Semiconductors such as GaAs, InP, and Si are transparent in the
near infrared, and have a refractive index on the order of 3.
Sophisticated microfabrication techniques for patterning them on
sub-micron lengthscales exist, and so they make ideal host
materials for engineering wavelength-scale, high-index-contrast
optical components. The high index contrast (as compared to
glass-based optical components) opens interesting new
opportunities for studying fundamental physics, and possibly for
the development of qualitatively new applications.
I will briefly review the relevant fabrication technologies, and
explain why high-index-contrast dielectric texture can have
dramatic effects on both linear and nonlinear optical properties
of these semiconductors. Emphasis will be placed on demonstrating
large second and third order nonlinear response characteristics of
both linear waveguides and 3D microcavities, at relatively low
optical power levels. Recent results on silicon-on-insulator
microcavities with Q values in excess of 30,000 will be presented.