ABSTRACT
We demonstrate optical waveguides fabricated in periodically poled MgO-doped stoichiometric lithium tantalate crystals using an fs-laser direct-write process. Two different waveguide architectures were developed: depressed cladding and stress-induced waveguides. Our strain-optic simulations confirmed the guiding mechanism for either case. We demonstrate designs optimized for low propagation loss (0.52 dB/cm) for both fundamental (1050 nm) and second-harmonic wavelengths (525 nm). Low-power CW second-harmonic-generation studies show normalized efficiencies comparable to that of annealed reverse-proton-exchange waveguides in lithium niobate. High-power studies demonstrate second-harmonic power levels up to 8.5 W in a single-pass configuration, using a 1-nm bandwidth CW IR fiber laser as a pump.
ABSTRACT
The generation of cubicon pulses from an Yb fiber chirped pulse amplification system at pulse energies up to 200 microJ is demonstrated. After pulse compression 650 fs pulses with a pulse energy of 100 microJ are obtained, where pulse compression relies on the compensation of third-order dispersion mismatch between the stretcher and compressor via self-phase modulation of the cubicon pulses in the fiber amplifier. Values of self-phase modulation well in excess of pi can be tolerated for cubicon pulses, allowing for the nonlinear compensation of very large levels of dispersion mismatch between pulse stretcher and compressor.
