Lightweight laser power energy tester and test method thereof

Abstract

The invention provides a lightweight laser power energy tester and a test method thereof. The tester comprises a power energy probe, a data acquisition host and a control processing system. The power energy probe comprises a laser energy measurement assembly. The laser energy measurement assembly comprises an energy absorption cavity, a back scattering measurement module, a water cooling module and a temperature difference measurement module. The data acquisition host comprises a water flow and water temperature difference measuring assembly; and the control processing system calculates the measurement result to obtain the measured laser energy. The test method comprises the following steps: recording water inlet and outlet temperature, backscattering monitoring temperature and photoelectric detector output voltage value; determining the minimum value, the maximum value and the temperature rise of the monitoring temperature, and the temperature rise and the laser energy of water; determining the sudden rising / falling time, the light emitting time and the average power of the output voltage of the photoelectric detector; and calculating a waveform area to obtain a power distribution curve. According to the method, the sub-second laser average power is given in the measurement process by adopting a power estimation algorithm.

Description

Technical Field

[0001] The invention belongs to the technical field of optical metrology, and in particular relates to a lightweight laser power energy tester and a testing method thereof. Background Art

[0002] Laser power energy tester is mainly used to measure the output power energy of high-power laser. Laser power energy tester converts laser power energy into heat and calculates laser power energy by measuring the energy temperature difference. In recent years, with the development of technology, the core components of high-power lasers have been maturing, and the output power energy of lasers has been increasing.

[0003] The traditional laser power energy tester with all-solid-state design not only increases in size and weight as the power energy measured increases, but the all-solid-state design is more suitable for providing the laser energy and power measured only after the light emission ends. In addition, the laser power energy tester with all-solid-state design has inaccurate sub-second laser average power measurement at the beginning of the measurement due to the small temperature difference generated by the laser; at the end of the measurement due to the high temperature and severe heat loss, the sub-second laser average power measurement result is also inaccurate. Therefore, the traditional laser power energy tester cannot meet the needs of sub-second laser average power measurement during the laser emission period.

[0004] In recent years, in order to overcome the volume and weight disadvantages of all-solid-state laser power energy testers, liquid-cooled laser power energy testers have been used. Since liquid-cooled laser power energy testers increase the measurable laser energy by increasing the volume of cooling water, their volume and weight no longer increase with the increase of the measured laser power energy. However, this type of liquid-cooled laser power energy tester has a longer temperature stabilization time and cannot achieve sub-second laser average power measurement. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art such as heavy volume and long measurement time, and to provide a lightweight laser power energy tester and a testing method thereof, which utilizes a power estimation algorithm to shorten the response time of the laser power energy tester and provide a sub-second laser average power during the measurement process.

[0006] To achieve the above purpose, the technical solution provided by the present invention is:

[0007] In one aspect, the present invention provides a lightweight laser power energy tester, comprising: a power energy sensor, a data acquisition host and a control processing system; wherein:

[0008] The power energy probe comprises a laser energy measurement component, which comprises: an energy absorption cavity, a backscattering measurement module, a water cooling module and a temperature difference measurement module, wherein the energy absorption cavity is used to absorb most of the energy of the incident laser, the backscattering measurement module is used to measure a small part of the energy of the incident laser, and the measurement result corresponding to the small part of the energy is compensated to the laser energy corresponding to the majority of the energy; the water cooling module cools the energy in the energy absorption cavity, the water passes through the water cooling module and heats up to generate a temperature difference, and the temperature difference measurement module measures the temperature difference;

[0009] The data acquisition host comprises a water flow and water temperature difference measuring component, which collects the water flow of the water cooling module and the water temperature difference of the temperature difference measuring module to obtain a measurement result;

[0010] The control processing system calculates the measurement results of the data acquisition host and the backscattering measurement module to obtain the measured laser energy; the measurement and control results of the water flow and water temperature difference measurement component are combined with the power estimation algorithm to obtain the laser power during the measurement process of the lightweight laser power energy tester.

[0011] Based on one aspect, in a specific implementation of the present invention, the power energy probe further includes: an ambient temperature measurement sensor; the data acquisition host includes: a high-precision resistance acquisition card;

[0012] The ambient temperature measurement sensor and the high-precision resistance acquisition card jointly collect the ambient temperature of the lightweight laser power energy tester;

[0013] The control processing system determines whether the ambient temperature is too high or too low according to the ambient temperature, and introduces an energy compensation factor in the calculation process of measuring the laser energy.

[0014] Based on one aspect, in a specific implementation of the present invention, the power energy probe further includes: an electrical calibration component;

[0015] The electrical calibration component is used to provide accurate measurement of energy and calibrate a lightweight laser power energy tester.

