Gino Priem

Optical bistability and pulsating behaviour in Silicon-On-Insulator ring resonator structures

We demonstrate optical bistability in a Silicon-On-Insulator two-bus ring resonator with input powers as low as 0.3mW. We evaluate the importance of the different nonlinear contributions and derive time constants for carrier and thermal relaxation effects. In some cases, we also observe pulsation due to interaction between the dominant nonlinear effects. Such a behaviour may be problematic for possible memory and switching operations. Alternatively, it could be used for (tunable) pulse generation.

Ultrafast all-optical switching by cross-absorption modulation in silicon wire waveguides

We describe the use of two-photon absorption in submicron silicon wire waveguides for all-optical switching by cross-absorption modulation. Optical pulses of 3.2 ps were successfully converted from high power pump to low power continuous-wave signal with a fast recovery time. High speed operation was based on the induced optical absorption from non-degenerate two-photon absorption inside the waveguides.

Linear and Nonlinear Nanophotonic Devices Based on Silicon-on-Insulator Wire Waveguides

We review the basic linear and nonlinear properties of silicon-on-insulator photonic wire waveguides and their application to nanophotonic circuits. We give an overview of the performance and issues of basic circuit elements such as couplers and intersections and review the achievements in linear wavelength-selective elements, as well as nonlinear applications of wires and resonators for high-speed signal processing.

Silicon-on-insulator based nano-photonics: Why, How, What for?

Silicon-on-insulator is rapidly emerging as a versatile platform for a variety of integrated nano-photonic components. This paper discusses the variety of merits offered by this system. The key technological challenges are discussed as well as the potential in multiple application fields.

Impact of absorption mechanisms on Kerr-nonlinear resonator behavior

The effect of both single-photon and two-photon absorption mechanisms on the Kerr-nonlinear behavior of resonant structures is investigated using a semianalytical, one-dimensional model. In particular, two-photon effects may severely degrade the ultrafast, nonlinear potential of these structures. Based on this model, the feasibility of Kerr-nonlinear operation is derived for the AlGaAs and Si material systems.

Resonator-based all-optical Kerr-nonlinear phase shifting: Design and limitations

The design of all-optical phase shifting by means of Kerr-nonlinear resonators is investigated using a one-dimensional analytical model. Dependence on different device parameters and design optimization are discussed. In particular, it is shown that a tradeoff in terms of optical input power and device length is required, which is limited by the signal bandwidth.

Nonlinear effects in ultrasmall Silicon-On-Insulator ring resonators

We investigate the significance of secondary effects caused by free carrier accumulation and subsequent heating on the nonlinear behaviour of ultrasmall Silicon-On-Insulator ring resonators. All-optical bistability based on thermal dispersion was experimentally obtained for an input power of only 0.28mW. At higher powers, pulsating behaviour was observed which is problematic for the stability of thermal memory and switching operations. Using free carrier dispersion, we also demonstrate all-optical wavelength conversion with a pulse length of 10 ns, indicating that bitrates of 0.1 Gb/s are feasible. Also here, the presence of unstable pulsations was observed, leading to significant errors in the converted data pattern.

Ultrafast, all-optical regeneration functionalities inside a Kerr-nonlinear platform

We theoretically investigate the potential of a Kerr-nonlinear resonator for all-optical regeneration. In combination with an optical amplifier, this ultra-compact structure allows for an extremely flexible approach in terms of bandwidth and regenerative strength, which can readily be integrated into future nonlinear platforms

InP-nanocrystal monolayer deposition onto silicon-on-insulator structures

We demonstrate, for the first time, the deposition of an InP nanocrystal monolayer onto a processed silicon-on-insulator substrate containing nanophotonic devices. From the first results, propagation losses of 1.7 dB/mm were obtained for wires coated with InP nanocrystals compared to 0.26 dB/mm for the uncoated case.

Optical bistability analysis inside a two-bus ring resonator

We demonstrate experimentally optical bistability inside a two-bus ring resonator fabricated in silicon-on-insulator with a power of only 680 /spl mu/W. We have analysed the different contributions leading to this bistable behaviour and show that the dominant nonlinear effects are free carrier based.