Bandwidth10's innovative High-Contrast Grating (HCG) VCSEL technology was developed by the founders while at the University of California, Berkeley. Working with Prof. Chang-Hasnain, Dr. Chase, Dr. Rao and Dr. Huang completed their Ph.D. thesis research on VCSELs with a completely new concept for a top mirror, a High-Contrast Grating (HCG). The HCG (seen below) is a single layer, ultra-thin grating made of a high index material with a sub-wavelength period, which exhibits a much broader reflection band than conventional Distributed Bragg Reflectors (DBR).