[0016] Based on one aspect, in a specific implementation of the present invention, the power energy probe further includes: a waveform measurement component; the data acquisition host includes: a photoelectric signal amplification circuit and an acquisition card;

[0017] The waveform measurement component is used to measure the laser output power fluctuation signal;

[0018] The photoelectric signal amplification circuit and the acquisition card collect power fluctuation signals;

[0019] The control processing system calculates the laser emission time according to the power fluctuation signal, and obtains the laser average power by combining the measured laser energy.

[0020] Based on one aspect, in a specific implementation of the present invention, the temperature difference measurement module is installed at the water inlet and outlet;

[0021] The water flow in the energy absorption chamber absorbs the energy of the laser power to increase the temperature. The temperature difference measurement module measures the change in water temperature before and after the water flows through the energy absorption chamber to obtain the temperature difference.

[0022] Based on one aspect, in a specific implementation of the present invention, the calculation expression of the laser power P is:

[0023]

[0024] In formula (1), C represents the specific heat capacity of water, ρ represents the water density, Q represents the water flow rate, ΔT represents the temperature difference between the inlet and outlet water of the power meter, and T 出水 Indicates the outlet temperature, T 入水 Indicates the water inlet temperature.

[0025] Based on one aspect, in a specific implementation of the present invention, the power estimation algorithm includes:

[0026] (1) Record the laser power at different times (t1, p1), (t2, p2), ..., (t n ,p n );

[0027] (2) Use formula (2) to calculate the adjacent laser power difference Δp n-1 :

[0028] Δp n-1 =p n -p n-1 Formula (2)

[0029] In formula (2), p n represents the laser power at time n, p n-1 represents the laser power at time n-1, and n represents different times;

[0030] (3) Difference of adjacent laser powers Δp n-1 After reaching the maximum, the difference in adjacent laser powers Δp n-1 The subsequent values ​​are fitted according to formula (3):

[0031]

[0032] In formula (3), a and b represent the coefficients that need to be obtained in the end of data fitting;

[0033] (4) Using formula (4) to calculate the estimated power value p 估 , and the estimated power value p 估 As the average power of the laser in the sub-second level; if the actual measured output power value p corresponding to the test result 测 And the estimated power value p 估 If the difference is within 2%, stop estimating and measure the actual output power value p 测 As the average laser power of the laser at the sub-second level, formula (4) is:

[0034] Based on one aspect, in a specific implementation of the present invention, the control processing system also outputs the laser energy E and the average power P after the measurement is completed. 平均 and the power distribution curve, where:

[0035] The calculation expression of laser energy E is:

[0036] E=Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 Formula (5)

[0037] In formula (5), C represents the specific heat capacity of water, m 水 Indicates the mass of water, ΔT 总 represents the total temperature rise of water, C 监测 Indicates the specific heat capacity of the material used in the backscattering measurement module, m 监测 Indicates the weight of the material used in the backscatter measurement module, ΔT 监测 Represents the temperature rise generated by the backscatter measurement module;

[0038] Average power P 平均 The calculation expression is:

[0039]

[0040] In formula (6), E represents the laser energy, and t represents the laser emission time;

[0041] The calculation expressions of the power distribution curve include:

[0042] The detector photoelectric response v(t) is proportional to the laser input power P(t) and is expressed as:

[0043] v(t)=αP(t) Formula (7)

[0044] In formula (7), α represents the proportional constant;

[0045] Integrating formula (7) yields:

[0046]

[0047] In formula (8), represents the waveform area S, represents the laser energy E;

[0048] The laser time distribution function is expressed as:

[0049]

[0050] The power distribution curve is obtained according to formula (9).

[0051] On the other hand, the present invention further provides a testing method for a lightweight laser power energy tester. Based on the lightweight laser power energy tester of the above aspect, the testing method comprises the following steps:

[0052] Step 1: (11) at equal intervals of time t 间 , record the water inlet temperature T of the water cooling module at different times 入水 and outlet temperature T 出水 , we get (t1,T 入水1 ), (t2,T 入水2 ),……,(t n ,T 入水n );(t1,T 出水1 ), (t2,T 出水2 ),……,(t n ,T 出水n );(12) At equal intervals t 间 , record the backscatter monitoring temperature T of the backscatter measurement module 监测 , we get (t1,T 监测1 ), (t2,T 监测2 ),……,(t n ,T 监测n );(13) At equal intervals t 间 , record the output voltage value V of the photodetector, and obtain (t1, V1), (t2, V2), ..., (t n ,V n );

