  Silicon photonics promises to alleviate the bandwidth bottleneck of modern
day computing systems. But silicon photonic devices have the fundamental
problem of being highly sensitive to ambient temperature fluctuations due to
the high thermo-optic (TO) coefficient of silicon. Most of the approaches
proposed to date to overcome this problem either require significant power
consumption or incorporate materials which are not CMOS-compatible. Here we
demonstrate a new class of optical devices which are passively temperature
compensated, based on tailoring the optical mode confinement in silicon
waveguides. We demonstrate the operation of a silicon photonic resonator over
very wide temperature range of greater than 80 degrees. The fundamental
principle behind this work can be extended to other photonic structures such as
modulators, routers, switches and filters.
