Design of a high-energy terahertz pulse source based on ZnTe contact grating

A compact, particularly robust, and scalable high-energy THz pulse source is proposed based on optical rectification of femtosecond laser pulses in ZnTe by using a contact grating. It is shown by numerical calculations that diffraction efficiencies as high as 80% and 90% can be achieved with sinusoidal and binary contact grating profiles, respectively, in the 1.4–1.7µm pump wavelength range, where no two-photon absorption is present, thereby allowing higher pump intensities. Detailed design parameters are given. The contact grating technology based on ZnTe or other semiconductors can be an efficient source of intense THz pulses with mJ-level energy.