THz beam steering using femtosecond laser interference technique

We present a THz beam steering method that is based on the generation of grating lobe(GL) radiation from linear array antenna and interference principle of femtosecond laser beam. THz GL radiation with the bandwidth of 110GHz was generated from a strip-line photoconductive antenna. As the pump beam two femtosecond laser beams were combined with finite angle and produced an interference pattern. We demonstrated that the THz GL radiation can be steered by adjusting the relative incidence angle between two pump beams. The direction of the THz beam was changed by 20 degrees when the incidence angle of one pump beam was only varied by 0.1 degrees.