An optical lens is a lens made of optical glass. The definition of optical glass is a glass that has specific requirements for optical properties such as refractive index, dispersion, transmittance, spectral transmittance, and light absorption, and has uniform optical properties. Glass that can change the direction of light propagation and the relative spectral distribution of ultraviolet, visible or infrared light. Optical glass in a narrow sense refers to colorless optical glass; optical glass in a broad sense also includes colored optical glass, laser glass, quartz optical glass, anti-radiation glass, ultraviolet and infrared optical glass, fiber optical glass, acousto-optic glass, magneto-optical glass and photochromic glass. Optical glass can be used to manufacture lenses, prisms, mirrors and windows in optical instruments. Components made of optical glass are key elements in optical instruments.
The glass originally used to make the lens was a bump on an ordinary window glass or wine bottle, and the shape resembled a "crown", which gave the name crown glass or crown glass. The glass at that time was extremely uneven and foamy. In addition to crown glass, there is another flint glass that contains more lead. Around 1790, the Frenchman Pierre·Louis·Junard discovered that stirring glass sauce can make glass with uniform texture. In 1884, Ernst Abbe and Otto Schott of Carl Zeiss founded the Schott Glaswerke AG in Jena, Germany. Within a few years, they developed dozens of optical glasses, among which the high refractive index The invention of barium crown glass is one of the important achievements of SCHOTT Glass Factory.
Optical glass is mixed with high-purity oxides of silicon, boron, sodium, potassium, zinc, lead, magnesium, calcium, barium, etc. according to a specific formula, melted in a platinum crucible at high temperature, and stirred evenly with ultrasonic waves to remove bubbles; then Cool down slowly over time to avoid internal stress in the glass block. The cooled glass block must be measured by optical instruments to check whether the purity, transparency, uniformity, refractive index and dispersion rate meet specifications. The qualified glass block is heated and forged to form an optical lens blank.
The above information is provided by optical lenses manufacturer.