Several classifications of optical microscopes
1. Binocular stereomicroscope
A binocular stereo microscope, also known as a "solid microscope" or "dissecting microscope," is a visual instrument with a sense of stereopsis. Widely used in the fields of biology and medicine for slicing operations and microsurgery; Used in industry for observation, assembly, inspection, and other work of small parts and integrated circuits.
At present, the optical structure of a stereo microscope is composed of a shared primary objective, which separates the two beams of light imaged by two sets of intermediate objective lenses - zoom lenses - and forms a unified viewing angle before being imaged by their respective eyepieces. Its magnification change is obtained by changing the distance between the intermediate lens groups, so it is also known as a "Zoom stereo microscope". With the requirements of applications, currently stereo lenses can be equipped with a variety of optional accessories, such as fluorescence, photography, photography, cold light sources, and so on.
2. Metallographic microscope
Metallographic microscope is a specialized microscope used to observe the metallographic structure of opaque objects such as metals and minerals. These opaque objects cannot be observed in ordinary transmission light microscopes, so the main difference between metallographic and ordinary microscopes is that the former uses reflected light, while the latter uses transmitted light for illumination. In a metallographic microscope, the illumination beam is directed from the objective lens to the surface of the observed object, reflected by the surface, and then returned to the objective lens for imaging. This reflective lighting method is also widely used in the detection of integrated circuit silicon wafers.
3. Polarizing microscope
Polarization microscope is a type of microscope used to study so-called transparent and opaque anisotropic materials. Any substance with birefringence can be clearly distinguished under a polarizing microscope. Of course, these substances can also be observed using staining methods, but some are impossible and must be observed using a polarizing microscope.
4. Fluorescence microscope
A fluorescence microscope is a device that uses short wavelength light to irradiate an object that has been stained with fluorescein, excite it, and produce fluorescence of a growing wavelength for observation. Fluorescence microscopy is widely used in fields such as biology and medicine.
5. Phase contrast microscope
In the development of optical microscopes, the successful invention of phase contrast microscopy is an important achievement in modern microscopy technology. We know that the human eye can only distinguish between the wavelength (color) and amplitude (brightness) of light waves. For colorless and bright biological specimens, when light passes through, the wavelength and amplitude do not change much, making it difficult to observe the specimen in the bright field.
A phase contrast microscope uses the difference in optical path of the object being examined for microscopic examination, which effectively utilizes the interference phenomenon of light to transform the phase difference that cannot be distinguished by the human eye into a distinguishable amplitude difference. Even colorless and transparent substances can become clear and visible. This greatly facilitates the observation of living cells, so phase contrast microscopy is widely used in inverted microscopes.
6. Differential interference contrast microscope (DIC)
Differential interference contrast microscopy emerged in the 1960s. It not only allows for the observation of colorless and transparent objects, but also presents a strong three-dimensional relief in the image, and has certain advantages that contrast microscopy cannot achieve, making the observation effect more realistic.
7. Digital microscope
A digital microscope is a microscope that uses a camera (i.e. a television camera target or charge coupled device) as the receiving element. Install a camera at the real image surface of the microscope instead of the human eye as the receiver, convert optical images into electrical signal images through this photoelectric device, and then perform size detection, particle counting, and other work on them. This type of microscope can be combined with computers, which facilitates the automation of detection and information processing, and is often used in situations where a large amount of tedious testing work is required.
