Chethiya Meghawarna Dissanayake

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A deep insight into the inherent anisotropic optical properties of silicon is required to improve the performance of silicon-waveguide-based photonic devices. It may also lead to novel device concepts and substantially extend the capabilities of silicon photonics in the future. In this paper, for the first time to the best of our knowledge, we present a(More)
We present approximate analytical expressions describing nonlinear interaction of two optical waves copropagating inside a silicon waveguide in the presence of linear losses, stimulated Raman scattering, and free-carrier absorption. Our approach avoids the undepleted-pump approximation, which we show to be inadequate to describe accurately the Raman-gain(More)
We present a novel method for maximizing signal gain in continuously pumped silicon-waveguide Raman amplifiers made with silicon-on-insulator technology. Our method allows for pump-power depletion during Raman amplification and makes use of a variational technique. Its use leads to a system of four coupled nonlinear differential equations, whose numerical(More)
Increasing the amplifying efficiency in silicon-oninsulator waveguides plays a crucial role in future adaptation of this technology for integrated optics applications. Such improvements not only lead to a reduced overall footprint size but also the overall reduction in the operating energy consumption of the device. In this paper, we address the design(More)
For the first time to the best of our knowledge, we derive expressions for coordinates of the trajectory on the Poincaré sphere that represent polarization evolution in an arbitrary beam of completely polarized light. Our work substantially extends the mapping function of the Poincaré sphere, and opens up new possibilities for its use in optics. In(More)
This letter focuses on interaction of copropagating and counterpropagating pulses inside silicon-on-insulator waveguides using finite-difference time-domain (FDTD) simulations. To the best of our knowledge, this is the first time that copropagating and counterpropagation regimes have been analyzed and compared within an extended FDTD model that takes into(More)
We investigate the polarization dependence of the spectral broadening of femtosecond pulses inside silicon waveguides by using finite-difference time-domain (FDTD) simulations. Our FDTDmodel includes the anisotropic dependency of predominant nonlinear effects in silicon: Kerr effect, two-photon absorption, and Raman effect. In addition, free-carrier(More)
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