Lightweight laser power energy tester and testing method thereof

Abstract

The application provides a lightweight laser power energy tester and a testing 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, which comprises an energy absorption cavity, a backscattering measurement module, a water cooling module and a temperature difference measurement module. The data acquisition host comprises a water flow and water temperature difference measurement assembly. The control processing system calculates the measured laser energy from the measurement results. The testing method comprises recording the temperature of the water inlet and outlet, the backscattering monitoring temperature and the output voltage value of the photodetector; determining the minimum value, the maximum value, the temperature rise, the water temperature rise and the laser energy; determining the sudden rise / fall time of the output voltage of the photodetector, the light output time and the average power; calculating the waveform area to obtain the power distribution curve. The application adopts a power estimation algorithm to give sub-second laser average power in the measurement process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical metrology, and particularly relates to a lightweight laser power energy tester and a testing method thereof. BACKGROUND

[0002] The laser power energy tester is mainly used for measuring the light power energy of high-power laser. The laser power energy tester converts the laser power energy into heat, and calculates the laser power energy by measuring the energy temperature difference. In recent years, with the development of technology, the core devices of high-power laser are constantly matured, and the power energy of laser light is constantly improved.

[0003] The traditional laser power energy tester with all-solid-state design not only increases the volume and weight with the increase of the measured power energy, but also is more suitable for giving the laser energy and power of this measurement after the light is turned off. In addition, the laser power energy tester with all-solid-state design is not accurate in the measurement of sub-second laser average power at the beginning of measurement due to the small temperature difference caused by laser, and is also not accurate in the measurement of sub-second laser average power at the end of measurement due to high temperature and serious heat loss. Therefore, the traditional laser power energy tester cannot meet the demand of sub-second laser average power measurement during the light emission of laser.

[0004] In recent years, in order to overcome the volume and weight disadvantages of the laser power energy tester with all-solid-state design, the laser power energy tester with liquid cooling is adopted. Since the laser power energy tester with liquid cooling increases the volume of cooling water to increase the measurable laser energy, the volume and weight of the laser power energy tester with liquid cooling no longer increase with the increase of the measured laser power energy. However, the temperature stabilization time of the laser power energy tester with liquid cooling is longer, and the laser power energy tester with liquid cooling cannot realize the measurement of sub-second laser average power. SUMMARY

[0005] The present application aims to solve the problems of volume and weight and long measurement time in the prior art, and provides a lightweight laser power energy tester and a testing method thereof. The power estimation algorithm is used to shorten the response time of the laser power energy tester, and the sub-second laser average power is given during the measurement process.

[0006] To achieve the above-mentioned purpose, the technical solution provided by the present application is as follows:

[0007] On the one hand, the present application provides a lightweight laser power energy tester, which comprises a power energy probe, a data acquisition host and a control processing system, wherein:

[0008] The power energy probe comprises a laser energy measurement assembly, which comprises an energy absorption cavity, a backscattering measurement module, a water cooling module and a temperature difference measurement module, the energy absorption cavity is used for absorbing most of the energy of the incident laser, the backscattering measurement module is used for measuring a small part of the energy of the incident laser, and the measurement result corresponding to the small part of the energy is compensated into the laser energy corresponding to the most part of the energy; the water cooling module cools the energy in the energy absorption cavity, the water is heated through the water cooling module 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 measurement assembly, which acquires the water flow of the water cooling module and the water temperature difference of the temperature difference measurement module to obtain a measurement result;

[0010] The measurement result of the data acquisition host and the measurement result of the backscattering measurement module are calculated by the control processing system to obtain a measured laser energy; the measurement and control result of the water flow and water temperature difference measurement assembly is combined with a power estimation algorithm to obtain laser power in the measurement process of the lightweight laser power energy tester.

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

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

[0013] The control processing system judges whether the temperature of the environment 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 manner of the present application, the power energy probe further comprises an electrical calibration assembly;

[0015] The electrical calibration assembly is used for providing an accurately measured energy to calibrate the lightweight laser power energy tester.

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

[0017] The waveform measurement assembly is used for measuring a laser output power fluctuation signal;

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

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

[0020] In one specific implementation of the present application, the temperature difference measuring module is installed at the water inlet and outlet based on one aspect.

[0021] The water flow absorbs the energy of the laser power in the energy absorption cavity, and the temperature rises, and the temperature difference measuring module measures the temperature change of the water before and after the water flow passes through the energy absorption cavity to obtain the temperature difference.

