Efficient continuous wave second harmonic generation pumped at 1.55 µm in quasi-phase-matched AlGaAs waveguides (original) (raw)
Related papers
Second-harmonic generation from a first-order quasi-phase-matched GaAs/AlGaAs waveguide crystal
Optics Letters, 2001
We demonstrate, for the first time to our knowledge, the generation of second-harmonic pulses by use of a novel methodology for achieving first-order quasi-phase matching in a semiconductor waveguide crystal. This methodology is based on a periodic modulation of the susceptibility coefficient along the direction of light-beam propagation in which advantage is taken of the fact that x
Second-Harmonic Generation in Suspended AlGaAs Waveguides: A Comparative Study
Micromachines
Due to adjustable modal birefringence, suspended AlGaAs optical waveguides with submicron transverse sections can support phase-matched frequency mixing in the whole material transparency range, even close to the material bandgap, by tuning the width-to-height ratio. Furthermore, their single-pass conversion efficiency is potentially huge, thanks to the extreme confinement of the interacting modes in the highly nonlinear and high-refractive-index core, with scattering losses lower than in selectively oxidized or quasi-phase-matched AlGaAs waveguides. Here we compare the performances of two types of suspended waveguides made of this material, designed for second-harmonic generation (SHG) in the telecom range: (a) a nanowire suspended in air by lateral tethers and (b) an ultrathin nanorib, made of a strip lying on a suspended membrane of the same material. Both devices have been fabricated from a 123 nm thick AlGaAs epitaxial layer and tested in terms of SHG efficiency, injection and ...
Surface-emitting second-harmonic generation in AlGaAs/GaAs waveguides
Optical and quantum …, 2002
We investigate the impact of waveguide properties on the performance of surface-emitting second-harmonic generation (SESHG) devices. Using multi-layer AlGaAs/GaAs ridge waveguides that are optimized for SESHG at fundamental wavelengths k x ¼ 1060 and 1550 nm, we achieve nonlinear cross-sections among the highest reported so far. In these devices, characteristics of the guided fundamental wave strongly determine the SESHG performance: multiple reflections in the longitudinal direction affect the conversion efficiency while higher order lateral waveguide modes modify the SESHG farfield. Both effects are significant for applications of SESHG in integrated photonic circuits.
Optics Letters, 2006
We demonstrate second-harmonic generation (SHG) from sub-micrometer-sized AlGaAs/ Al x O y artificially birefringent waveguides. The normalized conversion efficiency is the highest ever reported. We further enhanced the SHG using a waveguide-embedded cavity formed by dichroic mirrors. Resonant enhancements as high as ϳ10ϫ were observed. Such devices could be potentially used as highly efficient, ultracompact frequency converters in integrated photonic circuits.
Femtosecond second-harmonic generation in AlGaAs Bragg reflection waveguides: theory and experiment
Journal of the Optical Society of America B, 2010
The impact of third-order nonlinearities including self-phase modulation and two-photon absorption on the efficiency of the second-harmonic generation is numerically investigated using the split-step Fourier method in phase-matched Bragg reflection waveguides. Also using the same technique, the adverse effects of group velocity mismatch and group velocity dispersion of the interacting frequencies on the efficiency of the nonlinear process are examined and contrasted for optimal sample design. Using an optimized structure, we report efficient femtosecond second-harmonic generation in monolithic AlGaAs Bragg reflection waveguides for a type II nonlinear interaction. For a 190 fs pulsed pump around 1555 nm with an average power of 3.3 mW, a peak second-harmonic power of 25.5 W is measured in a sample with a length of 1.1 mm. The normalized conversion efficiency of the process is estimated to be 2.0ϫ 10 4 % W −1 cm −2 . Pump depletion is clearly observed when operating at the phase-matching wavelength.
Second harmonic generation in AlGaAs photonic wires using low power continuous wave light
Optics Express, 2011
We report modal phase matched (MPM) second harmonic generation (SHG) in high-index contrast AlGaAs sub-micron ridge waveguides, by way of sub-mW continuous wave powers at telecommunication wavelengths. We achieve an experimental normalized conversion efficiency of ~14%/W/cm 2 , obtained through a careful subwavelength design supporting both the phase matching requirement and a significant overlap efficiency. Furthermore, the weak anomalous dispersion, robust fabrication technology and possible geometrical and thermal tuning of the device functionality enable a fully integrated multi-functional chip for several critical areas in telecommunications, including wavelength (time) division multiplexing and quantum entanglement.
2001
We report efficient second-harmonic generation of femtosecond pulses in birefringently phase-matched GaAs/Al_2O_3 waveguides pumped at 2.01 μm. By use of pump pulses of~ 200-fs duration and type I interaction, practical second-harmonic average powers of up to~ 650μW were obtained, with an average input power of~ 50μW. Waveguides of four different widths and two different lengths were investigated, and a normalized conversion efficiency of greater than 1000% W^-1cm^-2 was obtained for a 1-mm waveguide.
Continuous-wave second harmonic generation in Bragg reflection waveguides
Optics Express, 2009
We report the observation of continuous-wave second harmonic generation for a pump at 1559.9 nm in type-I phase-matched Bragg reflection waveguide using the GaAs/Al x Ga 1−x As material system. For an internal pump power of 94 mW, phase-matched second harmonic power of 23 nW was measured in a waveguide with a length of 1.96 mm and ridge width of 4 μm. The internal conversion efficiency of the process was estimated as 6.8 × 10 −3 %W −1 cm −2 . The full-width at half-maximum bandwidth of the nonlinear process was found to be 0.91 nm.
Efficient second-harmonic generation in birefringently phase-matched GaAs Al 2 O 3 waveguides
Optics Letters, 2001
We report efficient second-harmonic generation of femtosecond pulses in birefringently phase-matched GaAs͞Al 2 O 3 waveguides pumped at 2.01 mm. By use of pump pulses of ϳ200-fs duration and type I interaction, practical second-harmonic average powers of up to ϳ650 mW were obtained, with an average input power of ϳ50 mW. Waveguides of four different widths and two different lengths were investigated, and a normalized conversion efficiency of greater than 1000% W 21 cm 22 was obtained for a 1-mm waveguide. Measurements of pump and second-harmonic spectra provided clear evidence of phase matching and depletion of the pump spectrum. The measured bandwidth of the second harmonic was ϳ1.3 nm. From the measurements of transmitted pump power at the phase-matching wavelength, pump depletions of more than 80% were recorded.