Threshold decrease in intracavity optical parametric oscillator synchronously pumped by mode-locked laser

An intracavity optical parametric oscillator (IOPO) pumped by a continuous-wave (CW) mode-locked laser is experimentally realized. The fundamental cavity and optical parametric oscillator cavity are designed to satisfy synchronous pumping. The output characteristics of signal and idle light are measured. Because of higher fundamental photon intensity in IOPO, the threshold of IOPO is lower than that of an extra-cavity optical parametric oscillator. The spectroscopy of signal light is obtained and the wavelength of idle light can be estimated to be 3.298 mu m from noncritical phase matching. Based on the intensity fluctuation mechanism of fundamental locking, the dynamical model for IOPO pumped by a CW mode-locked laser is developed. The simulated results for the temporal shape of three lights are calculated from the derived rate equations. Because of dispersion, the signal pulse width of the theory is smaller than that of the experiment with the same pump energy. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)