Two Schemes for Generating Efficient Terahertz Waves in Nonlinear Optical Crystals with a Mid-Infrared CO ₂ Laser

Abstract

Terahertz wave generation is explored on the basis of difference frequency generation in nonlinear optical crystals with a mid-infrared CO2 laser. The phase-matching angle and the grating period of periodically inverted GaAs in the 100-1000 µm (0.3-3 THz) range are also investigated on the basis of the surface-emitted difference frequency generation. It is found that two schemes of phase-matching-applied collinear phase matching and phase-matchingapplied non-collinear phase matching are efficient to obtain THz waves.

Study on the generation of Efficient Terahertz from cavity phase matching optical parametric oscillator with a GaAs Crystal sheet by CO2 laser

“…Among the variety of nonlinear crystals, GaAs meet the requirements for high transparency in both 10 µm band and relatively high transparency in the THz region. A lot of work has been carried out enhancing THz power [ [4][5][6][7]. We demonstrate a tunable THz source based on the collinear DFG in GaSe crystal with a dual-wavelength CO 2 laser [7].…”

Theoretical Analysis of Efficient Terahertz Difference Frequency Generation in Periodically-Inverted GaAs Crystals

“…Among the variety of nonlinear crystals, GaAs meet the requirements for high transparency in both 10 µm band and relatively high transparency in the THz region. A lot of work has been carried out enhancing THz power [2][3][4][5]. We demonstrate a tunable THz source based on the collinear DFG in GaSe crystal with a dual-wavelength CO 2 laser [4].…”