[0022] In one specific implementation of the present application, the calculation expression of the laser power P is based on one aspect.

[0023]

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

[0025] In one specific implementation of the present application, the power estimation algorithm includes based on one aspect.

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

[0027] (2) Calculate the adjacent laser power difference Δp n-1 using formula (2):

[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) After the adjacent laser power difference Δp n-1 reaches the maximum, the adjacent laser power difference Δp n-1 and the values after it are fitted according to formula (3):

[0031]

[0032] In formula (3), a and b represent the coefficients finally obtained by data fitting.

[0033] (4) The estimated power value p is calculated using formula (4). 估 And with the estimated power value p 估 The average laser power at the sub-second level; if the actual measured output power value p corresponds to the test result... 测 Compared with the estimated power value p 估 If the difference is within 2%, stop estimating and use the actual measured output power value p. 测 As the average laser power at the sub-second level; Formula (4) is:

[0034] Based on one aspect, in one 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 power distribution curves, where:

[0035] The expression for calculating 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 ΔT represents the mass of water. 总 The total temperature rise of water, C 监测 This indicates the specific heat capacity of the material used in the backscattering measurement module, m. 监测 The weight of the material used in the backscattering measurement module is represented by ΔT. 监测 This indicates the temperature rise generated by the backscattering measurement module;

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

[0039]

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

[0041] The calculation formula for the power distribution curve includes:

[0042] The detector's photoelectric response v(t) is proportional to the laser input power P(t), expressed as:

[0043] v(t)=αP(t) Formula (7)

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

[0045] Integrating equation (7) yields:

[0046]

[0047] In formula (8), S represents the area of ​​the waveform. Indicates 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 also provides a testing method for a lightweight laser power energy tester. Based on the above-mentioned aspect of the lightweight laser power energy tester, the testing method includes the following steps:

[0052] Step 1, (11) according to equal intervals t 间 Record the inlet temperature T of the water-cooled 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) According to equal intervals t 间 Record the backscattering monitoring temperature T of the backscattering measurement module. 监测 We get (t1,T) 监测1 ), (t2,T 监测2 ), ..., (t n ,T 监测n (13) According to equal intervals t 间 Record the output voltage V of the photodetector to 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 T of the average temperature of the inlet and outlet water. 水小 (22) Determine the maximum backscattering temperature T after the laser beam is emitted. 监测大 And the equilibrium value T after the inlet and outlet temperatures are the same. 水平 (23) Calculate the backscattering 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 t of the output voltage 降 (32) Calculate the laser emission time t = t 降 -t 升 (33) The average power P is calculated using formula (6). 平均 Formula (6) is:

[0055] Step 4, (41) Using the output voltages (t1, V1), (t2, V2), ..., (t1) from Step 1. 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 further included: after the measurement is completed, traceability of the measurement value is performed through electrical calibration; specifically:

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

[0058] The advantages of this invention are:

[0059] 1. This invention utilizes a power prediction method to shorten the response time of a laser power energy tester, providing sub-second average laser power during the measurement process.

[0060] 2、The present application increases the electric calibration component, guarantees the energy source of laser to give the standard energy traceability, voltage, resistance, time can be traced to the superior measurement mechanism, ensures the accurate value.

[0061] 3、The present application increases the backscattering monitoring module, increases the power estimation algorithm to improve the measurement uncertainty of laser power energy, shortens the response time of laser power, reduces the weight of laser power energy tester under the same power measurement, improves the use convenience of laser power energy tester.

[0062] Additional aspects and advantages of the present application will be described in the following description, become apparent from the following description, or be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0063] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0064] Figure 1 The present application provides a kind of principle block diagram of lightweight laser power energy tester;

[0065] Figure 2 The present application provides a kind of internal structure diagram of lightweight laser power energy tester;

[0066] Figure 3 The present application provides a kind of laser energy traceability diagram of lightweight laser power energy tester. DETAILED DESCRIPTION

[0067] The embodiments of the present application are described in detail below, which are exemplary, and are intended to explain the present application, and cannot be understood as the limitation of the present application.

