Generation of steerable continuous-wave terahertz radiation using large-area photomixer

Generation of continuous-wave (CW) terahertz (THz) radiation with a power of 2µW is demonstrated. Two CW laser beams of wavelengths around 800nm are photomixed in a large-area photomixer to generate a THz radiation of 1.2THz. The utilized photomixer has interdigitated contacts with desirable radiation characteristics in the far-field region. We show that the radiated THz beam is steerable by changing the incidence angles of the CW pump beams. In our experimental setup, the emission direction of the large-area photomixer can be steered by rotating the beam splitter used for beam combining. Using this setup, we are able to steer the THz beam in a range of −30 to +30 degrees.