Intracavity Frequency Doubling Effects in Different Picosecond Unstable Resonators with KTP Crystal
Wu Fengtie Zhang Wenzhen (Department of Applied Physics, Huaqiao University, Quanzhou 362011)
By using KTP crystal as intracavity frequency doubling generator of a mode locked Nd∶YAP laser, efficient SHG in colliding pulse mode locked (CPM) unstable resonator with antiresonant ring (ARR) and confocal unstable resonator has been demonstrated. The energy conversion efficiencies are 53.4% and 60.2%, pulse durations in fundamental wave are 8 ps and 18 ps, and the maximum energy fluctuation in second harmonic wave are 10.6% and 12.5%, respectively. The characteristics in both resonators and their experimental results are theoretically analyzed.