排序方式: 共有62条查询结果,搜索用时 15 毫秒
31.
The impact of ice 1h formation inside the holes of a photonic crystal fiber Bragg grating was analyzed and discussed. As a result of the ice's expansion, a broadening of the grating spectrum was observed that corresponds to internal microbending of the fiber and after some temperature cycling leads to failure of the fiber. An analytical model with which to estimate the internal compression forces is proposed, and the calculated values are found to be in agreement with reported data. 相似文献
32.
M. Lancry N. Groothoff S. Guizard W. Yang B. Poumellec P.G. Kazansky J. Canning 《Journal of Non》2009,355(18-21):1057-1061
The infrared femtosecond laser damage threshold is found to be independent of OH content in pure silica glass. Additionally, the density and the mean trapping time of electrons excited in the conduction band are also found to be independent on OH concentration. 相似文献
33.
Photo-hypersensitisation of optical waveguides allows significant reduction of UV-induced attenuation during subsequent photolytic writing of gratings and other components. Within phosphosilicate fibres these losses can be eliminated across the entire near UV to near IR spectrum opening up the possibility of UV-written waveguide components at any wavelength. 相似文献
34.
Hydrogen-loaded fibers were exposed to solar radiation for 20 days, in which time the hydrogen was allowed to out-diffuse. Gratings written in these fibers show an increased photosensitivity compared with pristine fibers. Results show the solar radiation has a similar effect on both stripped and unstripped fibers. This work agrees with the fundamental process of using low fluence, long UV sources to photosensitize hydrogen-loaded, germanium-doped fibers. 相似文献
35.
Huyang G Canning J Åslund ML Naqshbandi M Gibson B Petermann I Stocks D Crossley MJ 《Optics letters》2011,36(11):1975-1977
We constructed a type of sensor by depositing a solgel layer within the interior holes of a silica-structured fiber and, subsequently, coating this with an acid-responsive porphyrin. Protonation of the porphyrin by an acidic gas (HCl in this case), is detected by a large change in the visible spectrum. Compared to previous work on a liquid-core sensor in a structured optical fiber, the signal-to-noise ratio of this gas sensor shows a reduced signal strength, but the detection rate is increased about fortyfold. 相似文献
36.
We present thermally regenerated fiber Bragg gratings in air-hole microstructured fibers for high-temperature, hydrostatic pressure measurements. High-temperature stable gratings were regenerated during an 800 °C annealing process from hydrogen-loaded Type I seed gratings. The wavelength shifts and separation of grating peaks were studied as functions of external hydrostatic pressure from 15 to 2400 psi, and temperature from 24 °C to 800 °C. This Letter demonstrates a multiplexible pressure and temperature sensor technology for high-temperature environments using a single optical fiber feedthrough. 相似文献
37.
Inhibition of Cu-amyloid-β by using bifunctional peptides with β-sheet breaker and chelator moieties
Jensen M Canning A Chiha S Bouquerel P Pedersen JT Østergaard J Cuvillier O Sasaki I Hureau C Faller P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(16):4836-4839
Breaking the mold: Inhibition of toxic amyloid-β (Aβ) aggregates and disruption of Cu-Aβ with subsequent redox-silencing of Cu have been considered promising strategies against Alzheimer's disease. The design and proof of concept of simple peptides containing a Cu-chelating/redox-silencing unit and an Aβ-aggregation inhibition unit (β-sheet breaker) is described (see scheme). 相似文献
38.
Conventional hydrogen loading of phosphosilicate optical fibers at relatively low temperatures (80 degrees C) is sufficient to enhance the fiber's photosensitivity after hydrogen outdiffusion, allowing permanent Bragg grating structures to be produced. Thermal sensitization is proposed to be a major contributor to stable index change. 相似文献
39.
Canning J 《Optics letters》2004,29(8):815-817
Recent dramatic improvements in photosensitivity gas mixtures when very low hydrogen concentrations (as low as 0.1%) were used are shown to involve condensation of the host gas. The vapor pressure of the host determines the effective partial pressure of the hydrogen, and this accounts for the bulk of the observed enhancements. 相似文献
40.
A narrow-bandpass filter with a 15-dB signal-to-noise level is demonstrated using Bragg-grating assisted mode conversion within a tapered waveguide. The potential effects of such filters in wavelength-division multiplexing systems are discussed. 相似文献