Nonlinear properties of and nonlinear processing in hydrogenated amorphous silicon waveguides.

We propose hydrogenated amorphous silicon nanowires as a platform for nonlinear optics in the telecommunication wavelength range. Extraction of the nonlinear parameter of these photonic nanowires reveals a figure of merit larger than 2. It is observed that the nonlinear optical properties of these waveguides degrade with time, but that this degradation can be reversed by annealing the samples. A four wave mixing conversion efficiency of + 12 dB is demonstrated in a 320 Gbit/s serial optical waveform data sampling experiment in a 4 mm long photonic nanowire.

Generation of correlated photons in hydrogenated amorphous-silicon waveguides.

We report the first (to our knowledge) observation of correlated photon emission in hydrogenated amorphous-silicon waveguides. We compare this to photon generation in crystalline silicon waveguides with the same geometry. In particular, we show that amorphous silicon has a higher nonlinearity and competes with crystalline silicon in spite of higher loss.

Continuous wave photon pair generation in silicon-on-insulator waveguides and ring resonators.

Silicon waveguides are promising chi(3)-based photon pair sources. Demonstrations so far have been based on picosecond pulsed lasers. Here, we present the first investigation of photon pair generation in silicon waveguides in a continuous regime. The source is characterized by coincidence measurements. We uncover the presence of unexpected noise which had not been noticed in earlier experiments. Subsequently, we present advances towards integration of the photon pair source with other components on the chip. This is demonstrated by photon pair generation in a Sagnac loop interferometer and inside a micro-ring cavity. Comparison with the straight waveguide shows that these are promising avenues for improving the source. In particular photon pair generation in the micro-ring cavity yields a source with a spectral width of approximately 150 pm resulting in a spectral brightness increased by more than 2 orders of magnitude.

Spontaneous growth of Raman Stokes and anti-Stokes waves in fibers.

Using the quantum theory of light, we derive general analytical expressions of Stokes and anti-Stokes spectral photon-flux densities that are spontaneously generated by a single monochromatic pump wave propagating in a single-mode optical fiber. We validate our results by comparing them with experimental data. Limiting cases corresponding to interesting physical situations are discussed.