Mid-infrared Raman amplification and wavelength conversion in dispersion engineered silicon-on-sapphire waveguides

Abstract

Raman amplification based on stimulated Stokes Raman scattering (SSRS) and wavelength conversion based on coherent anti-Stokes Raman scattering (CARS) are theoretically investigated in silicon-on-sapphire (SOS) waveguides in the mid-infrared (IR) region. When the linear phase mismatch k is close to zero, the Stokes gain and conversion efficiency drop down quickly due to the effect of parametric gain suppression when the Stokes-pump input ratio is sufficiently large. The Stokes gain increases with the increase of k, whereas efficient wavelength conversion needs appropriate k under different pump intensities. The conversion efficiency at exact linear phase matching (k = 0) is smaller than that at optimal linear phase mismatch by a factor of about 28 dB when the pump intensity is 2 GW cm −2 .

Performance evaluation of four-wave mixing in a graphene-covered tapered fiber

“…Therefore, L should satisfy the following relation: For the graphene hybrid structure we considered, when the input power is 10 W and the working wavelength is 1550 nm, the value of the right-hand side of equation (A.4) is 262 μm which is much larger than the optimal fiber length of 34.4 μm. Substituting equation (A.4) into equation (A.3), we Therefore, we can define the maximum phase shift as the FOM to be used as the criterion for the measurement of nonlinear performance of an optical device, as expressed in equation (19).…”

“…Generally, the threephoton absorption (3PA) coefficient is a few orders of magnitude smaller than that of the TPA. Since the TPA effect is relatively heavy in graphene, it is reasonable for the 3PA effect to be ignored [18,19].…”