Optical glass lens

Optical glass is made of high-purity silicon, boron, sodium, potassium, zinc, lead, magnesium, calcium, barium and other oxides mixed according to a specific formula, melted at high temperature in a platinum crucible, stirred evenly with ultrasonic waves to remove air bubbles; Cool down slowly over time to avoid internal stress on the glass block. After cooling, the glass block must be measured by optical instruments to check whether the purity, transparency, uniformity, refractive index and dispersion rate meet the specifications. Qualified glass blocks are heated and forged into optical lens blanks.

Special type of glass lens

Rare Earth Elements

In the 1930s, a new rare earth element optical glass appeared, the main components are oxides of lanthanum, thorium and tantalum. Rare earth element optical glasses have a high refractive index, opening up new possibilities for the design of optical lenses. Lanthanum glass is often found in large aperture lenses today. Thorium glass has been discontinued due to radioactivity.

lead-free light

Lead-free optical glass does not contain lead and arsenic, and is marked with N.

Glass lens classification

Glasses with similar chemical composition and optical properties are also distributed in adjacent positions on the Abbe diagram. The Abbe diagram of SCHOTT Glassworks has a set of straight lines and curves, which divide the Abbe diagram into many zones and classify the optical glass; columns such as crown glass K5, K7, K10 are in zone K, flint glass F2, F4, F5 are in F Area. Symbols in glass names:

F stands for flint K stands for crown B stands for boron BA stands for barium LA stands for lanthanum N stands for lead-free P stands for phosphorus

Physical parameters of glass lens

Vd Abbe number with four significant figures nd Refractive index with seven significant figures Ve with four significant figures ne Density of glass with seven significant figures. Transparency of glass with four significant figures. Coefficient of refractive index change with temperature of four significant figures three significant digits

glass lens glass code

The international glass code is represented by nine digits in the form: xxxxxx.xxx;

The first three digits represent the index of refraction and the first three digits after the decimal point. The next three digits represent the first three digits of the Abbe number Vd, excluding the decimal point. The three digits after the decimal point represent the density of the glass, excluding the decimal point such as K10 glass

nd=1.50137 The first three digits after the decimal point=501 Vd=56.41 The first three digits, without the decimal point=564 Density=2.52; without the decimal point=252 The international glass code for K10 is 501564.252