The temperature-dependent optical properties of PECVD deposited amorphous silicon films are determined for radiation wavelengths of 1000 nm up to 2000 nm in a temperature range of up to 1110 K. The measurements are performed at heating rates of over 2300 K/s in order to shift the onset of solid-phase crystallization of the amorphous material to temperatures above 1110 K and to make the optical properties of amorphous silicon accessible for examination. In this work, the laser-based measurement setup, the experimental procedure, the simulation methods, and the resulting material-specific data are shown.