A laser power measuring device and method based on light pressure

Abstract

The application discloses a kind of laser power measuring devices based on light pressure, it is characterized in that, including: windproof cabin, first reflector, second reflector, lightweight double-sided reflector, autocollimator;Double-sided reflector is arranged in windproof cabin, one side surface is laser reflection surface, the other side surface is autocollimator reflection surface, autocollimator is opposite autocollimator reflection surface arrangement, for detecting whether double-sided reflector is stationary stable, first reflector, second reflector are arranged in laser reflection surface side;Windproof cabin is provided with incident window and exit window, first reflector is arranged in the inboard of incident window, second reflector is arranged in the inboard of exit window, the laser to be measured is incident to first reflector via incident window and is reflected to double-sided reflector, after being reflected by double-sided reflector, it is reflected by second reflector, and is emitted by exit window.This application greatly simplifies the traditional high-power laser power measuring device, improves measurement accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical metrology, and relates to a laser power measurement method, in particular to a laser power measurement device and method based on optical pressure. BACKGROUND

[0002] In recent years, with the increasing demand for measuring high-power laser power, the measurement method of high-power laser power has developed and improved a lot. The method of indirectly measuring laser power by measuring laser optical pressure has gradually been concerned by the field of laser power metrology. Compared with the traditional laser power energy measurement method, the optical pressure method has the characteristics of small volume, light weight, etc., and does not need to be traced to the optical quantity, but directly to the force, and the measurement accuracy is greatly improved.

[0003] At present, there are still few devices for measuring optical pressure. The main measurement methods are: 1) measuring laser optical pressure based on measuring the deformation of a thin film stretched by laser irradiation; 2) measuring the acceleration generated after irradiation by calculating the laser irradiation on a lightweight mirror to calculate the laser optical pressure; 3) optical pressure measurement method based on high-precision balance. The method of calculating laser optical pressure by measuring the deformation of the thin film is greatly affected by the laser spot and distribution, and requires a high post-measurement device. The method of measuring laser optical pressure by measuring acceleration is very strict in the mass of the key components of the measurement device due to the small value of the optical pressure, and usually uses carbon nanotubes. The method of measuring optical pressure based on high-precision balance is difficult to measure small power light sources.

[0004] The patent "CN107588874B" of Northwest Industrial University has been authorized for measuring laser optical pressure based on measuring the deformation of a thin film stretched by laser irradiation. The patent "CN113138043A" of Tsinghua University has been accepted for the method of calculating the laser optical pressure by measuring the acceleration generated after irradiation by calculating the laser irradiation on a lightweight mirror. The patent "non-attenuating meter for determining optical energy of laser light" of the United States has mentioned the optical pressure measurement method of high-precision balance. SUMMARY

[0005] (I) Invention purpose

[0006] The purpose of the present application is to provide a laser power measurement device and method based on optical pressure. Compared with the traditional laser power energy measurement method, the optical pressure method has the characteristics of small volume, light weight, etc., and does not need to be traced to the optical quantity, but directly to the force, and the measurement accuracy is greatly improved.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, the application provides a laser power measuring device based on light pressure, which comprises a windproof cabin, a first reflector, a second reflector, a lightweight double-sided reflector and a collimator; the double-sided reflector is arranged in the windproof cabin, one side surface of the double-sided reflector is a laser reflection surface, the other side surface is a collimator reflection surface, the collimator is arranged opposite to the collimator reflection surface and is used for detecting whether the double-sided reflector is stationary and stable, the first reflector and the second reflector are arranged on one side of the laser reflection surface; an incident window and an emission window are arranged on the windproof cabin, the first reflector is arranged inside the incident window, the second reflector is arranged inside the emission window, the laser to be measured is incident to the first reflector through the incident window and is reflected to the double-sided reflector, is reflected through the second reflector after being reflected by the double-sided reflector and is emitted through the emission window.

[0009] The application also provides a laser power measuring method based on light pressure, and the measuring process is as follows:

[0010] Firstly, the incident angle of the laser to be measured is adjusted, so that the incident laser and the lightweight double-sided reflector form a certain incident angle θ; after the incident angle is adjusted, the laser to be measured is turned off, the collimator is turned on, and whether the double-sided reflector is stationary and stable is detected;

[0011] Then, after the double-sided reflector is stationary and stable, the laser to be measured is turned on, the angle change of the lightweight double-sided reflector is observed through the collimator, when the lightweight double-sided reflector is stable again, the angle change value α of the double-sided reflector on the collimator is read;

[0012] Finally, the laser to be measured is turned off, and the laser power to be measured is calculated.

[0013] (Three) beneficial effects

[0014] The laser power measuring device and the measuring method based on light pressure provided by the above technical solution calculate the light pressure by measuring the position and the angle change of the laser irradiated on the hoisted reflector, the energy distribution of the laser spot does not affect the measurement result because the reflector is not a thin film or other easily variable material, the traditional high-power laser power measuring device is greatly simplified, and the measurement precision is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The composition principle diagram of the laser power measuring device based on light pressure of the embodiment of the application is shown. DETAILED DESCRIPTION

[0016] In order to make the purpose, content and advantages of the application more clear, the specific implementation manner of the application is further described in detail below in combination with the drawings and the embodiments.

