Confocal microscope: It is an optical imaging method that uses point by point illumination and spatial pinhole modulation to remove scattered light from the non focal plane of the sample. Compared with traditional imaging methods, it can improve optical resolution and visual contrast. The detection light emitted from a point light source is focused onto the observed object through a lens. If the object is precisely at the focal point, the reflected light should converge back to the light source through the original lens, which is called confocal, abbreviated as confocal. Confocal microscopy adds a dichroic mirror to the reflected light path, which deflects the reflected light that has already passed through the lens in other directions. There is a pinhole at its focal point, which is located at the focal point. Behind the baffle is a photomultiplier tube (PMT). It can be imagined that the reflected light before and after the detection light focal point cannot be focused on the pinhole through this confocal system and will be blocked by the baffle. So the photometer measures the reflected light intensity at the focal point. Its significance is that a semi transparent object can be scanned in three dimensions through a moving lens system. This idea was proposed by American scholar Marvin Minsky in 1953, and it took 30 years of development before using laser as the light source to develop a confocal microscope that met Marvin Minsky's ideal.

An optical microscope is a type of microscope that uses optical lenses to produce image magnification effects. The light incident from an object is magnified by at least two optical systems (objective lens and eyepiece). Firstly, the objective lens produces an enlarged real image, which is observed by the human eye through an eyepiece that acts as a magnifying glass. A typical optical microscope has multiple interchangeable objectives, allowing the observer to change the magnification as needed. These objectives are usually placed on a rotatable objective disc, which allows different eyepieces to easily enter the optical path by rotating the objective disc. Physicists discovered the law between magnification and resolution, and people realized that the resolution of optical microscopes has a limit. This limit of resolution restricts the infinite increase of magnification, with 1600 times becoming the highest limit of magnification for optical microscopes, which greatly limits the application of morphology in many fields.

The resolution of an optical microscope is limited by the wavelength of light, generally not exceeding 0.3 micrometers. If a microscope uses ultraviolet light as a light source or objects placed in oil, the resolution can be further improved. This platform has become the foundation for building other optical microscopy systems.