Flag of optical glass, optical glass is just a number, optical glass machining process: the raw materials into a different pot (known as the crucible) to do such as cooking pot and then heated to 1500 degrees, to melt into water samples of raw materials , then cooling, poured into the mold, cooling, become optical glass, then the corresponding production of each pot by the glass, there a number that is Guo number, his purpose is because the glass in each pot, which the technical parameters There will always be some minor differences, you can select the corresponding glass, as glass with the same pot for processing. Do not copy paste, this is the most popular explanation, you should be able to understand the

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  Used in the manufacture of optical instruments or mechanical system lenses, prisms, mirrors, windows and other glass materials. Including the colorless optical glass (usually referred to as optical glass), colored optical glass, radiation-resistant optical glass, radiation quartz glass and optical glass. Optical glass with high transparency, chemical and physics (structure and performance) on a high degree of uniformity, with a specific and accurate optical constants. It can be divided into silicate, borate, phosphate, fluoride and chalcogenide compounds series. Variety, mainly by their refractive index (nD) - Abbe value (VD) to classify the location map. Traditionally, nD> 1.60, VD> 50 and nD <1.60, VD> 55 types of glass as a crown (K) glass, the other types of glass as a flint (F) glass. General for convex crown glass, flint glass for a concave lens. Usually are alkali borosilicate crown glass system, light aluminum silicate crown glass is heavy barium crown glass and flint glass is alkali borosilicate system, most of the flint glass is potassium silicate of lead system. With the application of optical glass Expanding the scope of its species in the continuing expansion of its composition includes almost all the elements of the periodic table.
  By refraction, reflection, light transmission through the means or through the absorption of the laser light intensity or spectral distribution of an inorganic glassy material. With stable optical properties and high optical homogeneity.
  Divided by the optical characteristics:
  ① colorless optical glass. There are specific requirements on the optical constants, has the visible area of high through no choice absorption coloring and so on. Abbe number by size class is divided into crown classes and flint glass, then by all kinds of high and low refractive index is divided into a number of species, arranged according to the order of the refractive index. More as a telescope, microscope, camera lenses, prisms, mirrors and so on.
  ② anti-radiation optical glass. Greater high-energy radiation absorption capacity, high-lead glass and CaO-B2O2 system glass, the former prevents the γ-ray and X-ray irradiation, which can absorb the slow neutrons and thermal neutrons, mainly for nuclear industry , medicine and other materials as shielding and peep window.
  ③ Radiation-resistant optical glass. In some γ, X-ray irradiation, less visible area transmittance change, species and grades the same with the colorless optical glass, high-energy radiation used in the manufacture of optical instruments and peep under the window.
  ④ colored optical glass. Also known as filter glass. The ultraviolet, visible, infrared absorption and specific wavelength of choice through the performance, by selective absorption spectral characteristics into the closing-type and neutral gray three categories; by coloring mechanism is divided into ion coloring, coloring and sulfur colloid metal selenium Category 3 colored compounds, mainly for the manufacture of filter.
  ⑤ ultraviolet and infrared optical glass. In the ultraviolet or infrared optical constants with specific and high transmittance for ultraviolet, infrared, optical instruments or materials used for window.
  ⑥ Optical quartz glass. Silica as the main component, high temperature, low coefficient of expansion, high mechanical strength, chemical properties and good features, used in the manufacture of the special requirements of various bands through the prism, lenses, windows and mirrors and so on. In addition, large scale integrated circuits for optical mask manufacturing, liquid crystal display panels, video optical disk plate glass; light direction of magnetic field through the plane of polarization occurs when the glass optical rotation of the glass; light transmission through a certain direction ultrasonic glass, the place of light diffraction, reflection, pool, or optical frequency shift of sound and light glass.
  The development of optical glass:
  The development of optical glass and optical instrument development are inseparable. Optical system to the new reforms are put forward new requirements of optical glass, thus promoting the development of optical glass, the same, the successful trial of new varieties of glass are often in turn promote the development of optical instruments.
  First been used to produce optical materials, optical components are natural crystals, said to be ancient Yaxiliya crystal lens, and in ancient China is the use of natural tourmaline (Tea lens), and citrine. Archaeologists in Egypt that year three thousand years ago and we (the Warring States era) people have been able to manufacture glass. However, as the glasses and the mirror glass or the beginning of the thirteenth century in Venice. Engels in the "natural dialectics" of this has given high praise, that this was one of the outstanding inventions. As the astronomers and navigation since the development needs of Galileo, Newton, Descartes, also with a glass of the telescope and microscope. From the sixteenth century, glass has become a major manufacturer of optical components of the material.
  To the seventeenth century, achromatic optical system as the central issue of optical instruments. Since then improved glass composition, were introduced in the lead oxide glass, Hull was in 1729 won the first of the achromatic lens, since then, been divided into the grievances of optical glass and flint glass, two license categories.
  1768 with the South in France, the first method of mixing with the clay bar got a uniform system of optical glass, thus beginning to establish an independent optical glass manufacturing industry. In the mid-nineteenth century, a few developed capitalist countries has established its own optical glass factories, such as France Parala - Mountain Map Company (1872), British Chance Company (1848), the German company Schott (1848 ) and so on.
  Great nineteenth-century development of optical instruments. On the eve of World War I, Germany to the rapid development of military optical instruments, required to break the limits of optical glass that poor. At this time, the famous physicist A joined the Schott factory work. He added a new glass oxides such as BaO, B2O3, ZnO, P2O3, etc., and he studied its optical constants of the glass. On this basis, the development of the injustice barium, boron injustice, injustice and other types of glass, zinc, and also began trial production of a special relative part of the dispersion of flint glass. In this time period, the optical glass that has been greatly expanded, thus arise in optical instruments a more complete camera and microscope objectives.
  Thirties until the twentieth century ago, most of the work is still based on plant Schott. 1934 was a series of heavy reprisal glass, such as Germany and No. SK-16 (620/603) and SK-18 (639/555) and so on. This point, can be considered a stage of development of optical glass.
  Before and after World War II, with a variety of optical devices such as aerial photography, ultraviolet and infrared spectrometer, the development of such advanced camera lens, optical glass, has created new needs. At this time, the corresponding optical glass also has a new development. In 1942, the United States Mo Lai (Morey) and later the Soviet Union and German scientists have successively and scattered rare earth oxides into the glass, which expanded the variety of glass, by a series of high refractive index and low dispersion optical glass, such as Germany LaK, LaF, the Soviet Union and ТЬФ other varieties CTK series. At the same time, also had a large dispersion of low refractive index of glass and received a series of fluorine titanium silicate glass optical system, such as the Soviet Union ЛФ-9, ЛФ-12, German F-16 and other varieties.
  Because of new varieties of optical glass in the processing or use of performance more or less flawed, so the field of optical glass in the study on the expansion, it is also aimed at improving all kinds of new varieties of optical glass of the physical and the physical and chemical properties. And the production process was a lot of work.
  Looking over the course of historical development, can predict the future direction of development of optical glass are:
  ① obtained particularly high refractive index glass;
  ② the relative part of the dispersion obtained special glass;
  ③ Development of infrared and ultraviolet glass;
  ④ replace the glass in some of the undesirable elements such as radioactive THO2, toxic BcO, Sb2O3, etc.;
  ⑤ enhance the chemical stability of glass;
  ⑥ enhance the transparency of glass and prevent glass radiation color;
  ⑦ improve processes, reduce the price of new varieties of glass.