Silicon-based Photonic Crystal Waveguides Research Articles

Analysis of 90° bend photonic crystal waveguide: an application to optical interconnect

In this research, we propose and analyse a two-dimensional photonic crystal having L-shaped bend waveguide to realise a negligible bending loss, nonlinearity and confinement loss at the signal of 1.31 μm and 1.55 μm. The proposed waveguide comprises 9 × 9 circular dielectric rods of silicon with air as background material. Further, finite-difference time-domain method is employed for analysing electric field distribution in order to realise effective area as well as high transmission characteristics of the proposed waveguide. Moreover, numerical formulations are used for simulation of bending loss, nonlinearity and confinement loss in the waveguide with suitable structure parameters (diameter of circular rods, nature of the material, lattice spacing). Again, simulation results revealed that ultra-low bending loss of 0.72 × 10−7 dB/m and 0.93 × 10−7 dB/m is experienced by the waveguide at wavelengths 1.31 μm and 1.55 μm, respectively, for 10 nm diameter of the circular rod, whereas a feeble nonlinearity of 0.085 W−1 km−1 and 0.072 W−1 km−1 is also asserted in the same. Furthermore, simulation outcomes proclaimed a negligible confinement loss of 5.7 × 10−11 and 4.8 × 10−11 for the said wavelengths. Finally, this article discloses that the projected silicon-based photonic crystal waveguide appears to be an apt candidate as optical interconnects for application in photonic integrated circuits.

Derivation of coupled envelope propagation equations in silicon-based photonic crystal waveguides

This paper presents a coupled-mode theoretical framework for deriving the propagation equations of the modal envelope functions in a silicon photonic crystal waveguide (PCW), taking into account the influence of linear coupling, Raman scattering, Kerr effect, two-photon absorption, free-carrier index change, and free-carrier absorption. Compared to previous work in the literature, we include the three-dimensional nature of the carrier density in our calculations, analyze the influence of carrier dynamics in the coupling of the modes, and show how higher-order nonlinear terms can be derived. The framework presented here is useful for analyzing a number of signal-processing schemes based on nonlinear PCWs.

Large optical spectral range dispersion engineered silicon-based photonic crystal waveguide modulator

We present a dispersion engineered slow light silicon-based photonic crystal waveguide PIN modulator. Low-dispersion slow light transmission over 18 nm bandwidth under the silica light line with a group index of 26.5 is experimentally confirmed. We investigate the variations of the modulator figure of merit, V(π) × L, as a function of the optical carrier wavelength over the bandwidth of the fundamental photonic crystal waveguide defect mode. A large signal operation with a record low maximum V(π )× L of 0.0464 V · mm over the low-dispersion optical spectral range is demonstrated. We also report the device operation at 2 GHz.