Ultra-high-speed wavelength conversion in a silicon photonic chip

Abstract

We have successfully demonstrated all-optical wavelength conversion of a 640-Gbit/s line-rate return-to-zero differential phase-shift keying (RZ-DPSK) signal based on low-power four wave mixing (FWM) in a silicon photonic chip with a switching energy of only ~110 fJ/bit. The waveguide dispersion of the silicon nanowire is nano-engineered to optimize phase matching for FWM and the switching power used for the signal processing is low enough to reduce nonlinear absorption from two-photon-absorption (TPA). These results demonstrate that high-speed wavelength conversion is achievable in silicon chips with high data integrity and indicate that high-speed operation can be obtained at moderate power levels where nonlinear absorption due to TPA and free-carrier absorption (FCA) is not detrimental. This demonstration can potentially enable high-speed optical networks on a silicon photonic chip.

Forward error correction supported 150 Gbit/s error-free wavelength conversion based on cross phase modulation in silicon

“…The device used in the experiment is a dispersion engineered straight 3.6 mm long silicon nanowire with a cross-sectional dimension of 240 nm × 450 nm (height × width), which includes tapering sections for low-loss interfacing with optical fiber [3]. The device has a silicon-on-insulator (SOI) structure, with the silicon waveguide placed on a SiO 2 /Si substrate.…”

“…At the output, the spectrum of the pump (10 Gbit/s RZ signal) is asymmetrically broadened due to both the Kerr effect (such as SPM) and carrier effects (such as FCA and FCD). The SPM can symmetrically broaden the spectrum, but the FCA and the FCD effects can shift the output spectrum towards shorter wavelengths (so called free-carrier induced blue shift) [3,20]. The combined Kerr effect and carrier effects (as described in section 3) result in the asymmetric sidebands (Fig.…”

“…Furthermore, silicon based wavelength conversion has attracted considerable research interest lately, due to its complementary metal-oxide-semiconductor (CMOS) compatibility, ultra-compactness and potential for integration with electronics [3][4][5][6][7][8][9][10][11][12][13]. One method for silicon based wavelength conversion is using four wave mixing (FWM), which usually requires broadband phase matching [3][4][5][6][7][8][9].…”

“…One method for silicon based wavelength conversion is using four wave mixing (FWM), which usually requires broadband phase matching [3][4][5][6][7][8][9]. Another way to achieve wavelength conversion is using cross phase modulation (XPM) [11][12][13][14].…”

Broadband Polarization-Insensitive Wavelength Conversion Based on Non-Degenerate Four-Wave Mixing in a Silicon Nanowire

“…Recently, nonlinear effects in silicon nanowires have attracted considerable research interests due to compactness, large conversion bandwidth and complementary metal-oxide-semiconductor (CMOS) compatibility. Due to the strong light confinement in silicon nanowires with sub-micron dimensions, the group velocity dispersion (GVD), which is a critical parameter for parametric processes, can be engineered, and thus one can achieve ultra-broadband wavelength conversion [4]- [6] based on four-wave mixing (FWM). The FWM process is normally highly polarization dependent and an efficient FWM process occurs when the input signal and pump waves are both aligned to either the transverse-electric (TE) mode or the transversemagnetic (TM) mode.…”