For room temperature indium phosphide (InP) at a wavelength of 980 nm (energy = 1.27 eV), the complete index of refraction is n = 3.404 and k = 0.007.
Additional information for this material: the room temperature lowest indirect gap energy is 2.05 eV. See reference for more details. Results communicated here are most accurate between 207 and 826 nm.
 S. Adachi, "Model dielectric constants of Gap, GaAs, GaSb, InP, InAs, and InSb," Phys. Rev. B Vol. 35, No. 14, 15 May, 1987, pp. 7454-7463.
 D. E. Aspnes and A. A. Studna, "Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV," Phys. rev. B Vol. 27, No. 2, pp.985-1009 (1983).