[0068] Please refer to Figure 1 The embodiment of the present application discloses a kind of lightweight laser power energy tester, including: (1) power energy probe, (2) data acquisition host and (3) control processing system;Wherein:

[0069] (1) the power energy probe comprises a laser energy measurement assembly, and the laser energy measurement assembly comprises an energy absorption cavity, a backscattering measurement module, a water cooling module and a temperature difference measurement module; the energy absorption cavity is used for absorbing most of the energy of incident laser; the backscattering measurement module is used for measuring a small part of the energy of the incident laser, and the measurement result corresponding to the small part of the energy is compensated into the laser energy corresponding to the most part of the energy; the water cooling module cools the energy in the energy absorption cavity, the water is heated through the water cooling module 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 application is installed at the water inlet and outlet; the water flow of the energy absorption cavity absorbs the energy of the laser power to increase the temperature, the temperature difference measurement module measures the change of the water temperature before and after the water flow passes through the energy absorption cavity, and the temperature difference is obtained.

[0070] Preferably, in the laser energy measurement assembly of the embodiment of the present application, the energy absorption cavity is mainly used for absorbing the energy of incident laser, most of the incident laser is absorbed by the energy absorption cavity, only a small part is measured by the backscattering measurement module, and the measurement result is compensated into the laser energy absorbed by the energy absorption cavity. The energy absorption cavity of the embodiment of the present application is cooled by the water cooling module, the temperature of the water is increased after passing through the water cooling module to generate a temperature difference, and the water flow and the temperature difference of the water flowing through the water cooling module are measured by the water flow and water temperature difference measurement assembly 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 assembly are calculated to obtain the measured laser energy. The measurement result of the water flow and water temperature difference measurement assembly itself is combined with the power estimation algorithm to give the laser power in the measurement process. The signal of the environmental temperature measurement assembly of the embodiment of the present application is collected by a high-precision resistance collection card, and is used for measuring the environmental temperature of the lightweight laser power energy tester. If the environmental temperature is too high or too low, an energy compensation factor needs to be introduced in the calculation of the laser energy.

[0071] Please continue to refer to Figure 1 In addition to the laser energy measurement assembly, the power energy probe described above further comprises an environmental temperature measurement sensor; the environmental temperature measurement sensor and the high-precision resistance collection card in the (2) data acquisition host jointly collect the environmental temperature of the lightweight laser power energy tester.

[0072] In addition, the power energy probe further comprises an electric calibration component and a waveform measurement component; the electric calibration component is used for providing precisely measured energy to calibrate the lightweight laser power energy tester; and the waveform measurement component is used for measuring a laser output power fluctuation signal.

[0073] The electric calibration component of the embodiment of the present application is composed of a power monitorable light source and a power supply system thereof, and is mainly used for providing precisely measured energy to calibrate the lightweight laser power energy meter. Figure 3 The embodiment of the present application uses laser energy tracing, and can calibrate the power energy at any time.

[0074] (2) The data acquisition host computer comprises a water flow and water temperature difference measurement component, which acquires the water flow of the water cooling module and the water temperature difference of the water temperature difference measurement module to obtain a measurement result.

[0075] Please continue to refer to Figure 1 In addition to the water flow and water temperature difference measurement component, the data acquisition host computer further comprises a high-precision resistance acquisition card, (1) the environmental temperature measurement sensor in the power energy probe and the high-precision resistance acquisition card jointly acquire the environmental temperature of the lightweight laser power energy tester; (3) the control processing system judges whether the environmental temperature is too high or too low, and introduces an energy compensation factor in the calculation process of measuring the laser energy.

[0076] Further, please continue to refer to Figure 3 The data acquisition host computer of the embodiment of the present application further comprises a photoelectric signal amplification circuit and an acquisition card; the photoelectric signal amplification circuit and the acquisition card acquire the power fluctuation signal; (3) the control processing system calculates the laser light emission time according to the power fluctuation signal, and obtains the average laser power in combination with the measured laser energy.

[0077] The embodiment of the present application gives the laser energy, the average power and the power distribution curve after the measurement is completed; and the sub-second laser average power is given during the measurement process. The embodiment of the present application shortens the response time of the laser power energy tester by using the power estimation algorithm, and can calibrate the laser power energy tester on site.

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

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

[0080]

[0081] In formula (1), C represents the specific heat capacity of water, p represents the water density, Q represents the water flow, AT represents the temperature difference of the power meter in and out of the water, T 出水 represents the outlet water temperature, and T 入水 represents the inlet water temperature.

