阅读说明：本技术 大口径熔石英玻璃低损伤阈值缺陷的测量装置和测量方法 (Measuring device and measuring method for low-damage threshold defect of large-caliber fused quartz glass ) 是由 李灵巧 刘世杰 邵建达 王圣浩 于 2019-10-10 设计创作，主要内容包括：一种大口径熔石英元件低阈值缺陷的测量装置和测量方法,系统通过探测缺陷的荧光光谱,来识别大口径熔石英元件上的低阈值缺陷。与现有普遍采用的光热弱吸收测量方法相比,本发明可以把低阈值缺陷的测量速度提高上万倍。(measurement devices and methods for the low threshold defect of the large-caliber fused quartz element, the system identifies the low threshold defect on the large-caliber fused quartz element by detecting the fluorescence spectrum of the defect.)

The measuring device for the low threshold defect of large-caliber fused silica glass is characterized by comprising a two-dimensional mechanical scanning mechanism (1), a laser light source (3), a light filter (4), a spectrometer (5), a stepping motor controller (6), a data acquisition unit (7), a laser controller (8) and a computer (9), wherein the two-dimensional mechanical scanning mechanism (1) is used for placing the large-caliber fused silica glass (2) to be measured, laser emitted by the laser light source (3) irradiates on the surface of the large-caliber fused silica glass (2) to be measured, the fluorescence direction emitted by the surface defect of the large-caliber fused silica glass (2) to be measured is sequentially the light filter (4) and the spectrometer (5), the output end of the spectrometer (5) is connected with the input end of the computer (9), and the output end of the computer (9) is respectively connected with the control end of the two-dimensional mechanical scanning mechanism (1) through the stepping motor controller (6), and the laser controller (8) is connected with the control end of the laser light source (3).

2. The method for measuring the large-caliber fused silica glass low-threshold defect by using the measuring device of the large-caliber fused silica glass low-threshold defect as claimed in claim 1, characterized by comprising the following steps:

1) placing the large-caliber fused quartz glass (2) to be detected on the two-dimensional mechanical scanning mechanism (1), irradiating the laser output by the laser source (3) on the surface of the large-caliber fused quartz glass (2) to be detected, and adjusting the spectrometer (5) and the optical filter (4) to align to the fluorescence emitted by the surface defect of the large-caliber fused quartz glass (2) to be detected;

2) starting the computer (9), wherein under the control of the computer (9), the stepping motor controller (6) controls the two-dimensional mechanical scanning mechanism (1) to move the large-caliber fused quartz glass (2) to be detected to an initial position, laser output by the laser source (3) irradiates the initial position on the surface of the large-caliber fused quartz glass (2) to be detected, the position is N-1, and the number of positions irradiated by the large-caliber fused quartz glass (2) to be detected in a laser scanning mode is N;

3) under the control of the computer (9), the laser output by the laser source (3) irradiates the position n on the surface of the large-caliber fused quartz glass (2) to be measured, and the spectrometer (5) measures the fluorescence spectrum emitted by the position n on the surface of the large-caliber fused quartz glass (2) to be measured and inputs the fluorescence spectrum into the computer (9);

4) the computer (9) judges whether the position n has a fluorescence spectrum corresponding to the low threshold defect, if so, the computer (9) records the coordinate of the position n, namely the position has the low threshold defect;

5) the computer (9) controls the two-dimensional mechanical scanning mechanism (1) through the stepping motor controller (6), moves the large-caliber fused quartz glass (2) to be detected to a position N +1, and enables N to be N +1, and when N is less than or equal to N, the step returns to the step 3), and when N is greater than N, the step goes to the step ;

6) and the computer (9) outputs the coordinates of all the low-threshold defects, namely the measurement and the coordinate positioning of the large-caliber fused quartz glass low-threshold defects are realized in the full-caliber range, and the measurement is finished.

Technical Field

The invention relates to the field of measurement of defects of optical elements, in particular to a device and a method for measuring low damage threshold defects of large-caliber fused quartz glass.

Background

The large-caliber fused quartz optical glass is an important base stone of optical components in a strong laser device, and the processing quality of the surface and the sub-surface of the large-caliber fused quartz optical glass directly influences and determines the comprehensive performance indexes (such as peak power, beam quality and the like) of a strong laser system. At present, various types of defects are generated on the surface and the subsurface of fused quartz glass by mainstream fused quartz processing technology, wherein the low damage threshold defect can cause fatal damage to optical components in a strong laser device, so that the improvement of various performances of a strong laser system is seriously restricted, and therefore, the accurate measurement of the low threshold defect on the large-caliber fused quartz processing surface has very important significance.

