Abstract

A new class of planar optics has emerged using near-wavelength period gratings with a large refractive index contrast. This seemingly simple structure lends itself to extraordinary properties, which can be designed top-down based for integrated optics on a silicon substrate. In particular, the near-wavelength gratings with large index contrast wiht its surrounding materials are referred as high-contrast gratings (HCG). The extraordinary features include an ultra broadband (Δλ/λ>30%) high reflectivity (>99%) reflector for surface-normal incident light. Another feature is a high quality-factor resonance (Q>107) with surface-normal emission. We incorporated HCG as a replacement of conventional distributed Bragg reflectors (DBR) in vertical cavity surface emitting lasers (VCSELs) over a wide wavelength range from 850-nm to 1550-nm. We also demonstrated high-Q cavity with surface-normal input/output beam using a single HCG layer. This resonator is formed without a Fabry-Perot cavity!

© 2013 Optical Society of America