 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
A New Twist On Fiber Optics
Arlington VA (SPX) Jul 02, 2004 By Twisting Fiber Optic Strands Into Helical Shapes, researchers have created unique structures that can precisely filter, polarize or scatter light. Compatible with standard fiber optic lines, these hair-like structures may replace bulky components in sensors, gyroscopes and other devices. While researchers are still probing the unusual properties of the new fibers, tests show the strands impart a chiral, or "handed," character to light by polarizing photons according to certain physical properties. Victor Kopp of Chiral Photonics in Clifton, N.J., and his colleagues describe the new fibers in the July 2 issue of Science. Several of these fibers, and their applications, are being developed in part with funds from the National Science Foundation (NSF) Small Business Innovation Research program. In conventional optical fibers, light is transmitted from one end to the other through a round core housed within a concentric outer cladding. But, because a circular core does not develop handedness when twisted, the research team wound rectangular-core fibers to create a double helix. When the team tested the twisted fiber, they discovered that some photons left the core and entered the cladding. Photons with the same handedness as the fiber entered the cladding whereas photons with handedness opposite that of the fiber remained in the core. With only a relatively loose twist-roughly 100 microns to form a complete turn-photons with a handedness that coincides with the fiber's twist scatter out of the core at a shallow angle and are trapped in the cladding. With a tighter twist, photons with the same handedness as the fiber scatter at a wider angle, allowing the photons to escape from the cladding into the surrounding space. Only light of a single polarization remains in the fiber. At the tightest twists, roughly one-millionth of a meter to complete a turn, photons with the same handedness as the structure are reflected backwards in the core. Because the environment surrounding the fiber affects the wavelength of the light embedded in the cladding, "loosely" twisted fibers can serve as sensors for pressure, temperature, torque and chemical composition. With moderately twisted fibers, researchers can manipulate the resulting polarized light in useful ways, leading to a range of applications such as gyroscopes for navigation systems, current meters for electric power stations, and chemical and materials analysis equipment. For tightly wound fibers, the amount of twist determines the precise wavelength of the light remaining in the fiber, producing light that is ideal for filter and laser applications. Chiral Photonics is developing manufacturing processes for commercial production of the technology. Using a small filament oven, technicians soften the optical fibers while twisting them, which allows greater control of the process. Community Email This Article Comment On This Article Related Links Chiral Photonics SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Space Technology News - Applications and Research
NGC Chosen To Proceed With Developing Solid-State Laser Technology For Military Applications
Redondo Beach CA (SPX) Jan 09, 2006Northrop Grumman Corporation has been selected to develop "military-grade," solid-state laser technology that is expected to pave the way for the U.S. military to incorporate high-energy laser systems across all services, including ships, manned and unmanned aircraft, and ground vehicles. |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