[0082] (32) The power estimation algorithm of the embodiment of the present application comprises:

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

[0084] (322) Calculate the adjacent laser power difference Δp n-1 using formula (2):

[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) After the adjacent laser power difference Δp n-1 reaches the maximum, the adjacent laser power difference Δp n-1 and the values after it are fitted according to formula (3):

[0088]

[0089] In formula (3), a and b represent the coefficients finally obtained by data fitting;

[0090] (324) Calculate the estimated power value p 估 using formula (4), and use the estimated power value p 估 as the laser average power of the laser sub-second; if the actual measurement output power value p 测The estimated power value p 估 is within 2%, stop the estimation, and use the actual measured output power value p 测 as the average power of the laser in the sub-second level; formula (4) is:

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

[0092] (331) The calculation expression of the 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 represents the mass of water, ΔT 总 represents the total temperature rise of water, C 监测 represents the specific heat capacity of the material used by the backscattering measurement module, m 监测 represents the weight of the material used by the backscattering measurement module, ΔT 监测 represents the temperature rise generated by the backscattering measurement module;

[0095] (332) The calculation expression of the average power P 平均 is:

[0096]

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

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

[0099] The photoelectric response v(t) of the detector is proportional to the laser input power P(t), which is represented as:

[0100] v(t) = αP(t) Formula (7)

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

[0102] Integrating formula (7) gives:

[0103]

[0104] In formula (8), S represents the waveform area, 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 provided by the embodiment of the present application adopts a water cooling structure. The laser power makes the temperature of the water flowing outside the energy absorption cavity rise, and the flowing 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 produces a temperature difference before and after flowing through the energy absorption cavity. Temperature measuring sensors are installed at the water inlet and outlet to accurately measure the water temperature change.

[0109] Based on the above-mentioned lightweight laser power energy tester, the embodiment of the present application further discloses a test method of the lightweight laser power energy tester. Since the laser power energy tester adopting the calorimetric method has a relatively long response time, the time from the laser light emission to the stable sub-second laser average power reading given by the laser power energy tester is generally greater than 30s. In order to give the measured laser power value before the laser power energy tester reaches stability, the embodiment of the present application estimates the laser power by using the current measurement result in combination with a power estimation algorithm. The test method estimates the power by using the power output curve before the stable output of the power energy tester, which is approximately an exponential curve. Specifically:

[0110] The test method of the embodiment of the present application comprises the following steps:

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

[0112] Step 2, (21) determining the minimum value T 监测小 of the backscattering monitoring temperature and the minimum value T 水小 of the average temperature of the outlet and the inlet before the laser light is emitted; (22) determining the maximum value T 监测大 of the backscattering monitoring temperature and the equilibrium value T 水平 of the temperature of the outlet and the inlet after the laser light is emitted; (23) calculating the temperature rise ΔT 监测 of the backscattering monitoring temperature = T 监测大 -T 监测小 , and the temperature rise ΔT 总 of the water = T 水平 -T 水小 ; using formula (5) to calculate the laser energy E, formula (5) is: E = Cm 水 ΔT 总 +C 监测 m 监测 ΔT 监测 ;

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

[0114] Step 4, (41) using the output voltage (t1, V1), (t2, V2), …, (t n ,V n ) of step 1 to calculate the waveform area S, wherein: (42) using formula (9) to obtain the power distribution curve, formula (9) is:

[0115] Step 5, after the measurement is completed, the value traceability is performed through electrical calibration; specifically:

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

[0117] More specifically, after the test is completed, the value traceability is performed by the electrical calibration assembly using the above-mentioned test method. In general laser power energy calibration, the electrical calibration usually uses electrical heating method. In high-power energy calibration, due to the more complex system, it is difficult to accurately obtain the photoelectric non-equivalence coefficient generated by the electrical heating method, so the above-mentioned high-power bulb is used as a calibration source in the embodiment of the present application. Please continue to refer to Figure 3 In order to ensure that the generated energy can be traced, the traceability of the standard energy is given, the voltage, resistance and time can be traced to the upper-level measurement organization, and the value accuracy is ensured.

[0118] Please refer to Figure 2 The lightweight laser power energy tester of the embodiment of the present application comprises a water container, a temperature sensor and a power energy probe (probe). The power energy probe (probe) comprises a temperature sensor, a hemispherical reflector, a rear absorption plate, a main absorption cylinder 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 exchanging heat with the main absorption cylinder enters the water container from the water outlet. The incident laser is arranged in front of the incident window to provide measurement laser. The laser is incident on the hemispherical reflector in the main absorption cylinder, scattered to the inner wall of the absorption cavity by the hemispherical reflector, and the light reflected to the inner wall of the absorption cavity is mostly absorbed, only a small part of the light is scattered twice. A part of the twice-scattered light escapes from the front laser incident port of the absorption cavity, and the power of this part of the escaped light is compensated to the laser energy absorbed by the energy absorption cavity in proportion according to the measurement result of the backscattering measurement module.