[0053] Step 2: (21) Determine the minimum backscattering monitoring temperature T before the laser emits light 监测小 , and the minimum value of the average temperature of the water outlet and the water inlet T 水小 ; (22) After the laser emits light, it determines the maximum backscattering monitoring temperature T 监测大 , and the equilibrium value T after the outlet and inlet temperatures are the same 水平 ; (23) Calculate the backscatter monitoring temperature rise ΔT 监测 =T监测大 -T 监测小 , and the temperature rise of water ΔT 总 =T 水平 -T 水小 ; The laser energy E is calculated using formula (5), which is: E = Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 ;

[0054] Step 3: (31) Determine the sudden rise time t of the output voltage of the photodetector 升 , and the sudden drop time of the output voltage t 降 ; (32) Calculate the laser emission time t = t 降 -t 升 ; (33) Use formula (6) to calculate the average power P 平均 , formula (6) is:

[0055] Step 4: (41) Using the output voltages (t1, V1), (t2, V2), ..., (t n ,V n ), calculate the waveform area S, where: (42) The power distribution curve is obtained using formula (9), which is:

[0056] Based on one aspect, in a specific implementation of the present invention, step five is also included: after the measurement is completed, value traceability is performed through electrical calibration; specifically:

[0057] (51) A high-power bulb is used as the calibration source. The high-power bulb is directly placed in the energy absorption cavity, and a high-precision voltmeter is used to monitor the voltage of the two electrodes of the high-power bulb; (52) A high-precision voltmeter and a precision resistor are used to obtain the current of the high-power bulb, and the power of the high-power bulb is monitored in real time. The power is integrated to obtain the final standard energy E 标 , the energy of the lightweight laser power energy tester is recorded as E 测 , calibration factor (53) Based on the calibration coefficients, step three and step four, the final results of laser energy, average power, and power distribution curve are obtained.

[0058] The advantages of the present invention are:

[0059] 1. The present invention utilizes a power estimation algorithm to shorten the response time of a laser power energy tester and provides a sub-second average laser power during the measurement process.

[0060] 2. The present invention ensures the energy generated by the laser can be traced back to the source of the standard energy by adding an electrical calibration component. The voltage, resistance and time can all be traced back to the superior metrology organization to ensure the accuracy of the measurement value.

[0061] 3. The present invention adds a backscatter monitoring module and a power estimation algorithm to improve the measurement uncertainty of laser power energy, shorten the response time of laser power, and reduce the weight of the laser power energy tester when using the same power measurement, thereby improving the ease of use of the laser power energy tester.

[0062] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0064] Figure 1 : A principle block diagram of a lightweight laser power energy tester provided by the present invention;

[0065] Figure 2 : An internal structure diagram of a lightweight laser power energy tester provided by the present invention;

[0066] Figure 3 : A laser energy traceability diagram of a lightweight laser power energy tester provided by the present invention. DETAILED DESCRIPTION

[0067] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0068] See also Figure 1 The embodiment of the present invention discloses a lightweight laser power energy tester, including: (1) a power energy sensor, (2) a data acquisition host and (3) a control processing system; wherein:

[0069] (1) The power energy sensor includes a laser energy measurement component, which includes: an energy absorption chamber, a backscattering measurement module, a water cooling module and a temperature difference measurement module. The energy absorption chamber is used to absorb most of the energy of the incident laser. The backscattering measurement module is used to measure a small part of the energy of the incident laser, and the measurement result corresponding to the small part of the energy is compensated to the laser energy corresponding to the majority of the energy; the water cooling module cools the energy in the energy absorption chamber, and the water passes through the water cooling module to increase the temperature to generate a temperature difference, and the temperature difference measurement module measures the temperature difference. Preferably, the temperature difference measurement module of the embodiment of the present invention is installed at the water inlet and outlet; the water flow in the energy absorption chamber absorbs the energy of the laser power to increase the temperature, and the temperature difference measurement module measures the change in water temperature before and after the water flows through the energy absorption chamber to obtain the temperature difference.

[0070] Preferably, in the laser energy measurement component of the embodiment of the present invention, the energy absorption cavity is mainly used to absorb the incident laser energy, and most of the incident laser is absorbed by the energy absorption cavity, and only a small part is measured by the backscattering measurement module, and the measurement result is compensated to the laser energy absorbed by the energy absorption cavity. The energy absorption cavity of the embodiment of the present invention is cooled by a water cooling module, and the temperature of the water rises after passing through the water cooling module to produce a temperature difference. The water flow and temperature difference flowing through the water cooling module are measured by the water flow and water temperature difference measurement component in the data acquisition host. The measurement result of the backscattering measurement module and the measurement result of the water flow and water temperature difference measurement component are calculated to obtain the measured laser energy. The measurement result of the water flow and water temperature difference measurement component itself is combined with the power estimation algorithm to give the laser power during the measurement process. The signal of the ambient temperature measurement component of the embodiment of the present invention is collected by a high-precision resistor acquisition card to measure the ambient temperature of the lightweight laser power energy tester. If the ambient temperature is too high or too low, an energy compensation factor needs to be introduced when calculating the laser energy.

