Far-infrared frequency shifting by optically induced gratings in semiconductors

Abstract A first approach to frequency shifting of far-infrared radiation by optically induced “moving” refractive index gratings in semiconductors is reported. The factors determining the performance of this frequency shifting technique are inferred using a one-dimensional analytical model. In a proof-of-principle experiment frequency shifting of 119 μm radiation was observed up to 80 MHz using a 300 mW, 488 nm Ar + laser for optical excitation.