DETERMINATION OF THE REFLECTION COEFFICIENTS OF LASER-LIGHT OF WAVELENGTHS LAMBDA-EPSILON(0.22 MU-M,200 MU-M) FROM THE SURFACE OF ALUMINUM USING THE LORENTZ-DRUDE MODEL

Using four different fitting methods, the applicability of the Lorentz-Drude (LD) model has been investigated for calculating the reflection coefficients of the laser light of wavelengths of lϵ(0.22 mm, 200 mm) from the surface of aluminum. The applicability of the LD model has been established not only in the IR region but also in the visible and UV regions. The values of plasma frequency wp and damping frequency T have been determined. The values of the reflection coefficients calculated by the LD model have been compared with corresponding experimental values. It has been established that in both the far and medium IR region as well as in both the visible and UV, discrepancies are smaller than 3%. The maximum discrepancy is smaller than 7% and occurs in a narrow region (˜l = 0.825 mm), where aluminum strongly absorbs caused by band-band transitions. © 1990 Optical Society of America.