Optical Glass Classification And Application Areas
Can change the direction of light propagation, and can change the UV, visible or infrared light relative to the spectral distribution of the glass. The optical glass in the narrow sense refers to colorless optical glass. The generalized optical glass also includes colored optical glass, laser glass, quartz optical glass, anti-radiation glass, ultraviolet infrared optical glass, fiber optical glass, sound glass, magneto-optical glass and light discoloration glass. Optical glass can be used in the manufacture of optical instruments in the lens, prism, mirrors and windows. Components made of optical glass are key components in optical instruments.
Optical glass is the basis and important component of optoelectronic technology industry. Especially in the 20th century, 90 years later, with the optical and electronic information science, the continuous integration of new materials science, as optoelectronic basic materials, optical glass in optical transmission, optical storage and photoelectric display three areas of application is by leaps and bounds, become Social information, especially the development of optoelectronic information technology, one of the basic conditions.
With the sustained and stable development of the domestic economy, China's optical glass manufacturing industry is developing rapidly. According to the National Bureau of Statistics data show that in 2010, the optical glass manufacturing industry, the number of enterprises above designated size of 246, the industry annual sales income of 3.455 billion yuan, an increase of 53.70%; profits of 1.537 billion yuan, up 87.10% Scale reached 26.45 billion yuan, an increase of 77.49%. As the optical glass manufacturing industry to domestic sales, the financial crisis on its relatively small, the industry is still showing a better growth momentum.
2, brief introduction
A glass material for the manufacture of lenses, prisms, mirrors, windows, etc. of optical instruments or mechanical systems. Including colorless optical glass (usually referred to as optical glass), colored optical glass, radiation resistant optical glass, radiation glass and optical quartz glass. Optical glass has a high degree of transparency, chemical and physical (structure and performance) on the high degree of uniformity, with specific and accurate optical constants. It can be divided into silicate, borate, phosphate, fluoride and sulfur compounds series. The variety is mainly classified according to their position in the refractive index (nD) - Abbe number (VD). Traditionally, various types of glass with nD> 1.60, VD> 50 and nD <1.60, VD> 55 are designated as coronal (K) glass, and the rest of the glass is defined as flint (F) glass. Coronal glass is generally convex lens, flint glass for concave lens. Usually coronal glass belongs to the alkali borosilicate system, the lightly corona glass belongs to the aluminosilicate system, the corona glass and the barium flint glass belong to the alkali-free borosilicate system, and most of the flint glass belongs to lead potassium silicate system. With the continuous expansion of the field of application of optical glass, its variety is constantly expanding its composition, including almost all the elements in the periodic table.
An inorganic glassy material that transmits light by refraction, reflection, transmission, or by absorbing the intensity or spectral distribution of light. Has a stable optical properties and a high degree of optical uniformity.
3, optical glass classification
Colorless optical glass
The optical constant has a specific requirement, with a high visible area, no choice to absorb coloring and so on. According to the size of the Abbe number is divided into the crown and flint glass, all kinds of high and low according to the refractive index is divided into several kinds, according to the size of the order of refraction. Used as a telescope, microscope, camera and other lenses, prisms, mirrors and so on.
Anti - radiation optical glass
There is a high absorption capacity for high energy radiation, with high lead glass and CaO-B2O2 system glass, which can prevent gamma rays and X-ray irradiation, which absorbs slow neutrons and thermal neutrons, mainly for nuclear industry , Medical field as a mask and peep window material.
Radiation - resistant optical glass
In some γ-ray, X-ray irradiation, the visible area permeability changes less, varieties and grades and colorless optical glass, for the manufacture of high-energy irradiation under the optical instruments and peep window.
Colored optical glass
Also known as filter glass. For the UV, visible, infrared specific wavelength selective absorption and permeability, according to the spectral characteristics are divided into selective absorption, cut-off and neutral gray 3; according to the coloring mechanism is divided into ion coloring, metal colloid coloring and sulfur selenium Chemical coloring class 3, mainly used in the manufacture of filters.
UV and IR optical glass
In the ultraviolet or infrared band has a specific optical constant and high transmittance, used as UV, infrared optical instruments or as window material.
Optical quartz glass
With silica as the main component, with high temperature, low expansion coefficient, high mechanical strength, good chemical properties, for the manufacture of various bands through the special requirements of the prism, lens, window and mirror. In addition, there are for the large-scale integrated circuit manufacturing photomask board, liquid crystal display panel, video disc plate plate glass; light along the magnetic field lines through the glass when the polarization plane rotation of the magneto-optic glass; light in a certain direction by transmission Ultrasonic glass, the occurrence of light diffraction, reflection, convergence or optical frequency shift of sound and light glass.
