Types of light sources used in optical microscopes and what are the characteristics of each?
[Electron microscope
Electron microscope according to the structure and use can be divided into transmission electron microscope, scanning electron microscope, reflection electron microscope and emission electron microscope. Transmission electron microscope is often used to observe those with ordinary microscopes can not distinguish the fine structure of the material; scanning electron microscope is mainly used to observe the morphology of solid surfaces, but also with the X-ray diffractometer or electron spectrometer combined to form the electron microprobe, used for the analysis of the material composition; emission electron microscope for the study of the surface of the self-emission of electrons.
[Optical Microscope
Optical microscope has a variety of classification methods: Chi-Tay can be divided into trinocular, binocular and monocular microscope according to the number of eyepieces used; according to whether the image has a sense of three-dimensional can be divided into stereoscopic vision and non-stereoscopic visual microscope; according to the observation of the image can be divided into biological and metallurgical microscopy, etc.; according to the principle of optics can be divided into polarised, phase contrast and differential interference contrast microscopy, etc.; according to the type of light can be divided into ordinary light, fluorescence, infrared light and laser Microscope, etc.; according to the type of receiver can be divided into visual, photographic and TV microscopes. Commonly used microscopes include binocular continuous zoom stereomicroscope, metallurgical microscope, polarising microscope, ultraviolet fluorescence microscope, etc..
A binocular stereo microscope uses a two-channel optical path to provide a stereoscopic image for the left and right eyes. It is essentially two single-tube microscopes placed side by side, the optical axis of the two tubes constitute the equivalent of people with binocular observation of an object formed by the angle of view, so as to form a stereoscopic visual image of three-dimensional space. Binocular stereomicroscope is widely used in biological and medical fields for section operation and microsurgery; in industry, it is used for observation, assembly and inspection of tiny parts and integrated circuits.
Metallographic microscope is specially used to observe the metallographic organisation of opaque objects such as metals and minerals. These opaque objects can not be observed in the ordinary transmitted light microscope, so the main difference between metallographic and ordinary microscopes is that the former to reflected light, while the latter to transmitted light illumination. In metallographic microscopy, the illumination beam is directed from the direction of the objective lens to the surface of the object being observed, and is reflected by the object surface and then returned to the objective lens for imaging. This type of reflected illumination is also widely used in the inspection of integrated circuit wafers.
Ultraviolet fluorescence microscope is a microscope that uses ultraviolet light to stimulate fluorescence for observation. Some specimens cannot be perceived in visible light, but after staining, they can emit visible light due to fluorescence when irradiated with ultraviolet light, forming a visible image. These microscopes are commonly used in biology and medicine.
Television microscopes and charge-coupled microscopes are microscopes that use a television camera target or a charge-coupled device as the receiving element. In the real image surface of the microscope into the TV camera target or charge coupler instead of the human eye as a receiver, through these optoelectronic devices to convert the optical image into an electrical signal image, and then the size of the detection, particle counting and other work. This type of microscope can be used in conjunction with a computer, which facilitates the automation of detection and information processing, more often used in the need to carry out a large number of tedious detection work occasions.
Scanning microscope is the imaging beam can be relative to the object surface for scanning motion of the microscope. In the scanning microscope rely on narrowing the field of view to ensure that the objective lens to achieve the highest resolution, while using optical or mechanical scanning methods, so that the imaging beam relative to the object surface in a larger field of view for scanning, and information processing technology to obtain a synthetic image of a large area of information. This type of microscope is suitable for the observation of large field of view images that require high resolution. Coarse focusing helix: wide range of up and down mobilisation of the lens barrel.
