Observation of parasitic mixing in CW-photomixer terahertz sources

In this contribution, we show the influence of parasitic frequency mixing in conventional continuous wave (CW)-photomixing sources, here, in a waveguide integrated PiN-Photodiode, working at telecom wavelength. We correlate the mixing signals by comparing the spectral terahertz emission, with the emission spectra of the lasers, driving the photomixing antenna. For spectral resolved measurements, we use a Michelson interferometer.