Efficient generation of terahertz pulses from single infrared beams in C/GaAs/C waveguiding heterostructures

The difference-frequency terahertz (THz) pulse generation from Fourier components of a single infrared laser pulse in waveguiding heterostructures is considered. It is shown that a proper choice of the waveguide parameters allows for the significant reduction of the input pulse group-velocity dispersion (GVD). As a result, it is possible to noticeably increase the length of such devices and, consequently, the pump-THz pulse conversion efficiency by employing low absorbing materials with high intrinsic GVD coefficients for their fabrication. A particular example of such a scheme--a C/GaAs/C waveguiding heterostructure--is analyzed, a corresponding conversion rate is found, and ways for its further improvement are considered.