[0071] Please continue reading Figure 1 In addition to the laser energy measurement component, the above-mentioned power energy probe also includes an ambient temperature measurement sensor; the ambient temperature measurement sensor and the high-precision resistance acquisition card in the (2) data acquisition host jointly collect the ambient temperature of the lightweight laser power energy tester.

[0072] In addition, the above-mentioned power energy probe also includes an electrical calibration component and a waveform measurement component; the electrical calibration component is used to provide accurately measured energy and calibrate the lightweight laser power energy tester. The waveform measurement component is used to measure the laser output power fluctuation signal. Preferably, the waveform measurement component of the embodiment of the present invention is a photoelectric detector with a fast response speed. The photoelectric detector is used to measure the laser output power fluctuation. The measured signal is collected by the photoelectric signal amplification circuit and the acquisition card in the data acquisition host as part of the final processing result. After the photoelectric detector measurement is completed, the relevant data obtained by the waveform measurement component is used to calculate the laser light emission time, and the average power is obtained by combining the measured laser energy. The instantaneous fluctuation of the power is obtained by multiplying the fluctuation change with the calculated coefficient.

[0073] The electrical calibration assembly of the embodiment of the present invention is composed of a power-monitorable light source and its power supply system, which is mainly used to provide energy that can be accurately measured and used to calibrate a lightweight laser power energy meter. Figure 3 The embodiment of the present invention uses laser energy tracing to calibrate power energy at any time.

[0074] (2) The data acquisition host includes a water flow and water temperature difference measurement component, which collects the water flow of the water cooling module and the water temperature difference of the temperature difference measurement module to obtain the measurement results.

[0075] Please continue reading Figure 1 In addition to the water flow and water temperature difference measurement components, the above-mentioned data acquisition host also includes a high-precision resistance acquisition card. (1) The ambient temperature measurement sensor in the power energy probe and the high-precision resistance acquisition card jointly collect the ambient temperature of the lightweight laser power energy tester; (3) The control processing system determines whether the ambient temperature is too high or too low based on the ambient temperature, and introduces an energy compensation factor in the calculation process of measuring laser energy.

[0076] For further information, please refer to Figure 3 The data acquisition host of the embodiment of the present invention also includes a photoelectric signal amplification circuit and an acquisition card; the photoelectric signal amplification circuit and the acquisition card collect power fluctuation signals; (3) the control processing system calculates the laser light emission time according to the power fluctuation signal, and obtains the laser average power by combining the measured laser energy.

[0077] The embodiment of the present invention provides laser energy, average power, and power distribution curve after the measurement is completed; and provides sub-second laser average power during the measurement process. The embodiment of the present invention uses a power estimation method to shorten the response time of the laser power energy meter, and can also perform on-site calibration of the laser power energy meter.

[0078] (3) The control processing system calculates the measurement results of the data acquisition host and the backscattering measurement module to obtain the measured laser energy; the measurement and control results of the water flow and water temperature difference measurement components are combined with the power estimation algorithm to obtain the laser power during the measurement process of the lightweight laser power energy tester. Specifically:

[0079] (31) The calculation expression of the laser power P in the embodiment of the present invention is:

[0080]

[0081] In formula (1), C represents the specific heat capacity of water, ρ represents the water density, Q represents the water flow rate, ΔT represents the temperature difference between the inlet and outlet water of the power meter, and T 出水 Indicates the outlet temperature, T 入水 Indicates the water inlet temperature.

[0082] (32) The power estimation algorithm of the embodiment of the present invention includes:

[0083] (321) Record the laser power at different times (t1, p1), (t2, p2), ..., (t n ,p n );

[0084] (322) Formula (2) is used to calculate the adjacent laser power difference Δp n-1 :

[0085] Δp n-1 =p n -p n-1 Formula (2)

[0086] In formula (2), p n represents the laser power at time n, p n-1 represents the laser power at time n-1, and n represents different times;

[0087] (323) Difference of adjacent laser powers Δp n-1 After reaching the maximum, the difference in adjacent laser powers Δp n-1 The subsequent values ​​are fitted according to formula (3):

[0088]

[0089] In formula (3), a and b represent the coefficients that need to be obtained in the end of data fitting;

[0090] (324) Using formula (4), the estimated power value p is calculated 估 , and the estimated power value p 估 As the average power of the laser in the sub-second level; if the actual measured output power value p corresponding to the test result 测And the estimated power value p 估 If the difference is within 2%, stop estimating and measure the actual output power value p 测 As the average laser power of the laser at the sub-second level, formula (4) is:

