Characteristics of dual-wavelength vertical-cavitysurface-emitting lasers

Abstract

Based on asymmetric one-dimensional photonic crystal structure,a dual-wavelength vertical-cavity surface-emitting laser (VCSEL) with modified standing wave field distribution has been constructed. The defect layer is Al0.8Ga0.2As with 5λ/4 thickness. Specifically, the dual-wavelength output spectrum of the VCSEL has low absorption loss, easy wavelength adjustment and same output direction. In addition, the two wavelengths and their spacing could be tuned by changing the refractive index contrast of the asymmetric PC structure and the thickness of defect layer. Such dual-VCSEL structure can be applied in optical bistable switches, amplifiers, modulators and detectors, etc..