Title :
Optimized second-harmonic generation in asymmetric double quantum wells
Author :
Vurgaftman, Igor ; Meyer, Jerry R. ; Ram-Mohan, L. Ramdas
Author_Institution :
Naval Res. Lab., Washington, DC, USA
fDate :
8/1/1996 12:00:00 AM
Abstract :
We present a theoretical analysis of surface-incidence and waveguide-mode second harmonic generation with detuned intersubband transitions in GaAs-AlGaAs, InGaAs-InAlAs and GaSb-InGaSb-AlGaSb asymmetric double quantum wells. The analysis includes the effects of absorption, saturation, pump depletion, optical carrier heating, mode confinement and competition, and the loss of phase coherence due to waveguide, bulk and resonant intersubband contributions to the refractive index mismatch. Optimal structures have been determined for each material system in both surface-incidence and waveguide-mode geometries. A scheme for maintaining phase matching by incorporation of a separate region with an intersubband transition tuned midway between the first and second harmonic frequencies is analyzed. At 10.6 μm, the maximum conversion efficiency for the optimized InGaAs-InAlAs waveguide-mode device is ≈16% at a pump-beam intensity of 40 MW/cm 2. Furthermore, the same device can be modulated to vanishing second harmonic output power when an electric field of -32 kV/cm is applied
Keywords :
light absorption; optical harmonic generation; optical modulation; optical pumping; optical saturation; optical waveguide theory; optimisation; refractive index; semiconductor quantum wells; symmetry; tuning; 10.6 mum; GaAs-AlGaAs; GaSb-InGaSb-AlGaSb; GaSb-InGaSb-AlGaSb asymmetric double quantum wells; InGaAs-InAlAs; absorption; asymmetric double quantum wells; detuned intersubband transitions; mode competition; mode confinement; optical carrier heating; optimal structures; optimized second-harmonic generation; phase coherence; phase matching; pump depletion; refractive index mismatch; resonant intersubband contributions; saturation; surface-incidence; surface-incidence SHG; theoretical analysis; waveguide-mode geometries; waveguide-mode second harmonic generation; Absorption; Harmonic analysis; Nonlinear optics; Optical harmonic generation; Optical surface waves; Optical waveguide theory; Optical waveguides; Quantum mechanics; Surface waves; Waveguide transitions;
Journal_Title :
Quantum Electronics, IEEE Journal of
