Soft-glass photonic-crystal fiber transmits singlemode, broadband light
Researchers at the Max Planck Institute for the Science of Light (Erlangen, Germany) have developed the first soft-glass, hollow-core photonic-crystal fiber to offer singlemode broadband light guidance at wavelengths from 750–1050 nm at a transmission loss of only 0.74 dB/m. Such large-core fibers are useful for particle guidance and fluid- and gas-filled device applications.
Soft or compound glasses such as heavy-metal oxides, fluorides, and chalcogenides have much lower melting points than silica glass and have the potential to transmit infrared light for applications in mid-IR spectroscopy, lidar, and materials processing. However, these low-temperature processing points also mean that to date, light-guiding soft-glass fibers have only been demonstrated with solid cores and limited-wavelength transmission capabilities. But by developing a custom-designed spiral-shaped heating element to minimize temperature fluctuations and glass devitrification during the draw process, the research team was able to produce—through fast-feeding and slow-drawing rates—a hollow-core, photonic-crystal fiber from Schott SF6 lead-silicate glass (with a refractive index of 1.82 at 500 nm) consisting of an approximate 30-µm-diameter hollow core surrounded by a six-layer, kagomé-type lattice cladding. Finite-element calculations determined that the unique singlemode confinement of the fiber is due to the presence of triangular interstitial gaps in the fiber geometry created during the draw process, as well as the high index of the glass material.
Contact Xin Jiang at [email protected].
Gail Overton | Senior Editor (2004-2020)
Gail has more than 30 years of engineering, marketing, product management, and editorial experience in the photonics and optical communications industry. Before joining the staff at Laser Focus World in 2004, she held many product management and product marketing roles in the fiber-optics industry, most notably at Hughes (El Segundo, CA), GTE Labs (Waltham, MA), Corning (Corning, NY), Photon Kinetics (Beaverton, OR), and Newport Corporation (Irvine, CA). During her marketing career, Gail published articles in WDM Solutions and Sensors magazine and traveled internationally to conduct product and sales training. Gail received her BS degree in physics, with an emphasis in optics, from San Diego State University in San Diego, CA in May 1986.