2.5 Refractive Indices in Ultraviolet and Infrared Range

The refractive indices in the ultraviolet and infrared can be measured down to 157 nm in the ultraviolet and up to 2,325.42 nm in the infrared.

2.6 Internal Transmittance ()

Most types of OHARA optical glass are transparent and colourless because they are composed of very pure materials. However, some optical glasses show remarkable absorption of light near the ultraviolet spectral range. For certain glasses with extreme optical properties, such as high refractive index, absorption extends to the visible range. This not only depends on the chemical composition, but also on unavoidable impurities. In this catalogue the internal transmittance is given - i. e., reflection losses are eliminated. This catalogue lists internal transmittance measurements in the range 280 nm to 2400 nm (10 mm sample thickness). As glass varies slightly from melt to melt, these measured values have been selected from many melts and are considered typical.

Note: Our 13 i-line glass data sheets include internal transmittance measurement values using a sample thickness of 10 mm and 25 mm.