[0091] (33) The control processing system of the embodiment of the present invention also outputs the laser energy E and the average power P after the measurement. 平均 and the power distribution curve, where:

[0092] (331) The calculation expression of laser energy E is:

[0093] E=Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 Formula (5)

[0094] In formula (5), C represents the specific heat capacity of water, m 水 Indicates the mass of water, ΔT 总 represents the total temperature rise of water, C 监测 Indicates the specific heat capacity of the material used in the backscattering measurement module, m 监测 Indicates the weight of the material used in the backscatter measurement module, ΔT 监测 Represents the temperature rise generated by the backscatter measurement module;

[0095] (332) Average power P 平均 The calculation expression is:

[0096]

[0097] In formula (6), E represents the laser energy, and t represents the laser emission time;

[0098] (333) The calculation expression of the power distribution curve includes:

[0099] The detector photoelectric response v(t) is proportional to the laser input power P(t) and is expressed as:

[0100] v(t)=αP(t) Formula (7)

[0101] In formula (7), α represents the proportional constant;

[0102] Integrating formula (7) yields:

[0103]

[0104] In formula (8), represents the waveform area S, represents the laser energy E;

[0105] (334) The laser time distribution function is expressed as:

[0106]

[0107] The power distribution curve is obtained according to formula (9).

[0108] The lightweight laser power energy tester of the embodiment of the present invention adopts a water cooling structure. The laser power causes the temperature of the water flowing through the outside of the energy absorption chamber to rise, and the water and the inner surface as the heat absorption surface maintain a temperature close to room temperature, so that radiation and convection are negligible. The water flows through the energy absorption chamber before and after a temperature difference occurs, and temperature sensors are installed at the water inlet and outlet to accurately measure the water temperature change.

[0109] Based on the above-disclosed lightweight laser power energy tester, an embodiment of the present invention also discloses a testing method for a lightweight laser power energy tester. Since the response time of the laser power energy tester using the calorimetric method is relatively long, the time from the laser light emission to the laser power energy tester giving a stable sub-second laser average power reading is generally greater than about 30s. In order to be able to give the measured laser power value before the laser power energy tester reaches stability, the embodiment of the present invention uses the current measurement results combined with the power estimation algorithm to estimate the laser power. The test method uses the power output curve of the power energy tester before the stable output is approximately an exponential curve to perform power evaluation. Specifically:

[0110] The testing method of the embodiment of the present invention comprises the following steps:

[0111] Step 1, (11) at equal intervals of time t 间 , record the water inlet temperature T of the water cooling module at different times 入水 and outlet temperature T 出水 , we get (t1,T 入水1 ), (t2,T 入水2 ),……,(t n ,T 入水n );(t1,T 出水1 ), (t2,T 出水2 ),……,(t n ,T 出水n );(12) At equal intervals t 间 , record the backscatter monitoring temperature T of the backscatter measurement module 监测 , we get (t1,T 监测1 ), (t2,T 监测2 ),……,(t n ,T 监测n );(13) At equal intervals t 间, record the output voltage value V of the photodetector, and obtain (t1, V1), (t2, V2), ..., (t n ,V n );

[0112] Step 2: (21) Determine the minimum backscattering monitoring temperature T before the laser emits light 监测小 , and the minimum value of the average temperature of the water outlet and the water inlet T 水小 ; (22) After the laser emits light, it determines the maximum backscattering monitoring temperature T 监测大 , and the equilibrium value T after the outlet and inlet temperatures are the same 水平 ; (23) Calculate the backscatter monitoring temperature rise ΔT 监测 =T 监测大 -T 监测小 , and the temperature rise of water ΔT 总 =T 水平 -T 水小 ; The laser energy E is calculated using formula (5), which is: E = Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 ;

[0113] Step 3, (31) determine the sudden rise time t of the output voltage of the photodetector 升 , and the sudden drop time of the output voltage t 降 ; (32) Calculate the laser emission time t = t 降 -t 升 ; (33) Use formula (6) to calculate the average power P 平均 , formula (6) is:

[0114] Step 4, (41) using the output voltages (t1, V1), (t2, V2), ..., (t n ,V n ), calculate the waveform area S, where: (42) The power distribution curve is obtained using formula (9), which is:

[0115] Step 5: After the measurement is completed, the value is traced back through electrical calibration; specifically:

[0116] (51) A high-power bulb is used as the calibration source. The high-power bulb is directly placed in the energy absorption cavity, and a high-precision voltmeter is used to monitor the voltage of the two electrodes of the high-power bulb; (52) A high-precision voltmeter and a precision resistor are used to obtain the current of the high-power bulb, and the power of the high-power bulb is monitored in real time. The power is integrated to obtain the final standard energy E标 , the energy of the lightweight laser power energy tester is recorded as E 测 , calibration factor (53) Based on the calibration coefficients, steps 3 and 4, the final results of laser energy, average power, and power distribution curve are obtained.