The conventional common method for detecting the low-threshold defect on the processing surface of the small-caliber fused quartz glass is a photo-thermal weak absorption measurement method, but because the area of a single measurement region of the method is too small (10 multiplied by 10 mu m), for the large-caliber fused quartz glass (such as 400 multiplied by 400mm), if the measurement mode of two-dimensional point-by-point scanning is adopted, the photo-thermal weak absorption measurement method needs about 50000 hours to complete the measurement of the low-threshold defect in the full caliber of the large-caliber fused quartz glass, which is obviously not practical.

Disclosure of Invention

In order to solve the defect that the speed of measuring the low-threshold defect by the existing method is very low, the invention provides measuring devices and measuring methods for the low-threshold defect of the large-caliber fused quartz element, and the measuring devices can improve the measuring speed of the existing low-threshold defect by tens of thousands of times.

The technical solution of the invention is as follows:

A device for measuring the low threshold defect of large-caliber fused quartz glass is characterized by comprising a two-dimensional mechanical scanning mechanism, a laser source, a light filter, a spectrometer, a stepping motor controller, a data collector, a laser controller and a computer, wherein the two-dimensional mechanical scanning mechanism is used for placing the large-caliber fused quartz glass to be measured, laser emitted by the laser source irradiates on the surface of the large-caliber fused quartz glass to be measured, the light filter and the spectrometer are sequentially arranged in the direction of fluorescence emitted by the surface defect of the large-caliber fused quartz glass to be measured, the output end of the spectrometer is connected with the input end of the computer, and the output end of the computer is respectively connected with the control end of the two-dimensional mechanical scanning mechanism through the stepping motor controller and is connected with the control end of the laser source through the laser controller.

The laser is used for providing an excitation light source for the measuring system, the spectrometer is used for detecting a fluorescence spectrum of a low-threshold defect (through early experimental research, the fact that almost all low-threshold defects have fluorescence peaks at specific wavelength positions on the surface of fused quartz glass is found, therefore, whether the low-threshold defects exist on the surface of a fused quartz sample can be judged in reverse through measuring the fluorescence spectrum), the optical filter is used for filtering out environment stray light with other wavelengths, the two-dimensional scanning mechanism is used for scanning large-caliber fused quartz glass to be measured in two dimensions, the stepping motor controller is used for controlling mechanical movement of the two-dimensional scanning mechanism, the laser controller is used for controlling the laser, the data collector is used for collecting electric signals output by the detector, and the computer is used for achieving automatic measurement and control functions such as hardware control, data collection and data storage.

The method for measuring the large-caliber fused quartz glass low-threshold defect by using the measuring device for the large-caliber fused quartz glass low-threshold defect mainly comprises the following measuring steps:

1) placing the large-caliber fused quartz glass to be detected on the two-dimensional mechanical scanning mechanism, irradiating the surface of the large-caliber fused quartz glass to be detected with laser output by the laser source, and adjusting the spectrometer and the optical filter to align with fluorescence emitted by the surface defect of the large-caliber fused quartz glass to be detected;

2) starting the computer, and under the control of the computer, controlling the two-dimensional mechanical scanning mechanism by the stepping motor controller to move the large-caliber fused quartz glass to be detected to an initial position, wherein laser output by the laser source irradiates the initial position on the surface of the large-caliber fused quartz glass to be detected, N is 1, and the number of positions irradiated by the large-caliber fused quartz glass to be detected by laser scanning is N;

3) under the control of the computer, the laser output by the laser source 3 irradiates on the surface n of the large-caliber fused quartz glass to be detected, and the spectrometer measures the fluorescence spectrum emitted from the surface n of the large-caliber fused quartz glass to be detected and inputs the fluorescence spectrum into the computer;

4) the computer judges whether the position n has a fluorescence spectrum corresponding to the low threshold defect, if so, the computer records the coordinate of the position n, namely the position n has the low threshold defect;

5) the computer controls the two-dimensional mechanical scanning mechanism 1 through the stepping motor controller, moves the large-caliber fused quartz glass to be detected to a position N +1, and enables N to be N +1, when N is not more than N, the step 3 is returned, and when N is more than N, the step is carried out;

6) and the computer outputs the coordinates of all the low-threshold defects, namely the measurement and the coordinate positioning of the large-caliber fused quartz glass low-threshold defects are realized in the full-caliber range, and the measurement is finished.

The invention has the following advantages:

compared with the existing photothermal weak absorption measurement method (the size of a single measurement area is about 10 multiplied by 10 microns), the single measurement area of the invention can reach 5 multiplied by 5mm, so the measurement speed can be improved by tens of thousands of times.

Drawings

FIG. 1 is a schematic view of a measuring apparatus for measuring a low threshold defect in large caliber fused silica glass.

Fig. 2 is a schematic diagram of a laser two-dimensional scanning track.

Detailed Description

The invention is described in detail below with reference to the drawings and examples, but the scope of the invention should not be limited thereto.