Generation of High Efficient Quasi-Single-Cycle 3 and 6THZ ‎Pulses using Multilayer Structures OH1/SiO2 and ‎DSTMS/SiO2 ‎

We propose that high efficient terahertz (THz) multilayer structures are composed of ‎DSTMS/SiO2 and OH1/SiO2 at 3 and 6THz frequencies. We show that the efficiencies of these ‎structures are higher than DAST/SiO2 structure in both of 3 and 6THz frequencies. OH1/SiO2 ‎structure at 6THz has an efficiency as large as 10-1; at 3THz frequency, DSTMS/SiO2 structure ‎has an efficiency as large as 10-2. Meanwhile bulk OH1 has an efficiency as large as 10-3 at ‎‎3THz due to perfect phase matching whose efficiency is lower than DSTMS/SiO2 structure. ‎We also show that other structures, namely DSTMS/ZnTe at 3THz and DAST/GaP at 8THz, ‎have low efficiency, so they are not suitable as THz sources.‎