Scaling of Raman amplification in realistic slow-light photonic crystal waveguides

Abstract

The prospect for low pump-power Raman amplification in silicon waveguides has recently been boosted by theoretical studies discussing the enhancement of nonlinear phenomena in slow-light structures. In principle, the slowing down of either the pump or the signal beam is equivalent in terms of Raman gain, but in the presence of losses, we show that they play different roles in determining the net signal gain. We also investigate the impact of the mode profile in realistic slow-light waveguides on the total gain, an effect that is usually neglected in the context of stimulated Raman scattering. By taking representative losses and mode shapes into account, we provide a realistic estimation of the achievable performance of slow-light photonic crystal waveguides.

Theory of pulsed four-wave mixing in one-dimensional silicon photonic crystal slab waveguides

“…Unlike the case of waves propagating in regular optical media, whose GV can hardly be altered, by varying the geometrical parameters of PhCs one can tune the corresponding GV over many orders of magnitude. Perhaps the most noteworthy implication of the existence of optical modes with significantly reduced GV, the socalled slow-light [38][39][40], is that both linear and nonlinear optical effects can be dramatically enhanced in the slowlight regime [41][42][43][44][45][46][47][48].…”

High-Qresonant modes in a photonic crystal heterostructure nanocavity and applicability to a Raman silicon laser

“…The optical properties reported in this paper will be helpful in studies of Raman Si lasers or amplifiers in other types of PC devices. 22,29,[34][35][36][37][38][39][40]…”

Design of Silicon Photonic Crystal Waveguides for High Gain Raman Amplification Using Two Symmetric TE-Like Slow-Light Modes

“…The advantage of individual design is estimated by calculating a gain factor G.F. ≡S s S p /A R , where S s and S p are slow down factors (S, defined as n g /n si =c/n si v g , c is light velocity in vacuum, n g is group index, and n si is refractive index of silicon) of Stokes and pump signal, respectively [8]. A R is Raman cross section effective area defined by…”

“…Small mode cross section and low group velocity v g in PhC WGs can enhance the Raman gain dramatically. Several designs and experimental observations in PhC WGs have been reported [5][6][7][8]. In previous reports, the group velocity is low enough at the Stokes wavelength, but relatively high at the pump wavelength.…”