Absorption coefficient of Si in the wavelength region between 0.80–1.16 μm

The absorption coefficient, α as a function of wavelength in the region of 0.80–1.16 μm was determined by the transmission technique. The present α data fit an indirect transition model of L. H. Hall, J. Barden, and F. J. Blatt [Phys. Rev. 99, 559 (1954)]. The α data of W. C. Dash and R. Newman [Phys. Rev. 99, 1155 (1955)] and W. R. Runyan [Southern Methodist University Report SMU 83-13 (1967)] did not fit the indirect transition model. The reflectivity values obtained from transmission data at long wavelengths are less than those of H. R. Philipp and E. A. Taft [Phys. Rev. 120, 37 (1960)] and W. C. Dash and R. Newman. The present surface preparation technique produced a reflection loss slightly lower than would be expected from the surface characteristic of bulk material.