Fivefold Peak Power Boost in HBT-Driven GaAs Collapsing-Field-Domain-Based Sub-THz Source

Miniature on-chip sources based on the collapsing field domain phenomenon in GaAs have advanced compact sub-picosecond time-domain imaging schemes operating in the 100–250 GHz frequency range. Efforts have been done to broaden the emission band of on-chip sources towards 400 GHz, but increasing the peak power of the emitted picosecond-range pulses remains physically challenging but practically important. In this work, a fivefold increase in peak power has been achieved by replacing the previously used hetero-bipolar-based collapsing field domain source operating in self-oscillating mode with a bipolar-based source externally pulsed by a hetero-bipolar driver. Importantly, the suggested solution unaffected the compactness of the source and facilitates its application in time domain imaging.