THz Output Improvement in a Photomixer with a Resonant-Cavity-Enhanced Structure

We carry out a detailed theoretical study on THz coherent generation in an LTG-GaAs photomixer with a resonant-cavity-enhanced (RCE) structure. In the structure, an improvement in THz output can be achieved by increasing the quantum efficiency. Under optimized structure parameters, the maximum quantum efficiency of the RCE photomixer is 93%, which is 2.82 times higher than that of the case without an RCE structure. The corresponding THz output ratio of the two structures is found to be about eight in the whole range of the lower frequency at the same incident optical power.