Judgment requirements for optical glass and optical lens performance requirements

There are many types of glass, one of which is optical glass, which is capable of changing the direction of light propagation. It is widely used in optical instruments such as lenses and prisms. Optical glass is not like ordinary glass, and the requirements for the quality of optical glass are very high. The difference between optical glass and other glass is that it is used as a component of the optical system and must meet the requirements of optical imaging.

Therefore, the determination of the quality of optical glass also includes some special and more stringent indicators. Optical glass has the following requirements:

First, the specific optical constants and the consistency of the optical constants of the same batch of glass

Each variety of optical glass has a standard refractive index value for different wavelengths of light, as the basis for optical designers to design optical systems. So the factory production of optical glass optical laser focusing mirror constants must be within a certain tolerance range of these values, otherwise the actual image quality and the design of the expected results do not match and affect the quality of optical instruments.

At the same time, as the same batch of instruments often use the same batch of optical glass manufacturing, in order to facilitate the unified correction of the instrument, the same batch of glass refractive index tolerance than their deviation from the standard value of more stringent.

Second, a high degree of transparency

Optical system into the image of the brightness and glass transparency is proportional. The transparency of optical glass for a wavelength of light is expressed in terms of the light absorption coefficient Kλ. Light through a series of prisms and lenses, its energy is partly lost in the optical parts of the interface reflection and the other part of the medium (glass) itself absorbed. The former increases with the refractive index of the glass, the high refractive index of the glass this value of laser protection mirror is very large, such as for heavy flint glass a surface light reflection loss of about 6%.

Therefore, for optical systems containing multiple thin lenses, the main way to improve the transmission rate is to reduce the reflection loss of the lens surface, such as the coating of the surface of the transmissive film layer. For large-sized optical parts such as the objective lens of astronomical telescope, the transmission rate of the optical system is mainly determined by the light absorption coefficient of the glass itself due to its thickness. By improving the purity of the glass raw material and preventing any coloring impurities from mixing in the whole process from ingredients to melting, it is generally possible to make the light absorption coefficient of glass less than 0.01 (i.e., the light transmission rate of glass with a thickness of 1 cm is greater than 99%).

Optical lenses used to use spherical design, so that the aberration and deformation increased, the result of the obvious image unclear, the visual field crooked laser collimator curved, narrow field of view and other undesirable phenomena, corrected the image, solve the problem of visual field distortion, etc., at the same time, so that optical lenses are lighter, thinner, flatter, and, optical lenses still maintain excellent impact resistance, so that the wearer safe to use, optical lenses around to see objects with distortion In the era of continuous technological progress, the aspheric design, an optical miracle, reduces the optical lens edge aberration to the bottom, making it possible to meet the needs of customers with a wide field of vision.

Optical lenses have a flatter base bend, lighter weight, look more natural, beautiful, in the case of high diopter, can reduce the deformation of the eye, optical lenses for consumers with high vision, optical lenses choose aspheric optical lenses may be more appropriate, wear aspheric optical lenses almost do not feel the presence of its optical lenses, it is for your eyes to lose weight, enjoy the ease it brings you at will, and The outer surface of the optical lens reflects the daylight tube like a barrel shape with bulging in the middle and gradually narrowing on both sides; the higher the luminosity of the optical lens the more obvious the optical lens is.

Measure the trend of diopter change from the optical center to the edge of the optical lens, optical lens will be placed laterally aspheric optical lens under the fluorescent light source transmitted light, choose the best base bend and other methods, optical lens to control the aberration in a small range, modern eye optical lens has adopted computer design, through the computer can make a very accurate optical path tracing, find out the best form of optical lens, you can find the optical lens The higher the luminosity, the more obvious this effect is, and the test is applicable to both myopic and presbyopic lenses of higher luminosity.