We experimentally demonstrate the fabrication of silicon optical fibers by using the powder-in-tube technique. The fibers are drawn from a preform utilizing a custom-made fiber drawing system. Silicon optical fibers having cladding diameters in the range of 40 to 240 µm, core diameters in the range of 10 to 100 µm, and an approximate overall length of 7 cm have been fabricated. The powder-in-tube technique is versatile and can be utilized to fabricate fibers with different dimensions and core/cladding materials.
Monitoring of gaseous species is important in a variety of applications including industrial process gas monitoring, mine
safety, and homeland security. Fiber optic sensors have been used in a variety of forms to monitor various types of
gaseous species. Optical fiber sensors utilizing both random hole and photonic crystal fibers have been investigated.
One limitation to these types of fiber sensors is the fact that the holes run parallel to the optic axis of the fiber, requiring
gases to diffuse over long distances. Diffusion of gases over long distances through tube sizes which are on the order of
microns is a relatively slow process. This can significantly impact the response time of the sensors which are made from
these types of fibers. This paper presents results on the development of optical fibers for gas sensing applications which
have holes extending in the radial direction as opposed to the longitudinal direction (as in the case of photonic crystal
fibers). The holes are made by a process which utilizes phase separation of the glass matrix at relatively low
temperatures. The secondary phase is removed by subsequent leaching processes, leaving a three dimensionally porous
structure. The porosity is arranged in a stochastic fashion within the fiber. Results of the fiber sensor development and
testing will be presented. The microstructural analysis of the fibers by scanning electron microscopy as well as the
optical characterization of the fibers will be presented. Fabrication procedures for the optical fibers and the optical fiber
sensors will also be described.
Effective response to potentially dangerous environmental situations that can arise requires accurate and real time data on the environment that is being monitored. The ability to respond in an appropriate time frame is determined by the sensitivity and response time of the method used for monitoring. Fiber optic sensors have been used and are capable of detecting chemical compounds within an environment; however the sensitivity and response time of this detection method needs to be improved for many sensing applications. Improving these characteristics can be accomplished by designing the structure of the optical fiber sensor to allow increased response time and sensitivity. Through the introduction of new structures and control of these structures, the sensitivity and response time can be designed for a specific application. We have developed a novel porous optical fiber that has potential applications in chemical and biological agent sensing systems. Sensing capabilities of the optical fiber are a result of the structure that is designed into the fiber. The structure of the fiber developed, results of characterization of the fiber and the methods of analysis employed are presented. Methods used to analyze this new fiber optic sensor include nitrogen absorption porosity data, scanning electron microscopy and optical microscopy, and optical characterizations. The structure of the optical fiber is produced by controlling the processing parameters during the fiber draw as well as post processing stages. Fabrication methods and the processing steps that are used during the fiber optic production are also presented. Effect of altering processing conditions on the sensor structure is detailed and how this affects the performance of the fiber.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.