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Full-Text Articles in Physics

Diffractive Optical Elements With A Large Angle Of Operation Recorded In Acrylamide Based Photopolymer On Flexible Substrates, Hoda Akbari, Izabela Naydenova, Lina Persechini, Sean Garner, Pat Cimo, Suzanne Martin Dec 2014

Diffractive Optical Elements With A Large Angle Of Operation Recorded In Acrylamide Based Photopolymer On Flexible Substrates, Hoda Akbari, Izabela Naydenova, Lina Persechini, Sean Garner, Pat Cimo, Suzanne Martin

Articles

A holographic device characterised by a large angular range of operation is under development. The aim of this study is to increase the angular working range of the diffractive lens by stacking three layers of high efficiency optical elements on top of each other so that light is collected (and focussed) from a broader range of angles. The angular range of each individual lens element is important, and work has already been done in an acrylamide-based photosensitive polymer to broaden the angular range of individual elements using holographic recording at a low spatial frequency.This paper reports new results on the …


Microfiber Coupler Based Label-Free Immunosensor, Lin Bo, Christy Charlton O'Mahony, Yuliya Semenova, Niamh Gilmartin, Pengfei Wang, Gerald Farrell Apr 2014

Microfiber Coupler Based Label-Free Immunosensor, Lin Bo, Christy Charlton O'Mahony, Yuliya Semenova, Niamh Gilmartin, Pengfei Wang, Gerald Farrell

Articles

Optical microfibers and related structures which incorporate large evanescent field and minimal size offer new opportunities for biosensing applications. In this paper we report the development of an immunosensor based on a tapered microfiber coupler embedded in a low refractive index polymer. Biomolecules adsorbed on the microfiber coupler surface modify the surrounding refractive index. By immobilizing antigens on the surface of the sensing area, the microfiber coupler was able to operate as a label-free immunosensor to detect specific antibodies. We experimentally demonstrated for the first time the sensing ability of this sensor using a fibrinogen antigen-antibody pair. By monitoring the …


Using Acrylamide Based Photopolymers For Fabrication Of Holographic Optical Elements In Solar Energy Applications, Hoda Akbari, Izabela Naydenova, Suzanne Martin Feb 2014

Using Acrylamide Based Photopolymers For Fabrication Of Holographic Optical Elements In Solar Energy Applications, Hoda Akbari, Izabela Naydenova, Suzanne Martin

Articles

A holographic device is under development that aims to improve light collection in solar cells. The aim is to explore the potential of using photopolymer Holographic Optical Elements (HOE) to collect light from a moving source, such as the sun, and re-direct it for concentration by a holographic lens.. A working range of 45 degrees is targeted for such a device to be useful in solar applications without tracking. A photopolymer HOE is capable of efficiently re-directing light, but the angular selectivity of a single grating is usually of the order of one degree at the thicknesses required for high …


A Photonic Crystal Fiber Based Polarimetric Sensor For Cure Monitoring Of Magneto-Rheological Smart Composite Material, Manjusha Ramakrishnan, Ginu Rajan, Yuliya Semenova, Y. Zhou, Stephen Jerrams, Gerald Farrell Jan 2014

A Photonic Crystal Fiber Based Polarimetric Sensor For Cure Monitoring Of Magneto-Rheological Smart Composite Material, Manjusha Ramakrishnan, Ginu Rajan, Yuliya Semenova, Y. Zhou, Stephen Jerrams, Gerald Farrell

Articles

A buffer stripped high birefringent photonic crystal fibre based polarimetric sensor is developed for monitoring the curing process of magnetorheological elastomer (MRE) smart composite material. Using the developed sensor, different phases of the MRE curing process are clearly visible from the phase shift variation of the embedded polarisation maintaining photonic crystal fibre (PM-PCF) sensor. During the curing process, the buffer stripped PM-PCF exhibits a stress/strain induced phase shift variation from 0 to 1.98 rad. This is a significantly large phase change, which can be used to very clearly identify the different stages in the curing process. For comparison, a fibre …


Experimental Study And Analysis Of A Polymer Fiber Bragg Grating Embedded In A Composite Material, Ginu Rajan, Manjusha Ramakrishnan, Yuliya Semenova, Eliathamby Ambikairajah, Gerald Farrell, Gang-Ding Peng Jan 2014

Experimental Study And Analysis Of A Polymer Fiber Bragg Grating Embedded In A Composite Material, Ginu Rajan, Manjusha Ramakrishnan, Yuliya Semenova, Eliathamby Ambikairajah, Gerald Farrell, Gang-Ding Peng

Articles

The characteristics of polymer fiber Bragg gratings (FBGs) embedded in composite materials are studied in this paper and are compared with characteristics of their silica counterparts. A polymer FBG of 10 mm length which exhibits a peak reflected wavelength circa 1530 nm is fabricated and characterized for this purpose. A silica FBG with a peak reflected wavelength circa 1553 nm is also embedded in the composite material for a comparison study. The fabricated composite material sample with embedded sensors is subjected to temperature and strain changes and the corresponding effects on the embedded polymer and silica FBGs are studied. The …


