Nonlinear Optical Effects And Optimal Design Of Silicon Waveguides

In recent years, silicon photons have a fast development, and especially for the nonlinearities of silicon waveguide as well as its applications. Silicon waveguides have received considerable interests due to its large Kerr parameter, strong confinement of light, which can be used in nonlinear optics study work. This paper focuses on the optimal designing of silicon waveguide, nonlinear process of femtosecond pulse and wavelength conversion in infrared wave-band, the main results we have achieved are summarized as follows:1. Introducing the research background of silicon waveguides and the significance of nonlinear applications of silicon waveguide. We have discussed the performance of several nonlinear silicon waveguides, and some new kinds of silicon waveguies.2. Considering all the nonlinear effects, the nonlinear propagation equations of ultra-fast optical pulses was derived from the polarization theory. By adjusting the waveguide parameters such as width, the thickness of the slot, and height of the strip waveguide, the waveguide dispersion can be optimized. The effects of self-phase modulation(SPM), free carrier, dispersion properties and initial chirp in this strip silicon waveguide on optical pulses transmission have been studied in detail.3. A strip/slot hybrid waveguide with double horizontal silicon nanocrystals(Si-nc) slots is proposed to achieve flat and low dispersion with four zero dispersion wavelengths. By tuning structural parameters of the waveguide, dispersion tailoring is characterized fully. The bandwidth of flat dispersion exhibits over 800 nm. A broadband supercontinuum spectrum, spanning 2500 nm was generated in this waveguide pumped by femotsecond pulse at 1.86 μm.4. A rig silicon waveguide with optimal dispersion is proposed to achieve wavelength conversion in telecom band. The conversion efficiency and bandwidth of continuous wavelength conversion are 4.7 dB and 470 nm, respectively. The effects of pump power, dispersion properties and waveguide length on wavelength conversion are discussed in detail.