An Optically Switched Thyristor as a Thz pulse Source

Sources and detectors in the range of 300-10,000 GHz pose a unique challenge to implementation as semiconductor devices. Transistor oscillators do not have the bandwidth to generate these frequencies/wavelengths and optical devices do not have energy gaps small enough to provide effective stimulated emission. Intersubband transitions do provide these energies. The quantum cascade structure (QCL) is one approach to a THz laser using intersubband transitions. Photoconductive switches activated by high power optical pulses also produce THz emissions. In order to integrate the antenna and the electronics for a communication link, ODIS proposes a modulation-doped quantum well structure with an integrated thyristor as the optical source. THz radiation is produced by the relaxation of hot electrons in a quantum well. Compared to the QCL, the growth is simplified, the tunneling mechanism is replaced by conduction in a field-effect transistor channel, the operating voltage is 2V, the operation is fundamentally suitable for room temperature, and with alternate biasing the identical structure performs THz detection. The optical thyristor is part of an optoelectronic circuit platform, providing integrated electronics with 100’s of GHz bandwidth. In this SBIR, ODIS will develop the optically activated thyristor with integrated antenna output as a source of THz pulses.