Active optical fiber devices for which the fiber serves not merely as a passive waveguide, but as a medium to directly modulate, generate, or otherwise manipulate light have played a major role in the telecommunications revolution and are now impacting many other fields from remote sensing to biomedicine. Materials for current active fiber devices are largely limited to those that are compatible with the fiber drawing process. This multidisciplinary and collaborative project between Penn State University and the University of Southampton Optoelectronics Research Centre in the UK focuses on incorporating new materials into optical fibers to allow for new types of active fiber devices. Semiconductors and metals are deposited into the micro- to nano-scale voids of microstructured optical fibers over distances of up to meters via a unique high pressure chemical fluid deposition technique. Thus, the rich optoelectronic functionality of both amorphous and crystalline semiconductors and metals can integrated with the flexible light guiding capabilities of fibers. Lasers, modulators, guides, and detectors should then become possible in a geometry that allows for interactions of semiconductors and metals with waveguided electromagnetic radiation over much longer length scales than can be realized in typical planar device geometries.
The broader impacts of the research included strengthening ties across disciplines and between UK and US research efforts, fostering outreach to K-12 students and underrepresented minorities, and a new approach to optoelectronic integration.
Together with electronic chips, optical fibers are a cornerstone of the modern information age. The are best known for their role in allowing for high speed communications across the continents and oceans. They also have other technological applications as high power lasers, chemical sensors, sensors for security and monitoring industrial processes and much more. This project has developed means to integrate the materials of electronic chips, which are semiconductors such as silicon, with optical fibers. Now the properties of these semiconductor materials can be exploited by fabricating precisely structured semiconductor materials and devices inside optical fibers. New tunable infrared fiber lasers with much higher power outputs than previously possible and based on these semiconductor materials may result, for example. Flexible solar fabrics made from strands of semiconductor solar cells in new geometries appear to also now be possible. Semiconductor devices that may facilitate all-fiber solutions to telecommunications and other technologies were developed. New fibers that allow for conversion of the color/wavelength of light from one value were also developed. Graduate students and postdoctoral fellows who have gone on to jobs in the department of defense, major chemical companies, and major semiconductor companies have been trained in fiber materials, chemical deposition, and electronic devices. This project has also strengthened an international collaboration with the University of Southmpton Optoelectronics Research Centre in the United Kingdom.
