Determination of optical properties of absorbing materials: a generalized scheme

A generalized reflectance method for determination of optical properties of absorbing materials is developed and compared with other reflectance methods. In the present scheme the specimen is coated with dielectric transparent layer(s) and the reflectance ratios are measured. This novel scheme of specimen preparation and the method of measurement allow the specimen to be free from surface layers and at the same time account for possible effects of surface roughness. It can be applied to a wide variety of materials regardless of their surface conditions and is particularly useful for metals.