THz radiation from a [111] InAs wafer using 1.55 /spl mu/m femtosecond laser pulses

Terahertz (THz) radiation from a variety of materials excited with a femtosecond laser has been extensively studied. However, the THz radiation excited by the femtosecond laser pulses with a wavelength of around 1.5 /spl mu/m was reported only by Howells et al. (1995) using an InSb wafer. Since the wavelength of 1.55 /spl mu/m is widely used in the optical fiber communication field, the THz radiation with the 1.55 /spl mu/m laser is of a technological importance to realize photonic microwave applications. In the work, we report the THz radiation from a (lll) InAs wafer using 1.55 /spl mu/m femtosecond laser pulses.