The filter is made of plastic or glass and added with special dyes. The transmittance of the glass sheet is originally similar to that of air, and all colored light can pass through, so it is transparent, but after dyeing the dye, the molecular structure changes and the refractive index also changes, which changes the passage of certain colored light. For example, a beam of white light passes through a blue filter and emits a beam of blue light, while green light and red light are very few, and most of them are absorbed by the filter.

　　 filter is used to attenuate (absorb) certain light wavebands in light waves or pass light waves in a small range of precise selection, while reflecting (or absorbing) other undesirable light waves. Hope to pass the band. By changing the structure of the filter and the optical parameters of the film, various spectral characteristics can be obtained, so that the filter can be controlled, adjusted and the optical lens can change the transmission, reflection, polarization or phase state of the light wave.

　　All optical components are precision instruments, especially optical filters, and the surface is easily scratched. Improper cleaning and storage methods may damage the surface film of the filter, reduce its application performance and shorten its service life. Therefore, the correct maintenance method is extremely important. Let's take a look at the small details that should be paid attention to in the ordinary use of optical filters:

　　1. Take care as much as possible in the usual use. At the same time, pay attention to the external environment to avoid scratches on the filter by clothes zippers, buttons, etc., or place the filter in a dirty or dusty environment.

　　2. Wear finger cots when touching the filter to avoid salt and acid substances on your hands from corroding the surface of the substrate.

　　3. When taking the filter, hold the edge of the filter in your hand, even if you are wearing a finger cot, do not touch the light-transmitting surface of the filter .

　　4. The filter should be placed on a soft and clean object, not on glass, metal, table, or dirty paper.

　　 5. When storing, it should be placed in clean capacitor paper or special lens cleaning paper. The best storage temperature is about 23℃, and the humidity is not higher than 40%. It is better to put in a dry storage cabinet.

　　 6. Do not stack the filters together to avoid wear.

　　 7. If there are stains or fingerprints on the surface, you can wipe it with absolute ethanol or similar functional solvents. The specific method is as follows: wear a dust-free finger laser lens cover on your finger, soak the towel with absolute ethanol, drag the edge of the towel soaked with ethanol, and move it in a single direction on the surface of the filter. The wiping action should be as hard and light as possible.

　　 Optical glass can change the propagation direction of light and can change the relative spectral distribution of ultraviolet, visible or infrared light. Optical lens materials are mainly composed of oxides, such as: silicon dioxide, boron trioxide, phosphorus pentoxide, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, zinc oxide, aluminum oxide, etc. After these raw materials are melted at high temperature, they are cooled and condensed into a uniform, transparent, brittle and amorphous substance.

　　Generally, optical lenses are classified and graded according to the following quality indicators:

　　1, refractive index, dispersion coefficient and The allowable difference of the standard value is the value of the high power laser lens group.

　　2, the consistency of refractive index and dispersion coefficient in the same batch of glass.

　　3. Optical uniformity.

　　4. Stress birefringence.

　　5. Stripe degree.

　　6. Bubble degree.

　　7. Radiation resistance (N series glass).

　　 8. Light absorption coefficient.

　　 According to the above classification criteria, optical lenses can be divided into many types. Then we have to choose suitable products according to actual production needs.

　　Optical filter is an optical device used to select the required radiation band. Optical filters are made by adding special dyes to plastic or glass substrates or evaporating optical films on their surfaces to attenuate (absorb) certain light bands in light waves or to precisely select light waves in a small range to pass through the mirror. , While reflecting (or absorbing) other undesired bands. By changing the structure of the filter and the optical parameters of the film, various spectral characteristics can be obtained, so that the optical filter can control, adjust and change the transmission, reflection, polarization or phase state of the light wave.

　　Insulation glass can generally be divided into two categories according to different requirements. One type is that the glass can absorb a large amount of infrared light, and the glass is basically colorless, that is, this kind of glass should be within the range of 400m to 76 in the visible light region. Also Linnei has a high smooth transmission curve. In terms of composition, this kind of glass generally belongs to the phosphate glass system. The other type is that it is required to absorb some infrared rays, and the glass is also allowed to have some colors. This kind of insulation glass generally belongs to the silicate glass system