Suppression Of Raman Soliton Self-Frequency Shift In Photonic Cystal Fibers With Tellurite Subwavelength Core, Shua Wei, Jinhui Yuan, Chongxiu Yu, Sha Li, Boyuan Jin, Xiaoming Hu, Gerald Farrell, Qiang Wu Jan 2014

Suppression Of Raman Soliton Self-Frequency Shift In Photonic Cystal Fibers With Tellurite Subwavelength Core, Shua Wei, Jinhui Yuan, Chongxiu Yu, Sha Li, Boyuan Jin, Xiaoming Hu, Gerald Farrell, Qiang Wu

Articles

A new nonlinear evolution equation including the vector nature of the electromagnetic field and the frequency variation of the mode profile is derived. A kind of new nonlinearity is demonstrated. Its magnitude is strongly dependent on the waveguide geometrical parameters, which will lead to a suppression of the Raman soliton self-frequency shift in a photonic crystal fiber with a tellurite subwavelength core. Our results can be supported by the detailed numerical simulations


Investigation Of The Sensitivity To Humidity Of An Acrylamide-Based Photopolymer Containing N-Phenylglycine As A Photoinitiator, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova Jan 2014

Investigation Of The Sensitivity To Humidity Of An Acrylamide-Based Photopolymer Containing N-Phenylglycine As A Photoinitiator, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova

Articles

Sensitivity of holographic recording materials to the relative humidity (RH) of the environment often restricts their use in fabrication of holographic optical elements and other applications. It is important to develop materials with little or no sensitivity to humidity. In this paper the humidity response of transmission gratings recorded in an acrylamide-based photopolymer containing N-phenylglycine (NPG) as a photoinitiator is studied at RH = 20 – 90 %. The hologram is found to be completely insensitive to humidity at RH below 70 % and its diffraction efficiency remains constant. A decrease in diffraction efficiency is observed at RH = 80 …


Photonic Crystal Fiber Half-Taper Probe Based Refractometer, Pengfei Wang, Ming Ding, Lin Bo, Chunying Guan, Yuliya Semenova, Weimin Sun, Libo Yuan, Gilberto Brambilla, Gerald Farrell Jan 2014

Photonic Crystal Fiber Half-Taper Probe Based Refractometer, Pengfei Wang, Ming Ding, Lin Bo, Chunying Guan, Yuliya Semenova, Weimin Sun, Libo Yuan, Gilberto Brambilla, Gerald Farrell

Articles

A compact singlemode - photonic crystal fibre - singlemode fibre tip (SPST) refractive index sensor is demonstrated in this paper. A CO2 laser cleaving technique is utilsed to provide a clean-cut fibre tip which is then coated by a layer of gold to increase reflection. An average sensitivity of 39.1 nm/RIU and a resolvable index change of 2.56×10-4 are obtained experimentally with a ~3.2 µm diameter SPST. The temperature dependence of this fiber optic sensor probe is presented. The proposed SPST refractometer is also significantly less sensitive to temperature and an experimental demonstration of this reduced sensitivity is …


Mechanism Of Multiple Grating Formation In High-Energy Recording Of Holographic Sensors, Ali K. Yetisen, Yunuen Montelongo, Nicholas M. Farandos, Izabela Naydenova, Christopher R. Lowe, Seok Hyun Yun Jan 2014

Mechanism Of Multiple Grating Formation In High-Energy Recording Of Holographic Sensors, Ali K. Yetisen, Yunuen Montelongo, Nicholas M. Farandos, Izabela Naydenova, Christopher R. Lowe, Seok Hyun Yun

Articles

We report numerical analyses of Bragg diffraction by Denisyuk reflection holograms recorded by a high-energy pulsed laser. An intensity threshold must be passed to pattern a multilayer reflection and transmission hologram, which exhibits a nonlinear fringe structure. Numerical evaluations are provided for the laser light intensity, readout diffraction offset angle, transmission of the layer, and thickness of the polymer matrix during hologram recording. A non-sinusoidal surface pattern is formed at the top of the multilayer structure, and its effect on the diffraction properties of the structure becomes significant when the recording tilt angle is increased. Experimental results show that the …


Holographic Sensors: Three-Dimensional Analyte-Sensitive Nanostructures And Their Applications, Ali K. Yetisen, Izabela Naydenova, Fernando Da Cruz Vasconcellos, Jeffrey Blyth, Christopher R. R. Lowe Jan 2014

Holographic Sensors: Three-Dimensional Analyte-Sensitive Nanostructures And Their Applications, Ali K. Yetisen, Izabela Naydenova, Fernando Da Cruz Vasconcellos, Jeffrey Blyth, Christopher R. R. Lowe

Articles

Holographic sensors are analytical devices that systematically diffract narrow-band light in the ultraviolet to near-infrared range for application in the detection and quantification of analytes and/or physical parameters. They can be functionalized with analyte-responsive materials to construct highly sensitive optical sensors for use in testing, where a visual readout, fast turnaround time, and reversibility are needed. Holography allows fabrication of disposable sensors that are lightweight for miniaturization and multiplexing purposes.3 Holographic sensors offer three capabilities on a single analytical device: (i) label-free analyte-responsive polymer, (ii) real-time, reversible quantification of the external stimuli, and (iii) three-dimensional visual image display.