This paper presents a theoretical and experimental investigation of the self-focusing of a single infrared laser beam in the photorefractive semi-conductor InP : Fe for applications in the telecommunications wavelengths as reconfigurable optical switching. The temporal response of two-wave-mixing in photorefractive InP:Fe under a dc electric field at different temperatures has been studied showing that the temperature as well as the intensity can be used to tune the photorefractive response time. In that way, we analyze both experimentally and theoretically the space-charge field build-up with respect to time and space and provide strong hints on the short time self-focusing of an infrared laser beam in InP:Fe with time response in the range of the microseconds.