The development of optical glass and the development of optical instruments are inseparable. The new reform of optical systems often puts new demands on optical glass, thus promoting the development of optical glass. Similarly, the successful trial production of new varieties of glass often reverses the development of optical instruments. The earliest optical materials used to make optical parts were natural crystals. Ancient Assisi was said to use crystals as lenses, while in ancient China, natural tourmaline (tea mirrors) and citrines were used. Archaeologists have proven that in 3,000 years ago in Egypt and in our (Warring States) people could make glass. But glass as a pair of glasses and mirrors began in Venice in the thirteenth century. Engels gave high praise to this in the "Natural Dialectical Method" and considered it to be one of the outstanding inventions of the time. Since then, due to the development of astronomers and navigational sciences, Galileo, Newton, and Descartes have also used telescopes and microscopes. Beginning in the sixteenth century glass has become the main material of the optical components. In the seventeenth century, the achromaticity of optical systems became a central issue in optical instruments. At this time, due to the improvement of the glass composition, lead oxide was introduced into the glass, and Hull obtained the first pair of achromatic lenses in 1729. Since then, the optical glass has been divided into two major categories: enamel and chert glass. In 1768, in South France, a uniform optical glass was produced by first stirring with a clay rod, and the independent optical glass manufacturing industry began to be established. In the mid-nineteenth century, several developed capitalist countries established their own optical glass factories, such as the French Para-Mantu Company (1872), the British Chance Company (1848), and the German Schott Company (1848). )Wait. Optical instruments in the 19th century have developed greatly. On the eve of the First World War, in order to rapidly develop military optical instruments, Germany required to break the limits of the poor optical glass variety. At this time, the famous physicist A member participated in the work of the Schott plant. He added new oxides such as BaO, B2O3, ZnO, P2O3, etc. to the glass and studied its effect on the optical constants of the glass. On the basis of this, the types of glass such as bismuth, boron bismuth and zinc bismuth have been developed, and at the same time, the special relative partial dispersion of vermiculite glass has also been trial-produced. During this period, the variety of optical glass has been greatly expanded, resulting in a more complete camera and microscope objective in optical instruments. Until the 1930s, most of the work was still carried out on the basis of the Schott plant. By 1934, a series of heavy-duty glass was obtained, such as German SK-16 (620/603) and SK-18 (639/555). So far, it can be considered as a stage of development of optical glass. Before and after the Second World War, with the development of various optical instruments such as aerial photography, ultraviolet and infrared spectroscopy instruments, and advanced photographic objective lenses, new demands were placed on optical glass. At this time, the optical glass has correspondingly developed. In 1942, Morey and later scientists from the Soviet Union and Germany introduced thinners and thin oxides into the glass, thus expanding the glass variety and obtaining a series of high-refractive-index, low-dispersion optical glass. Such as Germany LaK, LaF, Soviet CTK and ТЬФ series. At the same time, research on low refractive index large dispersion glass was also carried out and a series of optical glass of fluorotitanate system, such as the Soviet Union -9, ЛФ-12, German F-16 and the like. Since various new types of optical glass have defects in processing or use properties more or less, in the field of expanding optical glass, the physical and physicochemical properties of various new varieties of optical glass are also being improved. And the production process has done a lot of work. Looking at the above historical development process, we can predict that the future development direction of optical glass is: 1 producing a glass with a particularly high refractive index; 2 making a glass with a special relative partial dispersion; 3 development of infrared and ultraviolet optical glass; 4 replace some undesirable components in the glass such as radioactive THO2, toxic BcO, Sb2O3, etc.; 5 improve the chemical stability of the glass; 6 improve the transparency of the glass and prevent the radiation of the glass; 7 Improve the process and reduce the price of new varieties of glass. Plastic Straw for Beverage,Colorful Disposable Plastic Straw,Disposable Plastic Straw Plastic Products,Cups Co., Ltd. , http://www.nstableware.com