Highly efficient doubling of a high-repetition-rate diode-pumped laser with bulk periodically poled KTP.

An internal doubling efficiency of 64% at 2 MW/cm(2)was obtained in a single-pass configuration with an uncoated, 1-cm-long, bulk periodically poled KTP crystal placed outside the resonator of a pulsed, diode-pumped Nd:YAG laser. An average of 4.8W of green light was obtained from a 7.

Continuous-wave optical parametric oscillator based on periodically poled KTiOPO(4).

We report what is to our knowledge the first demonstration of a continuous-wave optical parametric oscillator (OPO) based on periodically poled KTiOPO(4) . The 10-mm-long flux-grown crystal had a quasi-phase-matched period of 9mum . The pump source was a miniature frequency-doubled Nd:YAG laser, and the threshold power of this doubly resonant device was 51 mW.

Efficient resonant frequency doubling of a cw Nd:YAG laser in bulk periodically poled KTiOPO(4).

A cw Nd:YAG laser was quasi-phase-matched frequency doubled by a bulk periodically poled flux-grown KTiOPO(4) crystal in an external resonant cavity. The conversion efficiency and the second-harmonic power with a pump of 225 mW were 55% and 123.5 mW, respectively.

Efficient quasi-phase-matched frequency doubling with phase compensation by a wedged crystal in a standing-wave external cavity.

In standing-wave enhancement cavities for frequency doubling, second-harmonic fields are generated in both directions of propagation. To add the fields coherently, one should compensate for the phase shifts introduced by dispersive elements in the cavity. We experimentally demonstrate phase compensation in a compact standing-wave frequency-doubling cavity by use of a wedged periodically poled KTP crystal.