Low-Pump Irradiance To Modulate Thz Waves Driven By Photo-Generated Carriers In An Inas Slab

We theoretically and experimentally study the THz electromagnetic properties of an undoped-InAs slab whose permittivity is optically modified by a photo-generation process. The modulation of the permittivity is calculated by solving the ambipolar rate equation for the free carriers. Experiment results demonstrate that InAs is a promising semiconductor to manufacture fast and efficiently on-chip THz components. We show a high modulation of the THz transmission up to 100% from 0.75 to 1.1THz at very low pump fluence in the continuous wave regime. We also demonstrate a high-speed transmission modulation rate up to the MHz range with a modulated pump.