The Treatment for Coating Thickness Gauge Probe Sensitivity Decline
1. After the efforts and improvements of our great predecessors, the optical microscope has reached the point of perfection. In fact, ordinary microscopes can provide us with beautiful microscopic images simply and quickly. However, an event that brought revolutionary innovation to this nearly perfect microscope world happened, which is the invention of the "laser scanning confocal microscope". The feature of this new type of microscope is that it adopts an optical system that only extracts image information on the surface where the focus is concentrated, and restores the obtained information in the image memory while changing the focus, so that complete 3D information can be obtained. A stark image of intelligence. With this method, it is possible to easily obtain information about the surface shape that cannot be confirmed with a normal microscope. In addition, for ordinary optical microscopes, "increasing resolution" and "deepening depth of focus" are contradictory conditions, especially at high magnifications, this contradiction is more prominent, but in terms of confocal microscopes, this problem is easily solved.
2. Advantages of confocal optical system
Schematic diagram of laser confocal microscope
The confocal optical system performs point illumination on the sample, and the reflected light is also received by the point receptor. When the sample is placed in the focus position, almost all the reflected light can reach the photoreceptor, and when the sample is out of focus, the reflected light cannot reach the photoreceptor. That is to say, in the confocal optical system, only the image that coincides with the focal point will be output, and the light spots and useless scattered light will be shielded.
3. Why use laser?
In the confocal optical system, the sample is illuminated at a point, and the reflected light is also received by a point photoreceptor. Therefore, a point light source becomes necessary. Lasers are very point light sources. In most cases, laser light sources are used as light sources for confocal microscopes. In addition, the characteristics of monochromaticity, directionality and excellent beam shape of laser are also important reasons for its wide adoption.
