We propose a new hollow-core fiber that employs a rib-waveguide geometry for improved gas or liquid sensing. This
waveguide supports a true guided mode that is connected laterally to the external environment through a hollow slab.
Such designs eliminate the requirement of small transverse holes and open up new opportunities for sensing.
We briefly review recent progress in the fabrication and characterization of air-core photonic band-gap fibers. These are silica fibers with an hexagonal array of air holes in the cladding, and a larger air hole creating the core. Improved structural uniformity transverse to the fiber axis and down the fiber axis has yielded fibers with better transmission characteristics. We have measured a minimum loss of 13 dB/km at 1500 nm for a 100 m length of our fiber. This is a marked improvement over previous loss measurements for air-core fibers of any kind. A comparison of observed spectra and calculated gap modes suggests that coupling between surface modes and core modes may be an important contributor to the remaining loss. We present a detailed analysis of the expected losses associated with mode crossings between the fundamental core mode and surface modes, showing that Lorentzian-shaped loss peaks are predicted.
In recent years several new classes of fibers have emerged based on the same basic technology platform-air/silica microstructures. While all of these fibers act as waveguides, each exhibit different optical properties leading to different applications. Out of these, photonic band-gap fibers are touted as the next generation long-haul transmission fiber. Since light propagates in air or vacuum, these fibers promise lower loss, lower nonlinearity and lower material dispersion. Low chromatic dispersion will undoubtedly be a crucial property of photonic band-gap fibers in long-haul applications. We will present experimental data that shows chromatic dispersion can be as low as tens of ps/nm/km at the transmission-spectrum center.
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.