The raw materials for the production of optical glass are some oxide, hydroxide, nitrate and carbonate, and the introduction of phosphate or fluoride in accordance with the requirements of the formula. In order to ensure the transparency of the glass, we must strictly control the content of colored impurities, such as iron, chromium, copper, manganese, cobalt, nickel and so on. Accurate weighing, uniform mixing. The main production processes are melting, forming, annealing and inspection.

1, smelting

Continuous smelting process with single crucible batch melting method and tank furnace (see kiln). A single crucible melting method can be divided into clay crucible melting method and platinum crucible melting method. No matter what kind of smelting method is used, it is necessary to use a blender to mix, and the temperature and the stirring are controlled strictly, so that the optical glass liquid can reach a high degree of uniformity.

2, molding

Optical glass molding method of classical broken crucible method, rolling method and casting method. But now, more and more widely by leaking molding (using a single crucible or outflow continuous melting liquid), can directly pull rod or dropping pressure type or leakage material forming the large size of the blank, improve material drop efficiency of yield and usage.

3, annealing

In order to eliminate the internal stress of the glass and improve the uniformity of the optical system, a strict annealing system must be made.

4, inspection

The indexes include: optical constants, optical uniformity, stress birefringence, stripes, bubbles, etc..

Optical glass for a long time use do not use shall be placed in dry and ventilated place, ban placed in damp places, it is best placed in the cabinet moisture custody, prevent "frosted" appears on the surface.

First: cutting, leveling

Optical glass materials for the lump material, needs to feed into a lump of material, and the appearance of leveling, preparing for the first step.

Second way: cutting

The leveling good glass slice

Third: chamfer edge

According to customer requirements chamfering chamfering, trimming.

Fourth way: fine grinding, double side polishing

The semi finished machine on the fine grinding, double-sided polishing, is a double-sided smooth to achieve the customer's finish requirements.

Fifth way: inspection, packaging

Finished out, after the inspection, the qualified products inspection package, storage. The final package sent by express.

Optical glass used in the manufacture of lenses, mirrors, mirrors, windows and other glass materials for optical instruments or mechanical systems. Including colorless optical glass (usually referred to as optical glass), colored optical glass, radiation resistant optical glass, radiation proof glass and optical quartz glass, etc.. Optical glass has a high degree of transparency, chemical and physical properties (structure and properties), with a high degree of uniformity, with a specific and accurate optical constants.

The difference between optical glass and other glass is that it is a part of the optical system and must satisfy the requirements of optical imaging. Therefore, the determination of the quality of optical glass also includes some special and more stringent indicators.

Optical lens is in optical glass made lenses, generally refers to through regulation of visible light lenses, optical lenses must be passing through an optical measuring instruments, the purity test, transparency, uniformity, refractive index and dispersion rate is in compliance with specifications, qualified glass block after forging heating, optical lens blanks. After the optical lens is fine grinding, the surface still has a thick layer of cracks. The method to eliminate the crack layer is polishing.

1, colorless optical glass. The optical constants have specific requirements, with the visible area of high transmittance, no choice of absorption and color characteristics. Abbe number size according to the crown and flint glass, all kings and according to the refraction rate level is divided into several kinds and according to the refraction rate size are arranged in order. Used as a telescope, microscope, camera, lens, prism, mirror, etc..

2, anti radiation optical glass. Larger absorption capacity, high lead glass and CaO-B2O2 system glass on high energy irradiation, the former can prevent the gamma ray and X-ray radiation, which can be slow neutron and thermal neutron absorption, mainly used as the shielding and peeped through the window materials in nuclear industry, medical field, and so on.

3, colored optical glass. Filter glass. Ultraviolet, visible and infrared region specific wavelength selective absorption and permeation, according to the spectral characteristics of points for selective absorption, cut-off and neutral grey 3 class; according to the coloring mechanism are divided into 3 types of coloring ion, metal colloid coloring and selenium and sulfur compounds coloring, mainly for manufacturing filter.

4, optical quartz glass. Using silica as the main ingredient, with characteristics of high temperature resistance, thermal expansion coefficient is low, high mechanical strength, chemical properties good for manufacturing of various bands through the special requirements of the prism, lens, window, mirror, etc..

5, ultraviolet and infrared optical glass. In the ultraviolet or infrared wave band with a specific optical constant and high transmittance, used as ultraviolet, infrared optical instrument or as a window material.

6, radiation resistant optical glass. Under a certain gamma ray and X ray irradiation, the visible area transmission rate is less, and the variety and grade are the same as the colorless optical glass, which is used for the manufacture of optical instruments and peep window under high energy irradiation.

Neutral gray mirror, also known as the gray density mirror, referred to as ND mirror, is a piece of gray, pure and transparent advanced optical glass. Its role is by weakening through the lens to reduce light exposure. This filter action is a non selective. That is to say, ND filter of different wavelengths of light for their ability to reduce is equal, uniform, weaken the light only played the role of, and color of the original object does not produced any effect, so it can be true representation of scene contrast and color photography and black and white photography apply equally. According to the "block" of light intensity, neutral gray mirror has multiple densities are available, such as ND2, ND4, nd8 (respectively on the extension of a file, file 2 and 3 file shutter speed) can also be more neutral gray mirror used in combination. It is not difficult to see that the figure behind the ND, that represents the ability to block the ND mirror light. The larger the value of ND, the more serious partial color, the general quality of products are using other techniques for wavelength, as far as possible to minimize the distortion of color and the most faithful to restore.

ND mirror only reduces the intensity of light, so it does not affect the final image of the color, it will not affect the camera's white balance and automatic exposure. Use the ND mirror, will not be subject to the color and contrast of the object to produce any effect. In addition, since the SLR is carried out by the lens of the camera, so the ND lens will not have any impact on the camera's automatic exposure system.

In short, the need for people to use a slow shutter, or reduce the case of external light, ND mirror is very useful additional lenses. Of course, due to different lens aperture is different, so the ND mirror also has different caliber, in the use of the lens according to the caliber of the choice of different diameter ND mirror.

Infrared wavelength and visual quality of simple lenses:

A:720nm or 680nm, 665650nm, or the following, cloudy or facing the common brightness of the TV can see the red light.

B:760nm, in front of a 40 Watt household light bulb can see the light bulbs in the near segment of the very light goods. Facing the 20 Watt energy-saving lamps can be found very dark and light tubes.

C:850nm against 40 Watt household lighting can see filament lamp. In front of a 20 Watt energy-saving lamp is almost can not see anything to, if you can see a lamp for secondary leaky lens.

D:950nm almost invisible to the 40 Watt light bulbs.