[0017] As Figure 1The laser power measuring device based on light pressure in the embodiment has high sensitivity and is not affected by factors such as spot distribution. The measuring device comprises a windproof cabin, a first mirror, a second mirror, a lightweight double-sided mirror and a collimator. The double-sided mirror is arranged in the windproof cabin, one side surface of the double-sided mirror is a laser reflection surface, the other side surface is a collimator reflection surface, the collimator is arranged opposite to the collimator reflection surface, and the first mirror and the second mirror are arranged on the side of the laser reflection surface. An incident window and an exit window are arranged on the windproof cabin, the first mirror is arranged inside the incident window, the second mirror is arranged inside the exit window, the laser to be measured is incident on the first mirror through the incident window and is reflected to the double-sided mirror, is reflected through the second mirror after being reflected by the double-sided mirror, and is emitted through the exit window.

[0018] A support frame is arranged in the windproof cabin, and a flexible suspension line is hung on the support frame. The double-sided mirror is hung and arranged by the flexible suspension line.

[0019] The reflectivity of the laser reflection surface of the first mirror, the second mirror and the double-sided mirror is 99.9%. The measurement accuracy of the collimator reaches the second level. In addition, high-transmittance plane glass is installed on the incident window and the exit window of the windproof cabin, and the transmittance requirement is better than 99.9%.

[0020] When measuring the laser power, first, the incident angle of the laser to be measured is adjusted, for example, Figure 1 , to ensure that the incident laser has a certain incident angle θ with the lightweight double-sided mirror. After adjusting the incident angle, the laser to be measured is turned off, the collimator is turned on, and whether the double-sided mirror is stationary and stable is detected. The angle change of the double-sided mirror displayed in real time by the collimator can be read to determine whether the double-sided mirror is in a stationary and stable state.

[0021] After the double-sided mirror is stationary and stable, the laser to be measured is turned on, and then the angle change of the lightweight double-sided mirror is observed by the collimator. When the lightweight double-sided mirror is stable again, the angle change value α of the double-sided mirror on the collimator is read. At this time, the test is completed, and the laser to be measured is turned off. The acting force of the laser to be measured on the lightweight mirror and the laser power to be measured can be calculated by the formula.

[0022] The laser power measuring method based on light pressure in the embodiment calculates the light pressure by measuring the angle change of the hoisted lightweight double-sided mirror after laser irradiation. The method comprises the following steps:

[0023] Step 1: Turn on the collimator, monitor the angle change of the double-sided mirror by the collimator, and set the angle of the collimator to zero when the angle on the collimator is not changing.

[0024] Step 2: Adjust the incident light to ensure that the incident light is horizontally incident and can be emitted through the exit window after reflection.

[0025] Step 3: After the autocollimator reading is stable, record the autocollimator angle change value alpha;

[0026] Step 4: Calculate the laser power according to the formula Gamma is the reflectivity of the laser reflecting surface of the two-mirror, c is the speed of light, m is the mass of the two-mirror, g is the acceleration of gravity, alpha is the angle change value of the two-mirror, and theta is the determined incidence angle formed by the incident laser and the light two-mirror.

[0027] Through the above device and method, the user can measure the power of high-power laser, and the following purposes are achieved:

[0028] 1) The present application can measure the power of different power lasers, and the device is simple and easy to realize.

[0029] 2) The present application improves the accuracy of measuring the power of high-power laser.

[0030] 3) The device can also measure the optical pressure.

[0031] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. An optical pressure based laser power measurement device, characterized by, The application relates to a windproof cabin, a first reflector, a second reflector, a lightweight double-sided reflector and a collimator; the double-sided reflector is arranged in the windproof cabin, one side surface of the double-sided reflector is a laser reflection surface, the other side surface is a collimator reflection surface, the collimator is arranged opposite to the collimator reflection surface and is used for detecting whether the double-sided reflector is stationary and stable, the first reflector and the second reflector are arranged on the laser reflection surface side; an incident window and an emission window are arranged on the windproof cabin, the first reflector is arranged on the inner side of the incident window, the second reflector is arranged on the inner side of the emission window, the laser to be detected is incident to the first reflector through the incident window and is reflected to the double-sided reflector, is reflected through the double-sided reflector, is reflected through the second reflector and is emitted through the emission window; A supporting frame is arranged in the windproof cabin, a flexible suspension line is hung on the supporting frame, and the double-sided reflector is hung and arranged by the flexible suspension line; The reflectivity of the first reflector, the second reflector and the laser reflection surface of the double-sided reflector is 99.9%; the measurement accuracy of the collimator is second level; The incident window and the emission window of the windproof cabin are both installed with high-transmittance plane glass, and the transmittance is not less than 99.9%. The measurement process is as follows:

2. A method of laser power measurement based on optical pressure based on the measuring device of claim 1, characterized by, Firstly, the incident angle of the laser to be detected is adjusted, so that the incident laser and the lightweight double-sided reflector form a certain incident angle theta; after the incident angle is adjusted, the laser to be detected is closed, the collimator is opened, and whether the double-sided reflector is stationary and stable is detected; Then, after the double-sided reflector is stationary and stable, the laser to be detected is opened, the angle change of the lightweight double-sided reflector is observed through the collimator, when the lightweight double-sided reflector is stable again, the angle change value alpha of the double-sided reflector on the collimator is read; Finally, the laser to be detected is closed, and the power of the laser to be detected is calculated; Whether the double-sided reflector is in a stationary and stable state is determined by reading the angle change of the double-sided reflector displayed by the collimator in real time. ​ Laser power

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