Behavior of three waves in Cherenkov phase matched monochromatic terahertz wave generation investigated by numerical analysis

The dynamical behavior of electric fields in Cherenkov phase matched terahertz wave generation was numerically analyzed. The effect of diffraction of the terahertz wave was the dominant factor for efficiency of terahertz wave generation. Tightly-focused pump and signal beams radiated efficient terahertz wave drastically in the transverse direction. Propagating terahertz wave at the Cherenkov angle separated from the pump and signal beams; thus destructive interaction of the three waves under phase mismatched conditions no longer occurred. The effect resulted in continuous pump depletion and efficient energy conversion from the pump wave to the terahertz wave. Our results indicate that complete pump depletion could be achieved with Cherenkov phase matching. (C) 2014 The Japan Society of Applied Physics