Broadband Spectro-Spatial Characterization of CW Terahertz Photoemitter Using CMOS Camera

Decoupling the desired spectral signal from scattering events and also from the sporadic signals from the background has been a challenge for fulfilling the promise of real-time applications exhibited by the present broadband terahertz devices. Performing imaging in conjunction with spectroscopy will circumvent this issue, thereby improving the accuracy of the measurement. In this work, the spatial profiles of a widely used CW antenna coupled terahertz photomixer are experimentally investigated using a well-calibrated 32\times 32 pixel CMOS terahertz camera in a broad frequency range from 0.2-0.95 THz. The frequency dependent emission of the THz photomixer exhibited asymmetric and annular beam profiles with intense side lobes.