Terahertz electromagnetic generation via optical frequency difference
Résumé
Electromagnetic generation between 0.1 and 3 terahertz has been demonstrated using ultrafast photodetectors loaded by broadband antennas and pumped by 0.8 µm stable lasers. Ultrashort response times have been achieved by means of low-temperature-grown (LTG) GaAs in a deep submicron interdigited technology. The 3 dB cutoff frequency is around 650 GHz with an expected output power of the order of a few tenths of a microwatt in the lower part of the spectrum, depending on the thermal post-processing conditions. Possible improvements via long wavelength laser pumping and a Fabry–Pérot cavity-like approach are discussed on the basis of a vertical device scheme.