EXPERIMENTAL INVESTIGATION AND NUMERICAL-SIMULATION OF THE INFLUENCE OF RESONATOR-LENGTH DETUNING ON THE OUTPUT POWER, PULSE DURATION AND SPECTRAL WIDTH OF A CW MODE-LOCKED PICOSECOND OPTICAL PARAMETRIC OSCILLATOR

We report on a cw mode-locked non-critically phase matched KTP optical parametric oscillator synchronously pumped by a picosecond Ti:Sapphir e laser. High average signal output power of up to 950 mW over a large tuning range has been achieved. For this OPO the influence of resonat or-length detuning on the output power, pulse duration and spectral ba ndwidth has been investigated. The measured data are in good agreement with the results of a numerical simulation using a split-step Fourier method which considers the group-velocity mismatch, the group-velocit y dispersion and the self-phase modulation. The numerical simulation a lso describes the measured strong pump depletion and its influence on the OPO output and efficiency.