The Experts below are selected from a list of 87087 Experts worldwide ranked by ideXlab platform
P St J Russell - One of the best experts on this subject based on the ideXlab platform.
-
strong circular dichroism for the he11 Mode in twisted single ring hollow Core photonic crystal fiber
Optica, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
-
strong circular dichroism for the he 11 Mode in twisted single ring hollow Core photonic crystal fiber
OPTICA, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
-
optical activity in twisted solid Core photonic crystal fibers
Physical Review Letters, 2013Co-Authors: Thomas Weiss, G K L Wong, Fabio Biancalana, Stephen M Barnett, Miles J Padgett, P St J RussellAbstract:In this Letter we show that, in spectral regions where there are no orbital cladding resonances to cause transmission loss, the Core Mode of a continuously twisted photonic crystal fiber (PCF) exhibits optical activity, and that the magnitude of the associated circular birefringence increases linearly with twist rate and is highly reproducible. In contrast to previous work on twist-induced circular birefringence, PCF has zero linear birefringence and an on-axis Core, making the appearance of circular birefringence rather unexpected. A theoretical Model based on symmetry properties and perturbation theory is developed and used to show that both spin and orbital angular momentum play a role in this effect. It turns out that the degenerate left- and right-circularly polarized Modes of the untwisted PCF are not 100% circularly polarized but carry a small amount of orbital angular momentum caused by the interaction between the Core Mode and the hollow channels.
Jacques Albert - One of the best experts on this subject based on the ideXlab platform.
-
Selective Excitation of Radially and Azimuthally Polarized Optical Fiber Cladding Modes
Journal of Lightwave Technology, 2013Co-Authors: M. Z. Alam, Jacques AlbertAbstract:The dominant polarization properties of the cladding Modes excited by tilted fiber Bragg gratings are investigated. Even in conventional cylindrically symmetric fibers, by orienting the input Core Mode polarization with respect to the tilt plane of the grating cladding Modes with near complete radial or azimuthal polarization can be excited at well separated wavelengths, as confirmed by experiments.
-
tilted fiber bragg grating sensors
Laser & Photonics Reviews, 2013Co-Authors: Jacques Albert, Liyang Shao, Christophe CaucheteurAbstract:Optical fiber gratings have developed into a mature technology with a wide range of applications in various areas, including physical sensing for temperature, strain, acoustic waves and pressure. All of these applications rely on the perturbation of the period or refractive index of a grating inscribed in the fiber Core as a transducing mechanism between a quantity to be measured and the optical spectral response of the fiber grating. This paper presents a relatively recent variant of the fiber grating concept, whereby a small tilt of the grating fringes causes coupling of the optical power from the Core Mode into a multitude of cladding Modes, each with its own wavevector and Mode field shape. The main consequence of doing so is that the differential response of the Modes can then be used to multiply the sensing modalities available for a single fiber grating and also to increase the sensor resolution by taking advantage of the large amount of data available. In particular, the temperature cross-sensitivity and power source fluctuation noise inherent in all fiber grating designs can be completely eliminated by referencing all the spectral measurements to the wavelength and power level of the Core Mode back-reflection. The Mode resonances have a quality factor of 105, and they can be observed in reflection or transmission. A thorough review of experimental and theoretical results will show that tilted fiber Bragg gratings can be used for high resolution refractometry, surface plasmon resonance applications, and multiparameter physical sensing (strain, vibration, curvature, and temperature).
-
two dimensional fiber optic vector vibroscope using only one multi Mode tilted fiber grating
OFS2012 22nd International Conference on Optical Fiber Sensors, 2012Co-Authors: Tuan Guo, Bai-ou Guan, Yang Ran, Yannan Tan, Shuai Gao, Lipeng Sun, Jacques AlbertAbstract:Orientation-recognized two-dimensional vibration sensor based on a polarization-controlled cladding-to-Core recoupling is demonstrated experimentally. A compact structure in which a short section of multi-Mode fiber stub containing a weakly tilted fiber Bragg grating (TFBG) is spliced to another single-Mode fiber without any lateral offset. Several well defined lower-order cladding resonances in reflection show different polarization dependence due to the tilted grating vector excitation. Both orientation and amplitude of the vibration can be determined unambiguously via dual-path power detection of the orthogonal-polarimetric odd-cladding-Modes. Meanwhile, the unwanted power fluctuations and temperature perturbations can be definitely removed via Core Mode monitoring.
-
reflective tilted fiber bragg grating refractometer based on strong cladding to Core recoupling
Optics Express, 2009Co-Authors: Tuan Guo, Hwayaw Tam, Peter A Krug, Jacques AlbertAbstract:A novel in-fiber structure for power-referenced refractometry with the capability to measure surrounding refractive index (SRI) as low as 1.33 is proposed and demonstrated. A short optical fiber stub containing a weakly tilted Bragg grating is spliced to another fiber with a large lateral offset. The reflection from this structure occurs in two well-defined wavelength bands, the Bragg reflected Core Mode and the cladding Modes. The cladding Modes reflect different amounts of power as the SRI changes, while the Core-Mode reflection from the same weakly tilted FBG remains unaffected by the SRI. The power reflected in the Core Mode band can be used as a reliable reference to cancel out any possible power fluctuations. The proposed refractometer with improved sensitivity for low SRI measurement together with the tip-reflection sensing feature, is a good candidate for sensing in chemical and biological applications.
