, implemented based on the automatic power optimization system for a frequency-doubled laser according to any one of claims 1 to 8, comprising the following steps: The initial frequency doubling temperature and initial frequency doubling power are set, and the temperature controller controls the heating plate to heat the LBO crystal according to the initial frequency doubling temperature; the temperature controller receives the reflected light power fed back by the power meter and compares it with the initial frequency doubling power. If the reflected light power is within the preset fluctuation range of the initial frequency doubling power, the temperature controller continues to control the heating plate to heat the LBO crystal at the current initial frequency doubling temperature; if the reflected light power exceeds the preset fluctuation range of the initial frequency doubling power, the frequency doubling temperature is determined to be adjusted, and the temperature controller controls the heating plate to heat the LBO crystal according to the adjusted frequency doubling temperature until the reflected light power returns to the preset fluctuation range of the initial frequency doubling power, and the temperature controller continues to control the heating plate to heat the LBO crystal at the current adjusted frequency doubling temperature.

10. The method for automatic optimization of frequency-doubled laser power according to claim 9, characterized in that: If the reflected light power exceeds the preset fluctuation range of the initial frequency doubling power, the thermostat adjusts the temperature upwards in steps based on the initial frequency doubling temperature. If the difference between the reflected light power and the initial frequency doubling power decreases with the increase in temperature and falls within the preset range, the current temperature is locked as the adjusted frequency doubling temperature. If the difference between the reflected light power and the initial frequency doubling power increases with the increase in temperature, the thermostat starts to adjust the temperature in the opposite direction in steps until the difference between the reflected light power and the initial frequency doubling power decreases with the increase in temperature and falls within the preset range, at which point the current temperature is locked as the adjusted frequency doubling temperature.

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