Noncascading THz-wave parametric oscillator synchronously pumped by mode-locked picosecond Ti:sapphire laser in doubly-resonant external cavity

Abstract: A noncascading terahertz (THz) wave parametric oscillator synchronously pumped by a mode-locked picosecond Ti:sapphire laser whose average power was less than 1W was demonstrated with a noncollinear phase-matching MgO:LiNbO3 crystal in an external enhancement cavity doubly resonant for both pump (780nm) and signal (781–784nm) waves. In the external cavity, in which the pump wave enhanced so as to reduce the pumping threshold of parametric processes, the signal wave could also resonate and thus be enhanced simultaneously, resulting in a THz wave output at approximately 0.9THz as the idler wave. The novel dual enhancement of pump and signal waves reduced the threshold pumping intensity to approximately 50MW/cm2, which was much lower than that of a conventional externally pumped THz wave parametric oscillator with a crystal. [Copyright &y& Elsevier]