Abstract

Development of efficient terahertz (THz) emitters usable with a 1.55-Pm fs-laser is a key issue for constructing a fiber-laser-based terahertz timed-domain spectrometer, which is more compact and cost-effective than those based on other solid-state lasers, such as a mode-locked Ti: sapphire laser. We found bulk InSb is a good candidate for such a THz emitter when its emission efficiency is enhanced by using a lens coupler and a moderate magnetic field at the same time. The enhancement of around 74 times in THz emission amplitude was achieved with an MgO hemispherical lens and a magnetic field ~ 650 mT. The signal level was comparable with that of a typical photoconductive antenna and a dynamic range of more than 10⁶ was confirmed in the observed power spectrum.

© 2011 AOS