[0119] Please continue to refer to Figure 2 Taking a high-power laser (preferably a 10000-watt laser) as an example, combined with Figure 2 The application example of the test method of the embodiment of the present application is disclosed. The test method of the application example comprises the following steps:

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

[0121] (2) Turn on the water circulation system corresponding to the water container, and turn on the main machine of the lightweight laser power energy tester to preheat.

[0122] (3) Record the inlet and outlet water temperature T 间 , T 入水 , T出水 and backscattering 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 interval time t 间 , record the output voltage value of photodetector (t1, V1), (t2, V2), … (t n , V3). Find the minimum value of backscattering monitoring temperature T 监测小 and the minimum value of average temperature of outlet and inlet T 水小 .

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

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

[0125] (6) Calculate the adjacent laser power difference Δp n-1 using formula (2).

[0126] (7) When the adjacent laser power difference Δp n-1 reaches the maximum value, the adjacent laser power difference Δp n-1 and the values after it are fitted according to formula (3).

[0127] (8) Calculate the estimated power value p 估 using formula (4), and take the estimated power value p 估 as the average power of the laser sub-second laser to display. When the actual measured output power value p 测 differs from the estimated power value p 估 by 2% or less, stop the estimation, and take the actual measured output power value p 测 as the average power of the laser sub-second laser to display.

[0128] (9) Turn off the high-power laser, find the maximum value of backscattering monitoring temperature T 监测大 and the balance value T 水平 after the outlet and inlet temperatures are the same.The standard that the outlet and inlet temperatures are the same ensures that the temperature difference between the two is less than 0.1℃.

[0129] (10) Calculate the backscattering 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 value is obtained using formula (5).

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

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

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

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

[0134] (15) Place the high-power bulb directly into the absorption chamber, use a high-precision voltmeter to monitor the voltage between 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), (15);

[0136] (17) Integrate the power of the bulb to obtain the final standard energy E. 标 The energy obtained by the lightweight laser power energy meter is denoted as E. 测 , correction factor 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 application uses the average power to obtain the average power of the entire laser light output after the measurement is completed, and ignores the power fluctuation in the entire laser light output process. The laser time distribution curve is related to the laser power curve, and the laser power time distribution curve is also given after the entire light output measurement is completed. Specifically, it is to give the details of the power fluctuation in the laser light output process. In practical application, as a test person, it is more desirable to see the power value during the measurement process, therefore, the sub-second laser average power is adopted in the embodiment of the present application, which is also an average power, but only averages the laser power in 1s, so that the laser power can be displayed more in real time.

[0139] The lightweight laser power energy tester provided by the embodiment of the present application increases the electric calibration component, increases the backscattering monitoring, increases the power estimation algorithm, improves the measurement uncertainty of the laser power energy, shortens the response time of the laser power, reduces the weight of the laser power energy tester under the condition of using the same power measurement, and improves the use convenience of the laser power energy tester.

[0140] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A lightweight laser power energy tester, characterized in that, include: Power energy probe, data acquisition host, and control and processing system; among which: The power energy probe includes 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. The energy absorption cavity absorbs most of the energy of the incident laser, and the backscattering measurement module measures a small portion of the energy of the incident laser, compensating the measurement result of the small portion of energy into the laser energy corresponding to the majority of the energy. The water-cooling module cools the energy in the energy absorption cavity, and the water is heated by the water-cooling module to generate a temperature difference, which is measured by the temperature difference measurement module. The data acquisition host includes a water flow rate and water temperature difference measurement component. The water flow rate and water temperature difference measurement component acquires the water flow rate of the water cooling module and the water temperature difference of the temperature difference measurement module to obtain the measurement results. The control and processing system calculates the measured laser energy by combining the measurement results from the data acquisition host and the backscattering measurement module; the measurement and control results from the water flow and water temperature difference measurement components are combined with the power estimation method to obtain the laser power during the measurement process of the lightweight laser power energy tester.

2. The 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 acquire the ambient temperature of the lightweight laser power energy tester. The control and processing system determines whether the ambient temperature is too high or too low based on the ambient temperature, and introduces an energy compensation factor during the calculation of laser energy measurement.

3. A lightweight laser power energy tester according to claim 1, characterized in that, The power energy probe also includes: an electrical calibration component; The electrical calibration component is used to provide accurately measured energy for calibrating a lightweight laser power energy meter.

