View article

We report the coherent generation and detection of ultrabroadband terahertz (THz) radiation using low-temperature-grown GaAs photoconductive antennas as both emitters and receivers. THz radiation with frequency components over 15 THz was obtained, the highest reported for a THz time-domain system based on photoconductive antennas. Such a system has a smooth spectral distribution between 0.3 and 7.5 THz⁠, ideal for spectroscopic applications. In addition, sharp spectral features at 8.0 and 8.8 THz were observed, and explained in terms of optical phonon resonances in the photoconductive antennas.

The coherent generation and detection of terahertz (THz) radiation using ultrashort optical pulses has been investigated intensively during the last decade. The pulse width of commercially available mode-locked Ti: sapphire lasers is approaching 10 fs and, with such ultrashort laser pulses, the spectral …