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Posted: Dec 06, 2010
Chalcogenide photonics: Fabrication, devices and applications
(Nanowerk News) Recent progress in chalcogenide glass photonics has been driven by scientific and technological challenges in a variety of areas. These range from increased demand for bandwidth in optical communications, to the emergence of bio-health hazards associated with hazardous microorganisms that absorb at mid-infrared wavelengths, to defense applications that require bright mid-infrared sources. Additionally, chalcogenide glass provides a platform for fundamental investigations of light-matter interactions in nanophotonic structures, such as photonic crystals and metamaterials.
To highlight breakthroughs in this area, Optics Express today published a special focus issue on Chalcogenide Photonics: Fabrication, Devices and Applications (http://www.opticsinfobase.org/oe/issue.cfm?volume=18&issue=25). The issue was organized and edited by Benjamin Eggleton, director of the Australian Research Council's Centre for Ultrahigh-bandwidth Devices for Optical Systems and professor at the University of Sydney.
"This focus issue was created with the intent to represent the current state-of-the-art in the field of chalcogenide photonics," said Eggleton. "The combination of their unique optical properties with the flexibility in tailoring the composition and fabrication methodology makes the chalcogenides compelling for photonics research and has stimulated research groups around the world to actively pursue this vibrant area."
Chalcogenide glasses contain as a major constituent one or more of the chalcogen elements from the periodic table (i.e. Sulphur, Selenium and Tellurium, but excluding Oxygen) covalently bonded to other elements such as As, Ge, Sb, Ga, Si, or P. Chalcogenide glasses have been studied since the 1950s due to their amazing optical properties. They have already found important applications in a number of areas, including the electronics industry and in imaging applications. In the last decade there has been renewed interest in these materials because of their unique optical nonlinear and midinfared properties. An optical material is said to be nonlinear if its optical properties depend on the intensity of the light, an effect that can lead to all-optical switching. The chalcogenide's nonlinear optical properties are not only very strong (hundreds of times that of conventional glass), but also extremely fast (on the order of 10s of femtoseconds—the time it takes for light to travel only a fraction of a millimeter). The fast and strong nonlinearity of chalcogenides makes them attractive as ultrafast nonlinear devices, which can operate much faster than state-of-the-art electronics, or in efficient frequency conversion schemes. In contrast to conventional glass, chalcogenide glasses are transmissive well into the mid-infrared region (e.g. sulphides transmit to ~11um) and are photosensitive to visible light.
This special issue reviews recent progress in this field with 13 invited articles from the leading groups in this field. This issue is comprehensive with articles that can be categorized into a number of areas: (i) chalcogenide material and device science, (ii) device fabrication, (iii) applications in nonlinear optics, and (iv) sensing applications.
Key findings and selected papers
The following papers are some of the highlights of the Optics Express focus issue on Chalcogenide Photonics. All are included in volume 18, issue 25 and can be accessed online at http://www.OpticsInfoBase.org/OE.
– A paper from Yokohama National University in Japan and the Japan Science and Technology Agency reports massive optical nonlinearity in chalcogenide photonic crystal waveguides and demonstrates highly efficient nonlinear processes.
"Nonlinear light propagation in chalcogenide photonic crystal slow light waveguides." Keijiro Sukuzi, Toshihiko Baba, Yokohama National University, Japan Science and Technology Agency, p. 26675. (See: http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-18-25-26675.)
– A team of researchers from five institutions in the U.S. and Italy report on novel sensing architectures for mid infrared wavelengths using chalcogenide waveguide resonators. They exploit the chalcogenide photosensitivity to post-trim resonators and compensate for fabrication imperfections.
"Integrated chalcogenide waveguide resonators for mid-IR sensing: leveraging material properties to meet fabrication challenges." Nathan Carlie et al., p. 26728 (See: http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-18-25-26728.)