Why is a confocal microscope needed?
The optical microscope has been perfected through the efforts and improvements of our great predecessors. In fact, conventional microscopes can provide us with beautiful microscopic images simply and quickly. However, an event that brought revolutionary innovation to this almost perfect world of microscopes occurred, which was the invention of the "laser scanning confocal microscope". The characteristic of this new type of microscope is the use of an optical system that extracts only the image information on the surface where the focus is concentrated. By changing the focus and restoring the obtained information in the image memory, a vivid image with complete 3D information can be obtained. Through this method, information about surface shape that cannot be confirmed by conventional microscopes can be easily obtained. In addition, for typical optical microscopes, "improving resolution" and "deepening focal depth" are contradictory conditions, especially at high magnification. However, for confocal microscopes, this problem is easily solved.
Advantages of confocal optical systems
The confocal optical system provides point illumination to the sample, while the reflected light is also received by a point sensor. When the sample is placed at the focal position, almost all of the reflected light can reach the photoreceptor. When the sample deviates from the focal point, the reflected light cannot reach the photoreceptor. That is to say, in a confocal optical system, only the image that coincides with the focal point will be output, and the spot and useless scattered light will be blocked.
Why use laser?
In a confocal optical system, point illumination is applied to the sample, and the reflected light is also received by a point sensor. Therefore, point light sources become necessary. Laser is a very point light source. In most cases, the light source of confocal microscopy is a laser light source. In addition, the monochromaticity, directionality, and excellent beam shape of lasers are also important reasons for their widespread adoption.
