Ultra-Wideband PIN-PD THz Emitter with > 5.5 THz Bandwidth.

We present novel PIN photodiode (PD) continuous wave (cw) terahertz (THz) emitters with an increased responsivity and reduced substrate thickness compared to the state-of-the-art. Our improved devices feature up to 4 dB higher output power below 500 GHz with maximum power of -0.53 dBm at 115 GHz and strongly reduced THz absorption of the substrate for frequencies above 3 THz. The latter enables us to measure coherent cw THz spectra with a record bandwidth of 5.5 THz, for the first time, which is 1 THz (22%) more than the state-of-the-art. [ABSTRACT FROM AUTHOR]