G K L Wong - One of the best experts on this subject based on the ideXlab platform.
-
strong circular dichroism for the he11 Mode in twisted single ring hollow Core photonic crystal fiber
Optica, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
-
strong circular dichroism for the he 11 Mode in twisted single ring hollow Core photonic crystal fiber
OPTICA, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
-
optical activity in twisted solid Core photonic crystal fibers
Physical Review Letters, 2013Co-Authors: Thomas Weiss, G K L Wong, Fabio Biancalana, Stephen M Barnett, Miles J Padgett, P St J RussellAbstract:In this Letter we show that, in spectral regions where there are no orbital cladding resonances to cause transmission loss, the Core Mode of a continuously twisted photonic crystal fiber (PCF) exhibits optical activity, and that the magnitude of the associated circular birefringence increases linearly with twist rate and is highly reproducible. In contrast to previous work on twist-induced circular birefringence, PCF has zero linear birefringence and an on-axis Core, making the appearance of circular birefringence rather unexpected. A theoretical Model based on symmetry properties and perturbation theory is developed and used to show that both spin and orbital angular momentum play a role in this effect. It turns out that the degenerate left- and right-circularly polarized Modes of the untwisted PCF are not 100% circularly polarized but carry a small amount of orbital angular momentum caused by the interaction between the Core Mode and the hollow channels.
Paul Roth - One of the best experts on this subject based on the ideXlab platform.
-
strong circular dichroism for the he 11 Mode in twisted single ring hollow Core photonic crystal fiber
OPTICA, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
-
strong circular dichroism for the he11 Mode in twisted single ring hollow Core photonic crystal fiber
Optica, 2018Co-Authors: Paul Roth, G K L Wong, Yang Chen, M C Gunendi, R Beravat, N N Edavalath, Michael H Frosz, G Ahmed, P St J RussellAbstract:We report a series of experimental, analytical, and numerical studies demonstrating strong circular dichroism for the HE11-like Core Mode in helically twisted hollow-Core single-ring photonic crystal fiber (SR-PCF), formed by spinning the preform during fiber drawing. In the SR-PCFs studied, the hollow Core is surrounded by a single ring of nontouching capillaries. Coupling between these capillaries results in the formation of helical Bloch Modes carrying orbital angular momentum. When twisted, strong circular birefringence appears in the ring, so that coupling to the Core Mode is possible for only one circular polarization state. The result is a SR-PCF that acts as a circular polarizer, offering 1.4 dB/m for the low-loss polarization state and 9.7 dB/m for the high-loss state over a 25 nm band centered at 1593 nm wavelength. In addition, we report for the first time that the vector fields of the helical Bloch Modes are perfectly periodic when evaluated in cylindrical coordinates. Such fibers have many potential applications, such as generating circularly polarized light in gas-filled SR-PCF and realizing polarizing elements in the deep and vacuum ultraviolet.
F Benabid - One of the best experts on this subject based on the ideXlab platform.
-
hypocycloid shaped hollow Core photonic crystal fiber part i arc curvature effect on confinement loss
Optics Express, 2013Co-Authors: Benoit Debord, M Alharbi, T D Bradley, Coralie Fourcadedutin, Yingying Wang, L Vincetti, Frederic Gerome, F BenabidAbstract:We report on numerical and experimental studies showing the influence of arc curvature on the confinement loss in hypocycloid-Core Kagome hollow-Core photonic crystal fiber. The results prove that with such a design the optical performances are strongly driven by the contour negative curvature of the Core-cladding interface. They show that the increase in arc curvature results in a strong decrease in both the confinement loss and the optical power overlap between the Core Mode and the silica Core-surround, including a modal content approaching true single-Mode guidance. Fibers with enhanced negative curvature were then fabricated with a record loss-level of 17 dB/km at 1064 nm.
-
optical properties of low loss 70db km hypocycloid Core kagome hollow Core photonic crystal fiber for rb and cs based optical applications
Journal of Lightwave Technology, 2013Co-Authors: T D Bradley, Benoit Debord, M Alharbi, Coralie Fourcadedutin, Yingying Wang, Frederic Gerome, Benoit Beaudou, F BenabidAbstract:We report on hypocycloid Core shaped hollow-Core Kagome fiber with a record loss of 70 dB/km at a spectral range of around 750-850 nm, which is compatible with Cs and Rb based applications. The fiber exhibits a single Mode operation in a Core diameter as large as 40 μm, and very low sensitivity to bend. We show experimentally that the bending-loss is limited by coupling between the guiding Core Mode and the Modes in the cladding holes.
