PROCEEDINGS ARTICLE | February 9, 2007
Proc. SPIE. 6475, Integrated Optics: Devices, Materials, and Technologies XI
KEYWORDS: Refractive index, Beam splitters, Switches, Switching, Interferometers, Dispersion, Silicon, Photonic crystals, Electromagnetic radiation, Light wave propagation
We present a reconfigurable, compact, low loss, optical switch in silicon. The device utilizes the self-collimation
properties of photonic crystal structures and provides a technique for efficiently switching an electromagnetic wave
guided through a pre-engineered dispersion based photonic crystal self-guiding structure. The electromagnetic wave can
be either in the microwave or optical regime based on the constituent materials and dimensions of the photonic crystal
host. We propose that the "loss tangent" of dielectric material in the switching region can be modified by external
"commands" to control the direction of propagation of the self-collimated signal and hence attain switching, thereby redirecting
the light. Based on the geometrical orientation and position of the applied electric field, electromagnetic waves
can be completely redirected (switched), or partially routed towards any arbitrary direction on a Manhattan grid or
network. We have found that the induced loss does not significantly attenuate the waves switched in any direction. The
structure presented can be generalized to an arbitrary N by M interconnected switching network or fabric, where the
switching topology can be dynamically modulated by the application of external fields. To attain switching, the free-carrier
absorption loss of Si is controlled by carrier injection from forward-biased PN junction. The concept device is
designed and analyzed using the FastFDTDTM accelerated hardware based FDTD technology.
