Surface optical transitions on cleaved InP(110)

The optical transitions at the InP(110) cleaved surface are studied by normal incidence surface differential reflectivity in the spectral range between 1.5 and 4.0 eV. A sharp absorption peak has been detected at 3.1 eV together with smaller transitions at 3.6 and 3.8 eV. A determination of the surface dielectric function has been performed.