太赫兹脉冲的产生和检测与.pdfVIP

SEMICONDUCTOR OPTOELECTRONICS Terahertz pulse generation and detection with LT-GaAs photoconductive antenna J. Zhang, Y. Hong, S.L. Braunstein and K.A. Shore Abstract: The characteristics of optically induced teraherz (THz) radiation from a biased low- temperature-grown GaAs (LT-GaAs) photoconductive antenna were investigated using a femtosecond Ti:sapphire laser. The THz pulse radiation from two different LT-GaAs photoconductive antennas were compared and two kinds of THz waveform were observed. Saturation behaviour of the emission of THz radiation is observed by using a CW laser diode to optically pre-bias the emitter antenna. 1 Introduction exhibited by the emitted wave-forms has been the subject of some discussion [11, 12]. In this paper, we report a study on The generation and detection of terahertz (THz) radiation the waveforms characteristics of THz radiation generated using ultrashort pulses has been intensively studied during and detected using LT-GaAs photoconductive antennas. the last decade. THz pulses have found many applications, Two distinct THz waveforms were observed by employing such as THz imaging, THz time-domain spectroscopy for various emitters provided by two groups. In addition we studies of carrier dynamics and intermolecular dynamics in have observed the amplitude and wave-form of THz liquids, and dielectric responses of molecules, polymers, radiation obtained by applying an optical ‘pre-bias’ and semiconductors. The generat