title: Forward and backward THz-wave difference frequency generations from a rectangular nonlinear waveguide.
abstract: We report forward and backward THz-wave difference frequency generations at 197 and 469 μm from a PPLN rectangular crystal rod with an aperture of 0.5 (height in z) × 0.6 (width in y) mm(2) and a length of 25 mm in x. The crystal rod appears as a waveguide for the THz waves but as a bulk material for the optical mixing waves near 1.54 μm. We measured enhancement factors of 1.6 and 1.8 for the forward and backward THz-wave output powers, respectively, from the rectangular waveguide in comparison with those from a PPLN slab waveguide of the same length, thickness, and domain period under the same pump and signal intensity of 100 MW/cm(2).
authors: Institute of Photonics Technologies, Department of Electrical Engineering, National Tsinghua University, Hsinchu 30013, Taiwan. ychuang@ee.nthu.edu.tw
authors: Yen-Chieh
authors: YC
authors: Huang
authors: Tsong-Dong
authors: TD
authors: Wang
authors: Yen-Hou
authors: YH
authors: Lin
authors: Ching-Han
authors: CH
authors: Lee
authors: Ming-Yun
authors: MY
authors: Chuang
authors: Yen-Yin
authors: YY
authors: Lin
authors: Fan-Yi
authors: FY
authors: Lin
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017711:Nonlinear Dynamics; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055053:Terahertz Radiation