Compound semiconductors form the basis of modern optoelectronics technology, enabling specialised devices, such as semiconductor lasers, for applications in areas as diverse as optical data storage, telecommunications, and displays. VECSELs, a category of semiconductor laser, are becoming more and more popular because they offer wavelength flexibility from UV to near infra-red and Watt-level output in high-quality beams. However, existing VECSELs are cumbersome, expensive and of limited performance. VECSELs can be made which operate at a range of wavelengths including 670nm, 850nm, 980nm, 1060nm, 1300nm (demonstrated) and 1500nm and 2.2um (in development) which all depend on the same core IP. The Institute of Photonics team has established a strong track-record in VECSEL research at an international level, and has proprietary know-how and a sound portfolio of related IP. Researchers at the University of Strathclyde have developed a high power VECSEL as a new generation of laser sources for telecommunications applications to overcome the problems with existing VECSELs. With the market so sensitised to developments in this area, there is a real prospect of significant opportunity from exploiting this IP. The funding for this work was supplied by a Scottish Enterprise Proof of Concept award.
One way the new technology has been demonstrated is a custom optically-pumped VECSEL in the 1.3 - 1.6¼m spectral band. It is based on the use of gallium arsenide (GaAs); therefore it offers powerscalability and highly wavelength versatile lasers that can be produced readily and cost-effectively from a semiconductor technology base.
The VECSEL concept combines the benefits of optical (diode) pumping and external cavity geometry to offer power-scalable and highly-wavelength-versatile lasers to be produced readily and cost-effectively from a semiconductor technology base. In addition, it can be mode-locked to produce ultra-short pulses. The extreme short pulse width makes it easy to achieve very high peak laser intensity with low pulse energies. To sum up, the new technology has a simple, compact semiconductor structure and produces a high power output with high beam quality that meets commercial requirements for performance, packaging, manufacturability and cost.
This new technology will be ideal for use in areas requiring efficient coupling of power into optical fibres and accurate wavelength selection and control, such as telecommunications. In the US alone, it is estimated that $23.4 billion was pumped into the communications sector in 2000, with long haul communications generating revenues of approximately $10.3 billion. Despite some decline since 2000, the telecoms market is still a large and a valid market, and it will be an important target to address for commercialisation of these devices in due course. The application of the new technology is not necessarily limited to the telecommunications industry. The IP protects all wavelengths and there are many other important applications to be explored. VECSELs could provide the new source for large displays and for optical data storage. The new technology has potential for use in medical applications, for instance, in photodynamic therapy (PDT) for the treatment of cancer.
Recently, half a Watt has been obtained from a GaInNAs VECSEL at 1.3 microns, this is the first time this type of VECSEL has been demonstrated anywhere in the world. The commercialisation route for the VECSEL devices would be a mix of possible company start-up (where the market was sufficiently well defined, niche, low volume and high value) with licensing of the technology into other areas where markets were higher volume, lower cost and more generic. The technology is protected by patent applications filed by the University of Strathclyde as WO2004/086578 and WO2004/086577. It may be possible to grant licenses exclusive in particular sectors, e.g. telecommunications, optical data storage and displays.
For further information, please contact Research & Knowledge Exchange Services: e: rkes@strath.ac.uk t: 0141 548 3707 f: 0141 552 4409