The possibility of fabricating photonic band-gap (PBG) structures with the
use of silicon technologies is discussed. A numerical approach based on the
finite-difference time-domain technique is employed to investigate the pro
pagation of a light beam through a two-dimensional silicon PEG structure wi
th periodically arranged air cylinders. Numerical simulations demonstrate t
hat a defect in such a structure provides unique opportunities in light-bea
m control. In particular, a subdiffraction-limited light beam can propagate
in such a PEG structure with a defect in a waveguiding mode, offering the
way to solve challenging problems of nonlinear-optical interactions, ultrah
igh spatial resolution, and optical data storage. Applications of silicon P
EG structures for controlling light pulses and light beams are considered.