Low loss 90o bend photonic crystal waveguide for signal amplification in silicon photonic circuit

This research addresses a 2D photonic crystal structure having 90o bend waveguide, which behaves as optical amplifier at wavelength 1.55 µm and thus find novel application in photonic integrated circuit. The proposed structure consist of 11×11 silicon based circular rod etched on it having air as the background material, where the 90o bend is realised by removing series of silicon rods along the L direction. Numerous geometrical parameters such as radius of circular rods and lattice spacing play key role in regulating the light propagation along the 90o path. Finite difference tome domain (FDTD) computational technique has been utilised to realise the transverse electric field distribution in the 90o bend defect based waveguide structure. The incident and transmitted light intensity are computed through numerical formulations. The simulation upshots revealed that the proposed waveguide behaves as an optical amplifier with feeble bending loss, for some distinct values of radius of circular rods like 225 nm, 220.5 nm, 216 nm. In addition to this, numerically it has been explored that bending loss is in the power of 10–4 at the aforementioned values of the radius of circular rods. Hence, our proposed structure can be a suitable candidate for application in future light wave circuits.