Determination of optical constants of solids by an automaticreflectometer

An absolute reflectance spectrometer was designed. The instrument is based on an Apple II microcomputer which automates data acquisition, curve fitting, Kramers-Kronig integration, and data plotting. In this system, both the positions of the sample and the detectors are fixed during measurement. The reference and sample signals are detected by scanning a mirror which is engaged with a precise stepping motor. The computer controls all the peripheral instruments; therefore the need of continuous attention to the gain control, frequency scanning, and mirror adjustment is eliminated. Versatile software allows the collected data to be easily manipulated and analyzed