Photometric methods for determining the optical constants and the thicknesses of thin absorbing films: criteria for precise and unambiguous determination of n, k, and d in a wide spectral range

The application of error analysis within a certain algorithm for the most a ccurate and unambiguous determination of refractive index n, absorption coe fficient k, and thickness d of thin absorbing films in a wide spectral rang e is illustrated with three examples. Thin films of a dye, Ag, and Au are s elected because their optical constants (small n for Ag and Au and consider able variations of n and h for the dye films) along with their thinness mak e investigating these thin films difficult. The important steps of the algo rithm that ensure reliable isolation of the physically correct solutions an d maximum accuracy of n and k in the spectral range investigated are also d emonstrated. (C) 2001 Optical Society of America.