Used for measuring refractive index by using lasers of various wavelengths

A prism coupler is used for measuring refractive index. By measuring the refractive indices at 403, 633 and 825nm wavelengths, the refractive indices at other wavelengths can be calculated.

There is no major restriction on the shape of the specimen, and films and membranes on substrates can be measured. When measuring a membrane on a substrate, not only the refractive index but also the membrane thickness can be measured in a short period of time.