[0117] More specifically, the above test method is used to trace the value through the electrical calibration component after the test is completed. In ordinary laser power energy calibration, electrical calibration usually adopts the electric heating method. In high-power energy calibration, the system is more complex, and the photoelectric inequivalence coefficient generated by the electric heating method is difficult to accurately obtain. Therefore, the embodiment of the present invention adopts the above high-power bulb as the calibration source. Please continue to refer to Figure 3 In order to ensure that the energy generated can be traced back, a traceability method for standard energy is given. The voltage, resistance and time can all be traced back to the superior measurement agency to ensure the accuracy of the measurement value.

[0118] See also Figure 2 The lightweight laser power energy tester of the embodiment of the present invention includes a water container, a temperature sensor, and a power energy probe (probe). The power energy probe (probe) includes a temperature sensor, a hemispherical reflector, a rear absorption plate, a main absorption tube, and a backscattering measurement module. The water flow in the water container enters the energy absorption cavity through the water inlet, absorbs heat, and collects the water flow temperature through the temperature sensor. The water flow that exchanges heat with the main absorption tube enters the water container from the water outlet. The incident laser is arranged in front of the incident window to provide a measurement laser. The laser is incident on the hemispherical reflector in the main absorption tube and is scattered by the hemispherical reflector to the inner wall of the absorption cavity. Most of the light reflected on the inner wall of the absorption cavity is absorbed, and only a small part of the light is secondary scattered. Part of the secondary scattered light escapes from the laser incident port in front of the absorption cavity, and the power of this part of the escaped light is proportionally compensated to the laser energy absorbed by the energy absorption cavity using the measurement result of the backscattering measurement module.

[0119] Please continue reading Figure 2 , taking a high power laser (preferably a 10,000 watt laser) as an example, combined with Figure 2 The present invention discloses an application example of the test method of the embodiment of the present invention. The test method of this application example includes the following steps:

[0120] (1) Adjust the incident direction of the high-power laser so that the laser can be incident on the power energy sensor.

[0121] (2) Turn on the water circulation system of the corresponding water container and turn on the main unit of the lightweight laser power energy tester for preheating.

[0122] (3) At equal intervals t 间 , record the inlet and outlet temperatures T at different times 入水 , T出水 And backscatter monitoring temperature T 监测 , (t1, T 入水1 ), (t2, T 入水2 ),…(t n , T 入水n );(t1,T 出水1 ), (t2, T 出水2 ),…(t n , T 出水n );(t1,T 监测1 ), (t2, T 监测2 ),…(t n , T 监测n ). At equal intervals of time t 间 , record the output voltage values ​​of the photodetector (t1, V1), (t2, V2), … (t n , V3). Find the minimum backscatter monitoring temperature T 监测小 , and the minimum value of the average temperature of the outlet and inlet T 水小 .

[0123] (4) Turn on the high-power laser to emit laser light.

[0124] (5) Calculate the laser power P according to formula (1) and record the laser powers at different times (t1, p1), (t2, p2), ..., (t n ,p n ).

[0125] (6) Use formula (2) to calculate the adjacent laser power difference Δp n-1 .

[0126] (7) When the adjacent laser power difference Δp n-1 After reaching the maximum value, the adjacent laser power difference Δp n-1 The data are fitted according to formula (3) for the subsequent values.

[0127] (8) Using formula (4) to calculate the estimated power value p 估 , and the estimated power value p 估 It is displayed as the average laser power in the sub-second level. When the actual measured output power value p 测 And the estimated power value p 估 If the difference is within 2%, stop estimating and measure the actual output power value p 测 Displays the average laser power at the sub-second level.

[0128] (9) Turn off the high-power laser and look for the maximum backscatter monitoring temperature T 监测大 The equilibrium value T after the outlet and inlet temperatures are the same 水平The standard for the outlet and inlet temperatures is to make the difference between the two temperatures less than 0.1°C.

[0129] (10) Calculate the backscatter monitoring temperature rise ΔT 监测 =T 监测大 -T 监测小 , and the temperature rise of water ΔT 总 =T 水平 -T 水小 , and use formula (5) to get the laser energy value.

[0130] (11) Find the sudden rise time t of the photodetector output voltage 升 And the sudden drop time of output voltage t 降 , calculate the laser emission time t = t 降 -t 升 ;

[0131] (12) Calculate the average laser power according to formula (6);

[0132] (13) Use the photodetector to output signals (t1, V1), (t2, V2), ..., (t n ,V n ) Calculate the waveform area

[0133] (14) The laser power distribution curve is obtained using formula (10), which is:

[0134] (15) Place a high-power bulb directly into the absorption cavity, use a high-precision voltmeter to monitor the voltage of the two electrodes of the bulb, use a high-precision voltmeter and a precision resistor to obtain the current of the high-power bulb, and monitor the power of the high-power bulb in real time.

