K. Moutzouris et al., Efficient second-harmonic generation in birefringently phase-matched GaAs/Al2O3 waveguides, OPTICS LETT, 26(22), 2001, pp. 1785-1787
We report efficient second-harmonic generation of femtosecond pulses in bir
efringently phase-matched GaAs/Al2O3 waveguides pumped at 2.01 mum. By use
of pump pulses of similar to 200-fs duration and type I interaction, practi
cal second-harmonic average powers of up to similar to 650 muW were obtaine
d, with an average input power of similar to 50 mW. Waveguides of four diff
erent widths and two different lengths were investigated, and a normalized
conversion efficiency of greater than 1000% W-1 cm(-2) was obtained for a 1
-mm waveguide. Measurements of pump and second-harmonic spectra provided cl
ear evidence of phase matching and depletion of the pump spectrum. The meas
ured bandwidth of the second harmonic was similar to1.3 nm. From the measur
ements of transmitted pump power at the phase-matching wavelength, pump dep
letions of more than 80% were recorded. (C) 2001 Optical Society of America
.