Integration of high performance silicon optical modulators

We present our recent work on high speed silicon optical modulators developed within the UK silicon photonics and HELIOS projects. Examples of their integration with other photonic and electronic elements are also presented

Heterogeneously integrated III-V/Si single mode lasers based on a MMI-ring configuration and triplet-ring reflectors

In this paper we show that using a DVS-BCB adhesive bonding process compact heterogeneously integrated III-V/silicon single mode lasers can be realized. Two new designs were implemented: in a first design a multimode interferometer coupler (MMI) – ring resonator combination is used to provide a comb-like reflection spectrum, while in a second design a triplet-ring reflector design is used to obtain the same. A broadband silicon Bragg grating reflector is implemented on the other side of the cavity. The III-V optical amplifier is heterogeneously integrated on the 400nm thick silicon waveguide layer, which is compatible with high-performance modulator designs and allows for efficient coupling to a standard 220nm high index contrast silicon waveguide layer. In order to make the optical coupling efficient, both the III-V waveguide and the silicon waveguide are tapered, with a tip width of the III-V waveguide of around 500nm. The III-V thin film optical amplifier is implemented as a 3µm wide mesa etched through to the n-type InP contact layer. In this particular device implementation the amplifier section was 500µm long. mW-level waveguide coupled output power at 20°C and a side mode suppression ratio of more than 40dB is obtained

III-V/Silicon First Order Distributed Feedback Lasers Integrated on SOI Waveguide Circuits

Heterogeneously integrated III-V-on-silicon first order distributed feedback lasers utilizing an ultra-thin DVS-BCB die-to-wafer bonding process are reported. A novel design exploiting high confinement in the active waveguide is demonstrated. 5 mW output power coupled to a silicon waveguide, 40 dB side mode suppression ratio and continuous wave operation up to 60°C is obtained

Performance of 2D-Grating couplers designed through full 3D-FDTD numerical simulations

By bridging the dimensional gap between fiber mode and Silicon On Insulator (SOI) layer thickness, 1D and 2D-Grating couplers (GCs) represent promising solutions to the challenge of coupling light into silicon photonics circuits. Considerable work has been done over the last decade towards optimization 1D-GCs, that nevertheless [1-2] exhibit a very strong sensitivity to the input polarisation state of the fiber, which makes them unsuitable for many inter-system coupling applications. Recently, a new strategy based on a full 3D-FDTD (finite difference time domain) calculations has been proposed to describe 2D-GC operation, and optimize their performance[3]

III-V on silicon transmitters

Recent advances on hybrid III-V/Si transmitters using a wafer bonding technique are reported. In particular, widely tunable III-V/Si lasers exhibiting 45 nm tuning range and hybrid tunable transmitters integrating a silicon Mach-Zehnder modulator are demonstrated