Highly efficient generation of THz radiation in semiconductors under magnetic field

Previously, we have reported the significant enhancement of THz radiation power from InAs under a magnetic field when irradiated with femtosecond optical pulses. In this presentation, we report the spectrum control of this intense THz-radiation by the width of the excitation pulses and magnetic field. A Ti:sapphire laser delivered 100-fsec pulses for the excitation. The sample was non-doped bulk InAs with a [100] surface. A liquid-helium cooled InSb bolometer was provided for detection. The InAs sample was placed 45 degrees to the excitation laser beam path. The magnetic field was applied parallel to the sample. In this geometry, the polarization of the THz radiation was horizontal. The THz-radiation power exhibits almost quadratic dependence on the excitation power and higher magnetic field similar to the previous geometry.