SPOEC - Background and Expertise of Partners

Heriot-Watt University, Edinburgh, Scotland

Investigators: Prof. A. C. Walker, Prof. B. S. Wherrett, Dr M. P. Y. Desmulliez, Dr M. R. Taghizadeh, Dr P. W. Foulk and Dr. J. A. B. Dines

The Heriot-Watt group leads the Scottish Collaborative Initiative in Optoelectronic Sciences (SCIOS) – a five-university collaboration started in 1990 and funded by the UK Engineering and Physical Sciences Research Council. This programme was recently reviewed and funding approved through to July 1998. It has as its main focus the application of optoelectronic techniques to optical information processing and has recently resulted in the development of the InGaAs/CMOS smart pixel devices of the type to be exploited in this new programme.

It should be noted that this (SPOEC) project, by concentrating on generic optical interconnect systems, is significantly different from the work funded under SCIOS, which is directed at optoelectronic computing systems. Of course, there is considerable overlap in the technologies, but we plan to exploit this to the advantage of the proposed project, building on the foundations established within the UK programme. In the context of the crossbar demonstrator, the SPOEC proposal more closely follows on from the, recently completed, "Optically Connected Parallel Machines" project, which was based on a similar free-space matrix-matrix architecture, but with a liquid-crystal switching array.

The Heriot-Watt group has worked for more than 10 years on free-space digital optical computing systems from both the theoretical and experimental angles. As a result it has built up a wealth of relevant expertise in the areas of optical system architectures, semiconductor optoelectronics, lens design, optical coatings, diffractive optics and optomechanical assemblies. In 1989 the group built the first all optical computer, based on the optically bistable devices invented in the Department. Much of this research coincided with the ESPRIT-funded "Workshop on Optical Information Technology" (WOIT) [9], [10] that the group led from 1988 to 1992. It has extensive clean-room facilities (for diffractive- and micro- optics fabrication and optical coatings) and laser/optoelectronics laboratories.

University of Glasgow, Scotland

Investigators: Prof. C. R. Stanley and Dr J. H. Marsh

The University of Glasgow is a founding partner of the SCIOS consortium of Scottish Universities. It has long established and widely recognised expertise in: the growth of III-V semiconductors by solid source molecular beam epitaxy (MBE); the characterisation of III-V semiconductor structures; and the fabrication of a diversity of electronic and opto-electronic devices including MESFETs, HEMTs, pseudomorphic HEMTs, single electron structures, high power and high frequency semiconductor lasers; and semiconductor waveguides, modulators and detectors.

Semiconductor research in Glasgow is underpinned by well equipped laboratories which house: two MBE systems for the growth of complex heterostructures in In(Al,Ga)As on GaAs (both pseudomorphic and strain-balanced) and In(Al,Ga)As-InP; reactive ion etching machines with dedicated etch chemistries for dry processing of devices and integrated circuits; a high resolution electron beam pattern generator (Cambridge Leica EBPG-5) in a class 10 environment for both direct writing and mask production; cleanrooms for device processing to the characterisation stage.

Recent contributions by the University of Glasgow to the SCIOS programme have included the development of high power 980 nm lasers and, of direct relevance to SPOEC, the MBE growth of 1047 nm p-i-n multiple quantum well structures based on strain-balanced In(Al,Ga)As-GaAs heterostructures "Smart pixel" modulator arrays have been designed and fabricated using this material for flip-chip bonding to Si CMOS IC's specified by Heriot-Watt University. The "smart pixel" modulators arrays are elaborate and entail 12 major levels of processing.

Ecole Supérieure d'Electricité, France

Investigators: Prof. M. Goetz, Mr J. L. Gutzwiller, Dr S. Vialle, Prof. R. Kielbasa, Mr A. Gauthier, Dr P. H. Benabes, Prof. A. Pacaud, Mr P. Barreau

The Electronics Group (Gif-sur-Yvette Branch) has been working for over 15 years on IC design and on the development of software tools dedicated to it. Many digital IC's have been designed. Recent examples are: a RISC Processor (300k transistors) dedicated to image processing, a digital filter and a phone dialer. The group has also expertise in hardware description language (VHDL, Verilog) and their applications to synthesis. The technologies that are used are ES2 and AMS. Different software packages are available in the group: CADENCE, ALTERA (for programmable circuits), etc. The group also has expertise in mixed (analogue and digital) circuit (sigma-delta converters). The Optoelectronics and Computer Science group (Metz branch) has research activities in the fields of optoelectronics, nonlinear optics, optical communications and parallelism and neural computing. A current research programme is devoted to the development of optical self-routing techniques by means of photorefractive solitons. Another programme is devoted to self-pumped phase conjugation in photorefractive crystals. The group also has expertise in measurement techniques and high speed free-space optoelectronic communications.

Trinity College, Dublin, Ireland

Investigators: Prof. J. Hegarty (Dept. of Physics), Dr. P. Horan (Trinity/Hitachi Dublin Laboratory)

The optoelectronics group in Trinity College has over ten years' experience of the design and characterisation of multiple quantum well (MQW) modulators. Under an ESPRIT-III programme, studies were made on the design and characterisation of all-optical switching in (strained) MQW Fabry-Perot modulators. This was followed by collaborative work on the design and characterisation of 2-D arrays of electrically addressed Asymmetric Fabry-Perot Modulators (AFPMs). Making large arrays presented many problems not previously encountered with single devices. Two arrays were incorporated in a neural network demonstration built at Trinity College in 1992. In collaboration with Heriot-Watt University, under the HCM Network "OPIP" a more sophisticated neural network demonstrator was built in 1995, utilising the AFPM arrays as both modulators and detectors, operating in current-mode. Continuing investigation of off-axis operation of these devices is currently complemented by work on optical micro-cavities within the ESPRIT program "SMILES".

Paul Scherrer Institute, Zürich, Switzerland

Investigators: Dr K. H. Gulden, Dr M. Moser, Dr P. Riel

PSI is the largest Swiss federal research institute (~1200 staff) situated close to Zürich. Section F3B (Applied Solid State Physics) is situated partly in Zürich with about 60 employees.

The PSI Zürich laboratory has considerable experience in the design, fabrication and development of optoelectronic components and microsystems using microoptical, integrated optical and image sensing elements. It runs a professional III-V technology centre with a well-equipped clean room for the fabrication of lasers and integrated optoelectronic devices and a staff of currently 15 persons. The equipment includes a MOVPE reactor with optical in-situ characterisation for the growth of III-V compounds, plasmatherm ECR dry etching system, Vacutec dual chamber plasma system. Balzers dual source e-beam evaporator for metals, AG Assoc. Rapid Thermal Annealing System, K. Süss MJB 3UV 400 aligner, K&S Ball and wirebonder, etc. For device characterisation several optoelectronic laboratories with dark rooms, optical tables and a wide range of measurement and characterisation equipment are available (Hitachi S-4100 FE SEM, Polaron C/V-characterisation system, PLE spectrometer, temperature controlled micromanipulator probe station, Perkin-Elmer Lambda 9 spectrophotometer, AFM, etc.). The in-house EMCORE MOVPE reactor allows the growth of large VCSEL arrays with the required excellent uniformity. In cooperation with the Institut de Microtechnique in Neuchâtel, Switzerland, highly uniform individually addressable 16×16 VCSEL arrays have already been demonstrated. Recent developments include the realisation of record low threshold VCSELs emitting at 762nm for applications in sensing.