The objective of the group is to further the study of the physics, technology and applications of quantum well microresonators (QWMs) through discussion and an exchange of expertise. QWMs are formed when a layer of quantum well material is sandwiched between two Bragg stacks. QWMs have proven in the past to have a strong potential for optoelectronic devices and application such as vertical cavity surface emitting lasers (VCSELs) and electro-optic and nonlinear optical modulators and switches. This class of device is strategically important for optical interconnects, optical computing and reprographics. The current state-of-the-art is not sufficient when attempting to exploit these devices in optoelectronic systems. It is the aim of PHOTONS to advance the state-of-the-art by promoting co-operation between the partners through improved communication and networking of personnel.
The fundamental and technological challenges associated with quantum well microresonators (QWM) are being studied. QWMs show great potential for optoelectronic devices and applications such as vertical cavity surface emitting lasers and nonlinear optical modulators and switches.
The consortium has had 2 meetings to date. At the first meeting in Dublin (November 1992) each of the partners gave a summary of the issues they felt were relevant to their research aims and of interest to the Working Group. Workshops (3) identified the most critical issues and possible collaborations in the areas of materials and devices based on charge separation, vertical cavity surface emitting lasers (VCSEL) and strained materials, and fabrication and growth processes. After a further plenary session 6 topics were identified and various members of the group undertook to carry out detailed reviews in these areas and to report on these reviews at the second meeting which was held in Paris in June 1993. These reviews were very useful in defining areas of mutual interest and issues that need to be addressed to advance the study and technology of QWMs.
Several information collaborations have begun between the various members of the consortium. So far these collaborations have taken the form of the sharing of information, materials and expertise. Some resources are available for personnel exchange between members and this is to be encouraged in the future.
The consortium's interests include optical nonlinearities in novel strained, piezo-electric, barrier-reservoir, coupled quantum well and Type II materials, the design, growth (by MBE and MOCVD), fabrication and charatcerisation of these novel materials and devices, the measurement of recombination lifetimes using photoluminesence and pump-probe techniques, the study of bistability and visible operation in VCSELs, the application of optical modulators and switches in optoelectronic systems and the optimisation of growth and fabrication techniques.
The activities of the group have to date consisted of two meetings of the partners. These meetings take the form of presentation and discussion sessions with the emphasis on information sharing and the identification of topical issues. The meetings are held at six monthly intervals and the location is rotated around the partners. Interested parties from outside the consortium attended the last meeting and this participation will be encouraged further throughout the course of the working group. The aims of the meetings are to facilitate information dissemination on research activities, collaboration and joint publications amongst the partners and to discover and discuss new approaches to the challenges in the various areas of interest.
The short-term potential of the group has been achieved through the identification of the challenges in the various areas of interest in the study of QWMs. In the medium term the discussions and collaborations between the partners will lead to a better understanding of the physics and technology of QWMs. The improvements in the design, growth, fabrication and exploitation of QWM devices that will result from this work may allow the deployment of QWM devices in advanced optoelectronic systems.
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