[0135] (16) Repeat steps (2), (3), (4), (9), (10), (11), (12), (13), (14), and (15);

[0136] (17) Integrate the power of the bulb to get the final standard energy E 标 , the energy obtained by the lightweight laser power energy tester is recorded as E 测 , correction coefficient k.

[0137] (18) Multiply the calibration coefficient by the laser energy, average power, and power distribution curve obtained in the above steps to calculate the final result.

[0138] It should be noted that the embodiment of the present invention uses average power to obtain the average power of the entire laser light after the measurement is completed, ignoring the power fluctuations during the entire laser light process. The laser time distribution curve is related to the laser power curve. The laser power time distribution curve is also given after the entire light measurement is completed, specifically to provide details of the power fluctuations during the laser light process. In practical applications, as participants in the measurement process, they prefer to see the power value. Therefore, the embodiment of the present invention uses sub-second laser average power. The sub-second laser average power is also average power, but it only averages the laser power within 1 second, which allows the laser power to be displayed in a more real-time manner.

[0139] The lightweight laser power energy tester of the embodiment of the present invention increases the measurement uncertainty of laser power energy and shortens the response time of laser power by adding an electrical calibration component, adding backscattering monitoring, and adding a power estimation algorithm. When using the same power measurement, it reduces the weight of the laser power energy tester and improves the ease of use of the laser power energy tester.

[0140] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A lightweight laser power energy tester, characterized in that: include: Power energy sensor, data acquisition host and control processing system; including: The power energy probe comprises a laser energy measurement component, which comprises: an energy absorption cavity, a backscattering measurement module, a water cooling module and a temperature difference measurement module, wherein the energy absorption cavity is used to absorb most of the energy of the incident laser, the backscattering measurement module is used to measure a small part of the energy of the incident laser, and the measurement result corresponding to the small part of the energy is compensated to the laser energy corresponding to the majority of the energy; the water cooling module cools the energy in the energy absorption cavity, the water passes through the water cooling module and heats up to generate a temperature difference, and the temperature difference measurement module measures the temperature difference; The data acquisition host comprises a water flow and water temperature difference measuring component, which collects the water flow of the water cooling module and the water temperature difference of the temperature difference measuring module to obtain a measurement result; The control processing system calculates the measurement results of the data acquisition host and the backscattering measurement module to obtain the measured laser energy; the measurement and control results of the water flow and water temperature difference measurement component are combined with the power estimation algorithm to obtain the laser power during the measurement process of the lightweight laser power energy tester.

2. A lightweight laser power energy tester according to claim 1, characterized in that: The power energy probe also includes: an ambient temperature measurement sensor; the data acquisition host includes: a high-precision resistance acquisition card; The ambient temperature measurement sensor and the high-precision resistance acquisition card jointly collect the ambient temperature of the lightweight laser power energy tester; The control processing system determines whether the ambient temperature is too high or too low according to the ambient temperature, and introduces an energy compensation factor in the calculation process of measuring the laser energy.

3. A lightweight laser power energy tester according to claim 1, characterized in that: The power energy probe further comprises: an electrical calibration component; The electrical calibration component is used to provide accurate measurement of energy and calibrate a lightweight laser power energy tester.

4. A lightweight laser power energy tester according to claim 1, characterized in that: The power energy probe also includes: a waveform measurement component; the data acquisition host includes: a photoelectric signal amplification circuit and an acquisition card; The waveform measurement component is used to measure the laser output power fluctuation signal; The photoelectric signal amplification circuit and the acquisition card collect power fluctuation signals; The control processing system calculates the laser emission time according to the power fluctuation signal, and obtains the laser average power by combining the measured laser energy.

5. A lightweight laser power energy tester according to claim 1, characterized in that: The temperature difference measurement module is installed at the water inlet and outlet; The water flow in the energy absorption chamber absorbs the energy of the laser power to increase the temperature. The temperature difference measurement module measures the change in water temperature before and after the water flows through the energy absorption chamber to obtain the temperature difference.

6. A lightweight laser power energy tester according to claim 5, characterized in that: The calculation expression of laser power P is: In formula (1), C represents the specific heat capacity of water, ρ represents the water density, Q represents the water flow rate, ΔT represents the temperature difference between the inlet and outlet water of the power meter, and T 出水 Indicates the outlet temperature, T 入水 Indicates the water inlet temperature.

