InP/InGaAs photodetector on SOI photonic circuitry

We present an InP-based membrane p-i-n photodetector on a silicon-on-insulator sample containing a Si-wiring photonic circuit that is suitable for use in optical interconnections on Si integrated circuits (ICs). The detector mesa footprint is 50 µm2, which is the smallest reported to date for this kind of device, and the junction capacitance is below 10 fF, which allows for high integration density and low dynamic power consumption. The measured detector responsivity and 3-dB bandwidth are 0.45 A/W and 33 GHz, respectively. The device fabrication is compatible with wafer-scale processing steps, guaranteeing compatibility toward future-generation electronic IC processing

Indium phosphide based membrane photodetector for optical interconnects on silicon

We have designed, fabricated and characterized an InP-based membrane photodetector on an SOI wafer containing a Si-wiring photonic circuit. New results on RF characterization up to 20 GHz are presented. The detector fabrication is compatible with wafer scale processing steps, guaranteeing compatibility towards future generation electronic IC processing

InGaAs/InP membrane photodetector bonded on silicon

We present the design, fabrication and characterization of a compact photodetector suitable for photonic interconnections on electronic ICs. In our approach, the InP-based optical sources and detectors are linked via Si photonic waveguides in an interconnection layer on top of the CMOS circuitry. The photonic device processing is compatible with Si wafer scale fabrication steps, which guarantees compatibility with future ICs manufacture. The detector maskes use of an InP membrane waveguide to couple the light out of the interconnection layer and carry it towards the absorption region. A responsivity of 0.45 A/W and a rather flat frequency response in the 0-20 GHz range were measured

Low TPA and free-carrier effects in silicon nanocrystal-based horizontal slot waveguides

This paper was published in OPTICS EXPRESS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.20.023838 . Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under lawWe present the characterization of the ultrafast nonlinear dynamics of a CMOS-compatible horizontal-slot waveguide with silicon nanocrystals. Results are compared to strip silicon waveguides, and modeled with nonlinear split-step calculations. The extracted parameters show that the slot waveguide has weaker carrier effects and better nonlinear figure-of-merit than the strip waveguides.We acknowledge EU-project PHOLOGIC (FP6-IST-NMP-017158), Spanish Ministry of Science and Innovation SINADEC (TEC2008-06333) and PROMETEO/2010/087 NANOFOTONICA projects and Universidad Politecnica de Valencia for PAID2011/1914 and J. Matres' doctoral grant.Matres Abril, J.; Lacava, C.; Ballesteros García, G.; Minzioni, P.; Cristiani, I.; Fedeli, JM.; Martí Sendra, J.... (2012). Low TPA and free-carrier effects in silicon nanocrystal-based horizontal slot waveguides. Optics Express. 20(21):23838-23845. https://doi.org/10.1364/OE.20.023838S2383823845202

Silicon optical modulators for high data rate applications

Abstract In this work we describe the carrier depletion MZI modulators, slow wave structures for modulation enhancement and the QCSE modulator which are under development in the European HELIOS project and the UK Silicon Photonics project. Introduction High performance silicon optical modulators are key to many silicon based photonic applications. Over the previous decade the development seen in the performance of silicon optical modulators has been vast. Several routes to modulation have been used to overcome the lack of a strong electro optic effect in silicon. These include the plasma dispersion effect, III-V hybrid device fabrication, SiGe devices, Polymer and Strain induced electro-optic effects. Reported performances now regularly range from 10Gbit/s up to 40Gbit/s. HELIOS, which is a European FP7 funded project and the UK silicon photonics project (UKSP), funded by the EPSRC both involve the development of the different photonic components required to form photonic circuits with a range of functionality. Within both projects there is strong modulator activity with carrier depletion based modulation, QCSE modulation and structures to gain enhancement of the modulation effect under development. Carrier depletion modulation Optical modulators based upon free carrier depletion are widely regarded as being the simplest approach to achieve high performance modulation in silicon. They operate by reverse biasing a diode structure which is incorporated in or around an optical waveguide. The depletion of free carriers therefore interacts with the propagating light causing a change in phase through the plasma dispersion effect. Within the HELIOS project two phase modulators based upon this approach are under investigation using both PN and PIPIN diodes. Cross sectional diagrams of these devices are shown in figure 1. The first structure is based in silicon-on-insulator (SOI) of 220nm thickness. The waveguide section and the slab to one side is doped p type. The slab on the other side of the waveguide is then doped n type setting up a pn junction at the edge of the waveguide rib. The concentration of the n type doping is made larger than the p type doping such that the depletion region extends mainly into the waveguide during reverse bias. These lightly doped p and n type regions extend out to meet highly doped regions which in turn provide ohmic contacts to coplanar waveguide electrodes which are used to drive the device. The devic

High Speed Silicon optical modulators

In this paper we describe two silicon based optical modulators that have been fabricated as part of two projects in which the Surrey group is involved, the "UK Silicon Photonics project" funded by the UK Engineering and Physical Sciences Research Council (EPSRC), and the European "HELIOS" project funded by the European Union. The modulators exploit the carrier depletion effect in MZI structures, but have different advantages and disadvantages. One has a performance that is close to polarisation independence, whilst the other demonstrates a very high extinction ratio for a 40Gb/s silicon modulator. Both are shown to operate at 40Gb/s. © 2011 SPIE-OSA-IEEE

High speed silicon optical modulators

In this paper we describe two silicon based optical modulators that have been fabricated as part of two projects in which the Surrey group is involved, the “UK Silicon Photonics project” funded by the UK Engineering and Physical Sciences Research Council (EPSRC), and the European “HELIOS” project funded by the European Union. The modulators exploit the carrier depletion effect in MZI structures, but have different advantages and disadvantages. One has a performance that is close to polarisation independence, whilst the other demonstrates a very high extinction ratio for a 40Gb/s silicon modulator. Both are shown to operate at 40Gb/s

High Speed Silicon optical modulators

In this paper we describe two silicon based optical modulators that have been fabricated as part of two projects in which the Surrey group is involved, the "UK Silicon Photonics project" funded by the UK Engineering and Physical Sciences Research Council (EPSRC), and the European "HELIOS" project funded by the European Union. The modulators exploit the carrier depletion effect in MZI structures, but have different advantages and disadvantages. One has a performance that is close to polarisation independence, whilst the other demonstrates a very high extinction ratio for a 40Gb/s silicon modulator. Both are shown to operate at 40Gb/s. © 2011 SPIE-OSA-IEEE

Comparison of optical passive integrated devices based on three materials for optical clock distribution

We report different passive integrated devices characterization based on three materials (SOI, a-Si:H and SiNx) for the realization of an optical compact link compatible with CMOS technology. The low level of losses obtained on the passive elementary components for the optical link (strip guides, micro bend and MMI beam splitter) shows the feasibility of photonic integration on silicon using amorphous silicon