Method for detecting washed surface of optical substrate used for laser thin film element

Abstract

The invention relates to a method for detecting the washed surface of an optical substrate used for a laser thin film element, belonging to the technical field of optics. A detection procedure process comprises the following steps of: calibrating the visibility of a white light surface detection lamp by using man-made silicon oxide globules of 5 microns and 10 microns in size; carrying out scale contrast on residual grains after the substrate is washed by using silicon oxide globules of 5 microns to 50 microns in size; counting the scale and the number of the residual grains, so as to realize the semi-quantitative detection on micrometer-scale grains on the surface of the substrate with the naked eye; scanning the surface of the substrate by using a weak absorption instrument; counting the number of points of which the absorption is larger than 20ppm and less than 100ppm and the absorption value is larger than 100ppm on the surface of the substrate, thereby realizing the precise evaluation on the washing and elimination efficiency of nano-scale metal oxide powder grains on the surface of the substrate; and measuring the depth and the surface roughness of the scratch on the surface of the substrate by using an atomic force microscope, measuring and recording the number of pocking marks of which the diameters are larger than 20nm, so as to realize the quantitative evaluation on the defects on the surface of the substrate. The method has the advantages that the quantitative detection on the washed surface of the optical substrate is realized, data support is provided for the improvement of the substrate washing process, and the requirements on laser damage after the substrate is plated with films are met.

Description

technical field [0001] The invention relates to a method for detecting the surface of an optical substrate after cleaning, in particular to a method for detecting the surface of a laser thin film after cleaning the optical substrate. Background technique [0002] Laser thin films are key components in high-power laser systems and one of the key factors to achieve the optical performance of the system. Thin film is the most vulnerable link in the laser system. Film damage not only reduces the output quality of the laser, but also easily causes damage to other optical components in the system, thus bringing catastrophic damage to the entire optical system. There are many factors that affect the damage threshold of the thin film, from the processing and cleaning of the substrate, to the design and preparation of the film system, and the subsequent laser pretreatment. As the first step in the preparation of high-power laser thin films, substrate cleaning will directly determine...

AI Technical Summary

Problems solved by technology

At present, for micron-scale particles, the commonly used detection method is to use a 100W white light surface detection lamp to inspect, but this method cannot quantify the particle size, and the accuracy of the inspection depends on the brightness of the bulb, and the brightness of the bulb is affected by the actual use. There are many external factors, such as the start-up time, the total use time of the bulb, etc. Therefore, in order to ensure the accuracy and consistency of the inspection during use, it is necessary to have a method for calibrating the surface inspection lamp

In addition, there are metal oxide particles with a size of tens of nanometers on the surface of the substrate. Although these particles cannot be seen under the surface inspection lamp due to their small size, they can easily cause damage to the substrate under laser irradiation. Contaminants like this on the surface still lack effective detection

In addition to the above-mentioned substrate contamination, the cleaning process will cause a certain degree of damage to the substrate, resulting in surface scratches and pitting. These surface defects also affect the damage threshold of the component, so we also need to effectively detect the defects on the substrate surface. and accurate detection and characterization methods

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