4. A lightweight laser power energy tester according to claim 1, characterized in that, The power energy probe further 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 acquire power fluctuation signals; The control and processing system calculates the laser emission time based on the power fluctuation signal and obtains the average laser power by measuring the 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 inlet and outlet of the water; The water flow in the energy absorption cavity absorbs the energy of the laser power, causing its temperature to rise. The temperature difference measurement module measures the temperature change of the water before and after it passes through the energy absorption cavity, thus obtaining the temperature difference.

6. A lightweight laser power energy tester according to claim 5, characterized in that, The expression for calculating laser power P is: In formula (1), C represents the specific heat capacity of water, ρ represents the density of water, 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 This indicates the inlet water temperature.

7. A lightweight laser power energy tester according to claim 1, characterized in that, Power estimation methods include: (1) Record the laser power at different times (t1, p1), (t2, p2), ..., (t... n ,p n ); (2) Calculate the power difference Δp between adjacent lasers using formula (2). n-1 : Δp n-1 =p n -p n-1 Formula (2) In formula (2), p n p represents the laser power at time n. n-1 This represents the laser power at time n-1, where n represents different times; (3) Power difference between adjacent lasers Δp n-1 After reaching its maximum, the power difference Δp between adjacent laser beams n-1 The values ​​thereafter are fitted using formula (3): In formula (3), a and b represent the coefficients that need to be obtained for the final data fitting; (4) The estimated power value p is calculated using formula (4). 估 and with the estimated power value p 估 The average laser power at the sub-second level; if the actual measured output power value p corresponds to the test result... 测 Compared with the estimated power value p 估 If the difference is within 2%, stop estimating and use the actual measured output power value p. 测 As the average laser power at the sub-second level; Formula (4) is:

8. A lightweight laser power energy tester according to claim 1, characterized in that, The control and processing system also outputs laser energy E and average power P after the measurement is completed. 平均 and power distribution curves, where: The expression for calculating 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 ΔT represents the mass of water. 总 The total temperature rise of water, C 监测 This indicates the specific heat capacity of the material used in the backscattering measurement module, m. 监测 The weight of the material used in the backscattering measurement module is represented by ΔT. 监测 This indicates the temperature rise generated by the backscattering measurement module; Average power P 平均 The calculation expression is: In formula (6), E represents laser energy and t represents laser emission time; The calculation formula for the power distribution curve includes: The detector's photoelectric response V(t) is proportional to the laser input power P(t), expressed as: v(t)=αP(t) Formula (7) In formula (7), α represents the proportionality constant; Integrating equation (7) yields: In formula (8), S represents the area of ​​the waveform. Indicates 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 the lightweight laser power energy tester according to any one of claims 1-8, characterized in that, The testing method includes the following steps: Step 1, (11) according to equal intervals t 间 Record the inlet temperature T of the water-cooled module at different times. 入水 and outlet temperature T 出水 , thus obtaining (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) According to equal intervals t 间 Record the backscattering monitoring temperature T of the backscattering measurement module. 监测 , thus obtaining (t1,T 监测1 ), (t2,T 监测2 ), ..., (t n ,T 监测n (13) According to equal intervals t 间 Record the output voltage V of the photodetector to 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 T of the average temperature of the inlet and outlet water. 水小 (22) Determine the maximum backscattering temperature T after the laser beam is emitted. 监测大 And the equilibrium value T after the inlet and outlet temperatures are the same. 水平 (23) Calculate the backscattering 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 t of the output voltage 降 (32) Calculate the laser emission time t = t 降 -t 升 (33) The average power P is calculated using formula (6). 平均 Formula (6) is: Step 4, (41) Using the output voltages (t1, V1), (t2, V2), ..., (t1) from Step 1. 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, It also includes step five: After the measurement is completed, traceability of the measurement value is performed through electrical calibration; specifically: (51) A high-power bulb is used as the calibration source. The high-power bulb is placed directly into the energy absorption cavity, and the voltage between the two electrodes of the high-power bulb is monitored using a high-precision voltmeter. (52) The current of the high-power bulb is obtained using a high-precision voltmeter and a precision resistor. The power of the high-power bulb is monitored in real time, and the power is integrated to obtain the final standard energy E. 标 The energy of the lightweight laser power energy meter is denoted as E. 测 Calibration coefficient (53) Based on the calibration coefficient, step three and step four, the final results of laser energy, average power and power distribution curve are obtained.

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