4, dispersion classification
According to the dispersion is divided into two categories: smaller dispersion for the crown (K), the larger dispersion for the flint (F).
① Coronal optical glass is divided into fluoro (FK), light crown (QK), phosphorus crown (PK), heavy phosphorus crown (ZPK), crown (K), re-crown (ZK), barium (BaK) Crown (LaK), titanium crown (TiK) and special crown (TK) and so on.
The flint optical glass is divided into light flint (QF), flint (F), heavy flint (ZF), barium flint (BaF), heavy barium flint (ZBaF), lanthanum flint (LaF), heavy lanthanum flint (ZLaF) Titanium flint (TiF), coronite (KF) and special flint (TF). They are distributed in different areas in the relationship between the refractive index nd and the dispersion coefficient v (see figure).
Anti-radiation glass is a kind of generalized optical glass. Including radiation protection glass and radiation resistant glass.
① radiation glass is mainly on the γ-ray and X-ray have a greater absorption capacity of the glass. When γ-rays or X-rays enter the protective glass, the positive and negative electron pairs are generated due to the photoelectric effect inside the glass, and both the excited state and the free state electrons are generated, and the incident γ-ray or X-ray energy is reduced and the penetrating power is decreased , Played a protective role. When the density of radiation-proof glass increases, the shielding capacity is also increased accordingly. The gamma-resistant glass has a density of not less than 4.5 g / cm. In recent years, glass having a density of 6.2 to 6.5 g / cm has been started, and ZF series is commonly used.
② radiation-resistant optical glass mainly refers to the role of γ-ray is not easy to color the optical glass. The name of the Radiation-Resistant Optical Glass Grade is still based on the optical glass grade, indicating the radiant number of radiant, for example, the optical constant of the K509 radiation-resistant optical glass is the same as K9 and is capable of γ-ray. Ordinary glass is irradiated by high-energy radiation to produce free electrons, which combine with the absence of the interior of the glass to form a color center. But also can make the nucleus shift, destruction of the normal structure, but also produce color center, so that the glass coloring.
In the radiation-resistant optical glass, CeO2 is introduced. After irradiation with high-energy γ-rays, electrons can be trapped by the formula, and the color center of the glass is not generated, and the absorption band of Ce and Ce is in the ultraviolet region. When the CeO2 content is too high, in the ultraviolet, infrared absorption band extends to the visible region, so that the blue absorption of visible light increased, resulting in yellow glass. At the same time, will also be due to the impact of other components of the glass and deepen the color, so the content of CeO2 can not be too high, in K509 CeO2 content of about 0.4% to 0.5% in K709 CeO2 is about 1%.
6, the production of raw materials
High quality quartz sand as the main material. Addition of accessories. Because rare earth has high refractive index, low dispersion and good chemical stability, can produce optical glass, used to manufacture high-level cameras, camcorders, telescopes and other advanced optical instruments of the lens. For example, a lanthanum glass with excellent optical properties of lanthanum lao360% boron oxide b2o340% is an indispensable optical material for the lens of the advanced camera and the lens of the periscope. In addition, the use of some rare earth elements of radiation protection properties, can produce radiation glass.
7, cold processing
A chemical vapor phase heat treatment means and monolithic soda lime silica glass to change its original molecular structure without affecting the original color and light transmittance of the glass, to achieve super hardness standards, under the impact of high temperature flame to meet the fire requirements of the super Hardness fireproof glass and its manufacturing method, special equipment. (72% to 83%), argon (7% to 10%), gaseous copper chloride (8% to 12%), nitrogen (2) % ~ 6%). It contains the following process: the use of soda-lime glass as the substrate for cutting, fine grinding edge of the cold → → cold-processed soda-lime glass glass chemical vapor heat treatment → sodium silicate glass surface plating protective film treatment → The soda lime silica glass surface for special physical steel treatment. By the cylinder and its associated with the cylinder head, and the cylinder head connected to the reactor constitute a dedicated thermal decomposition gasification equipment.
Because of the defects in the processing or use of various new varieties of optical glass, it is also aimed at improving the physical and physical and chemical properties of various new varieties of optical glass while studying the field of expanded optical glass. As well as the production process carried out a lot of work.