Periodically intensity-modulated pulses by optical parametric amplification for multicycle tunable terahertz pulse generation

The superposition of signal and idler pulses in dual-chirped optical parametric amplification is proposed for the efficient generation of intensity-modulated pulses with periodic modulation. Both the duration and the modulation period are easily and independently adjustable. Numerical simulations for a three-stage optical parametric amplifier system predicted an efficiency as high as similar to 50% for about 40 mJ of output pulse energy at a wavelength of 2 mu m. Sources of such intensity-modulated pulses near 1.6 mu m or 2 mu m wavelength, pumped by Ti:sapphire or Yb-doped lasers, can be ideally suited for intense multicycle THz pulse generation with tunable frequency and bandwidth by optical rectification for example in organic, semiconductor, or lithium niobate materials. (C) 2017 Optical Society of America