We present a GaAs-based VCSEL structure, BCB bonded to a Si₃N₄ waveguide circuit, where one DBR is substituted by a free-standing Si₃N₄ high-contrast-grating (HCG) reflector realized in the Si₃N₄ waveguide layer. This design enables solutions for on-chip spectroscopic sensing, and the dense integration of 850-nm WDM data communication transmitters where individual channel wavelengths are set by varying the HCG parameters. RCWA shows that a 300nm-thick Si₃N₄ HCG with 800nm period and 40% duty cycle reflects strongly (<99%) over a 75nm wavelength range around 850nm. A design with a standing-optical-field minimum at the III-V/airgap interface maximizes the HCG’s influence on the VCSEL wavelength, allowing for a 15-nm-wide wavelength setting range with low threshold gain (<1000 cm^-1).

Date Published: 27 February 2015
PDF: 7 pages
Proc. SPIE 9372, High Contrast Metastructures IV, 93720U (27 February 2015); doi: 10.1117/12.2077090

Published in SPIE Proceedings Vol. 9372:
High Contrast Metastructures IV
Connie J. Chang-Hasnain; David Fattal; Fumio Koyama; Weimin Zhou, Editor(s)