  Two dimensional (2D) photonic crystals are well known for its ability to
manipulate the propagation of electromagnetic wave inside the crystal. 1D and
2D photonic crystals are relatively easier to fabricate than 3D because the
former work in the microwave and far infrared regions whereas the later work in
the visible region and requires smaller lattice constants. In this paper,
simulation for a modified 2D PC with two symmetric waveguide channels where a
defect is located inside one of the channel is performed. The simulation
results show that optical switching is possible by modifying the refractive
index of the defect. If more than one structure is applied this feature can
potentially be applied to produce a cascade optical switch.
