Efficient generation of coherent blue and green light based on frequency conversion in KTiOPO4 crystals

We review our recent results on efficient generation of coherent blue/green light based on different configurations and structures. We have used second-harmonic generation with forward or backward configuration in short-period periodically-poled bulk and waveguide KTP to generate blue light. We have used backward second-harmonic generation to characterize periodically-segmented submicron KTP waveguides. By cascading second-harmonic generation and subsequent sum-frequency generation, we have generated coherent blue light in KTP and/or Ce:KTP crystals. We have also studied damage threshold of bulk KTP; we hope that we can eventually use it towards efficient generation of cw coherent green light.