Search results for "Fiber optic"
showing 10 items of 193 documents
Analysis of Fiber Inhomogeneity Using Time-Resolved Acousto-Optic Interaction
2013
Workshop on Specialty Optical Fibers and their Applications 2013, Sigtuna Sweden, 28–30 August 2013
Wavelength-multiplexing system for single-mode image transmission
1997
The expanding use of optical communication by means of optical fibers and the situation of drastically increasing amounts of data to be transmitted urge the exploration of novel systems permitting the transmission of large amounts of spatial information by fiber with smaller spatial resolution. An optical encoding and decoding system is suggested for transmitting one- or two-dimensional images by means of a single-mode fiber. The superresolving system is based on wavelength multiplexing of the input spatial information, which is achieved with diffractive optical elements. Preliminary experimental results demonstrate the capabilities of the suggested method for the one- and two-dimensional c…
Actively mode-locked fiber ring laser by intermodal acousto-optic modulation
2010
We report an actively mode-locked fiber ring laser. A simple and low-insertion-loss acousto-optic modulator driven by standing flexural waves, which couples core-to-cladding modes in a standard single-mode optical fiber, is used as an active mechanism for mode locking. Among the remarkable features of the modulator, we mention its high modulation depth (72%), broad bandwidth (187 GHz), easy tunability in the optical wavelength, and low insertion losses (0.7 dB). The narrowest optical pulses obtained were of 95 ps time width, 21 mW peak power, repetition rate of 4.758 MHz, and 110 mW of pump power.
Excitation and interrogation of whispering-gallery modes in optical microresonators using a single fused-tapered fiber tip
2011
We show that whispering-gallery modes (WGMs) in optical microresonators can be excited and detected using a fused-tapered fiber tip (FTFT). The fabrication of FTFTs is simple and inexpensive; they are robust and allow the excitation and interrogation of the resonances with a single fiber. Excitation of high-Q WGMs in silica microcylinders and microspheres is demonstrated.
Characterization of fiber nonuniformities with ppm resolution using time-resolved in-fiber acousto-optics
2014
Time-resolved acousto-optic interaction using flexural waves enables the characterization of fiber nonuniformities along sections of about 1-2 m. A resolution better than 10 ppm of fiber diameter and core refractive index is demonstrated.
Endlessly single-mode heat-sink waveguide
1998
Recently, a new form of optical fiber, the photonic crystal fiber, has been reported. This fiber has a hexagonal array of submicrometer air holes running along its length and a lattice site without a hole (a line defect) in its center. The defect acts as a core, confining light that travels along the fiber as a guided mode. This structure can be endlessly single mode, never supporting more than one confined mode no matter what the diameter of the core or the wavelength of the light. Having discovered this effect experimentally and provided a qualitative explanation for the observed behavior, we present here a planar version of this fiber. Periodic arrays of parallel planar fins are placed o…
Optical properties of in-vitro biomineralised silica
2012
Silicon is the second most common element on the Earth's crust and its oxide (SiO(2)) the most abundant mineral. Silica and silicates are widely used in medicine and industry as well as in micro- and nano-optics and electronics. However, the fabrication of glass fibres and components requires high temperature and non-physiological conditions, in contrast to biosilica structures in animals and plants. Here, we show for the first time the use of recombinant silicatein-α, the most abundant subunit of sponge proteins catalyzing biosilicification reactions, to direct the formation of optical waveguides in-vitro through soft microlithography. The artificial biosilica fibres mimic the natural spon…
Multicore optical fibres for astrophotonics
2011
We report progress towards multimode (MM) fibre filters for suppressing the OH emission that hinders ground-based observation of the early Universe. Fibre Bragg gratings (FBGs) can filter these narrow spectral lines in single-mode (SM) fibres [1]. Implementing them in MM fibres well-matched to astronomical instruments requires transitions between the MM fibre and several SM fibres [2]. Such hand-crafted “photonic lanterns” require many identical FBGs to be made and spliced in place. Instead we are pursuing the idea in multicore (MC) fibres, Fig. 1(a). The FBG is written at once in all the SM cores. The fibre is jacketed with low-index glass and tapered to form the core and cladding of a MM …
Remote optical monitoring in remotely power assisted passive optical networks
2010
In this paper, the authors present the latest results on a simple and low cost method to achieve a dynamic and flexible network monitoring. By placing several fiber Bragg gratings (FBG) along the passive optical gigabit Ethernet infrastructure (GePON), the proposed modified optical time domain reflectometer (OTDR) is able to monitor the entire system by simply tuning its working wavelength. Furthermore, the optical network terminals (ONT), at the end users premises, have been interconnected to the trunk via an innovative cable able to both carry the optical signal as well as the power supply.
Improving the Design of Ion Track-Based Biosensors
2018
In the last decade we had developed new types of biosensors, by cladding the inner walls of transparent etched swift heavy ion tracks in thin polymer foils with enzymes. The enzymatic reaction products of appropriate analytes penetrating into narrow tracks are enriched in the track’s confinement, and they change the electrical track properties if their charge states differ from those of the analytes. It was yet unknown how to design these sensors so that their best efficiency and highest possible sensitivity is achieved. This requires the accurate knowledge of the optimum track radius and the degree of product enrichment within the tracks. These questions were answered by appropriate experi…