7. A lightweight laser power energy tester according to claim 1, characterized in that: The power estimation algorithm includes: (1) Record the laser power at different times (t1, p1), (t2, p2), ..., (t n ,p n ); (2) Use formula (2) to calculate the adjacent laser power difference Δp n-1 : Δp n-1 =p n -p n-1 Formula (2) In formula (2), p n represents the laser power at time n, p n-1 represents the laser power at time n-1, and n represents different times; (3) Difference of adjacent laser powers Δp n-1 After reaching the maximum, the difference in adjacent laser powers Δp n-1 The subsequent values ​​are fitted according to formula (3): In formula (3), a and b represent the coefficients that need to be obtained in the end of data fitting; (4) Using formula (4) to calculate the estimated power value p 估 , and the estimated power value p 估 As the average power of the laser in the sub-second level; if the actual measured output power value p corresponding to the test result 测 And the estimated power value p 估 If the difference is within 2%, stop estimating and measure the actual output power value p 测 As the average laser power of the laser at the sub-second level, formula (4) is:

8. A lightweight laser power energy tester according to claim 1, characterized in that: The control processing system also outputs laser energy E and average power P after the measurement. 平均 and the power distribution curve, where: The calculation expression of laser energy E is: E=Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 Formula (5) In formula (5), C represents the specific heat capacity of water, m 水 Indicates the mass of water, ΔT 总 represents the total temperature rise of water, C 监测 Indicates the specific heat capacity of the material used in the backscattering measurement module, m 监测 Indicates the weight of the material used in the backscatter measurement module, ΔT 监测 Represents the temperature rise generated by the backscatter measurement module; Average power P 平均 The calculation expression is: In formula (6), E represents the laser energy, and t represents the laser emission time; The calculation expressions of the power distribution curve include: The detector photoelectric response V(t) is proportional to the laser input power P(t) and is expressed as: v(t)=αP(t) Formula (7) In formula (7), α represents the proportional constant; Integrating formula (7) yields: In formula (8), represents the waveform area S, represents the laser energy E; The laser time distribution function is expressed as: The power distribution curve is obtained according to formula (9).

9. A testing method for a lightweight laser power energy tester, based on a lightweight laser power energy tester according to any one of claims 1 to 8, characterized in that: The test method includes the following steps: Step 1: (11) at equal intervals of time t 间 , record the water inlet temperature T of the water cooling module at different times 入水 and outlet temperature T 出水 , we get (t1,T 入水1 ), (t2,T 入水2 ),……,(t n ,T 入水n );(t1,T 出水1 ), (t2,T 出水2 ),……,(t n ,T 出水n );(12) At equal intervals t 间 , record the backscatter monitoring temperature T of the backscatter measurement module 监测 , we get (t1,T 监测1 ), (t2,T 监测2 ),……,(t n ,T 监测n );(13) At equal intervals t 间 , record the output voltage value V of the photodetector, and obtain (t1, V1), (t2, V2), ..., (t n ,V n ); Step 2: (21) Determine the minimum backscattering monitoring temperature T before the laser emits light 监测小 , and the minimum value of the average temperature of the water outlet and the water inlet T 水小 ; (22) After the laser emits light, it determines the maximum backscattering monitoring temperature T 监测大 , and the equilibrium value T after the outlet and inlet temperatures are the same 水平 ; (23) Calculate the backscatter monitoring temperature rise ΔT 监测 =T 监测大 -T 监测小 , and the temperature rise of water ΔT 总 =T 水平 -T 水小 ; The laser energy E is calculated using formula (5), which is: E = Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 ; Step 3: (31) Determine the sudden rise time t of the output voltage of the photodetector 升 , and the sudden drop time of the output voltage t 降 ; (32) Calculate the laser emission time t = t 降 -t 升 ; (33) Use formula (6) to calculate the average power P 平均 , formula (6) is: Step 4: (41) Using the output voltages (t1, V1), (t2, V2), ..., (t n ,V n ), calculate the waveform area S, where: (42) The power distribution curve is obtained using formula (9), which is:

10. The testing method of a lightweight laser power energy tester according to claim 9, characterized in that: The fifth step is to trace the measurement value through electrical calibration after the measurement is completed. Specifically: (51) A high-power bulb is used as the calibration source. The high-power bulb is directly placed in the energy absorption cavity, and a high-precision voltmeter is used to monitor the voltage of the two electrodes of the high-power bulb; (52) A high-precision voltmeter and a precision resistor are used to obtain the current of the high-power bulb, and the power of the high-power bulb is monitored in real time. The power is integrated to obtain the final standard energy E 标 , the energy of the lightweight laser power energy tester is recorded as E 测 , calibration factor (53) Based on the calibration coefficients, step three and step four, the final results of laser energy, average power, and power distribution curve are obtained.

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