Development of terahertz optical sources for an excitation wavelength of 1.56 μm

Herein, we develop optical sources for the generation of high-intensity terahertz pulses utilizing the heterostructure-mediated photo-Dember effect. In particular, InAs/GaSb/InAs heterostructures that can be operated with an excitation wavelength of 1.56 μm were examined. In order to increase the carrier absorption in the GaSb injection layer, we introduced an InGaSb layer. Increased terahertz radiation was obtained owing to the increased absorption of the InGaSb injection layer.