ORCID Profile
0000-0002-2543-2374
Current Organisations
The University of Adelaide Adelaide SA AU
,
University of South Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Springer Singapore
Date: 24-09-2018
Publisher: Optica Publishing Group
Date: 15-03-2022
DOI: 10.1364/OE.443932
Abstract: Fiber specklegram sensors (FSSs) traditionally use statistical methods to analyze specklegrams obtained from fibers for sensing purposes, but can suffer from limitations such as vulnerability to noise and lack of dynamic range. In this paper we demonstrate that deep learning improves the analysis of specklegrams for sensing, which we show here for both air temperature and water immersion length measurements. Two deep neural networks (DNNs) a convolutional neural network and a multi-layer perceptron network, are used and compared to a traditional correlation technique on data obtained from a multimode fiber exposed-core fiber. The ability for the DNNs to be trained against a random noise source such as specklegram translations is also demonstrated.
Publisher: AIP Publishing
Date: 02-2021
DOI: 10.1063/5.0036300
Abstract: The tracking of small particles is an important but challenging task for biological applications such as disease diagnostics and medical research. Current methods are limited to the use of bulky instruments such as flow cytometers and microscopes. Here, a novel technique for the detection and measurement of micron-scale optical scatterers using a few-mode exposed-core microstructured optical fiber is proposed. Through selective mode launching combined with optical frequency domain reflectometry, scatterers located on the fiber core surface can be simultaneously mapped with both longitudinal and transverse information. This technique is demonstrated by detecting the two-dimensional positions of several femtosecond-laser-inscribed micron-scale ablations written at different locations on the fiber core surface. Due to the compact nature of the optical fiber and its local sensitivity to scatterers that are in close proximity to it, this technique has the potential for the measurement and detection of micron-scale particles in difficult to reach biological environments for in vivo applications.
Publisher: Elsevier BV
Date: 11-2023
Publisher: SPIE
Date: 14-04-2008
DOI: 10.1117/12.786061
Publisher: SPIE
Date: 29-04-2016
DOI: 10.1117/12.2227354
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 12-2008
Publisher: IOP Publishing
Date: 04-02-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-02-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-04-2019
Publisher: Optica Publishing Group
Date: 14-07-2008
DOI: 10.1364/OE.16.011369
Abstract: We report a simple fiber sensor for measurement of high temperature with high sensitivity. The sensing head is a multimode-single mode-multimode (MM-SM-MM) fiber configuration formed by splicing a section of uncoated single mode fiber (SMF) with two short sections of multimode fibers (MMF) whose core is composed of pure silica. Because of the mode-field mismatch at the splicing points of the SMF with 2 sections of MMFs, as well as index matching between the core of the MMF and the cladding of the SMF, optical power from the lead-in fiber can be partly coupled to the cladding modes of the SMF through the MMF. The cladding modes of the SMF then re-coupled to the lead-out fiber, in the same fashion. Due to the effective index difference between the core and cladding modes, an interference pattern in the transmission spectrum of the proposed device was obtained. The interference pattern was found to shift to the longer wavelength region with respect to temperature variation. The temperature sensor can measure temperature stably up to more than 900 degrees C with sensitivity of 0.088 nm/ degrees C.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Wiley
Date: 21-07-2015
DOI: 10.1111/IJAG.12128
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2020
Publisher: IOP Publishing
Date: 12-03-2021
Abstract: An analysis is provided of fiber-optic Fabry–Perot interferometers designed and fabricated using collimating graded-index fiber (GIF) tips as an alternative to typical highly ergent standard single-mode fibers (SMFs). The collimated beam from the GIF tips allows for significantly longer etalons to be fabricated due to the increased collection efficiency when used either in reflection or transmission mode. We extend previous results, showing that GIF tips using coreless fiber segments can allow for up to four-fold increase in fringe visibility (FV) at 1550 nm compared with standard SMF Fabry–Perot etalons of the same length. The collimating GIF tips help lessen the FV vs cavity length trade-off typically observed in fiber-optic Fabry–Perot systems. We also explore the effects on FV improvement when using capillaries to align the fibres. This paper also provides easily accessible design guidelines and considerations for fabricating GIF based devices at 1550 nm.
Publisher: IOP Publishing
Date: 04-02-2009
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2541105
Publisher: Optica Publishing Group
Date: 2022
DOI: 10.1364/CLEOPR.2022.CTUP1C_02
Abstract: Stimulated Brillouin scattering (SBS) induced by narrow-linewidth high power pulses in a multimode fiber (MMF) is suppressed via controlling the input wavefront, presenting a new route to scaling power in high power fiber lifiers.
Publisher: The Optical Society
Date: 18-12-2012
DOI: 10.1364/OE.20.029378
Publisher: SPIE
Date: 05-10-2009
DOI: 10.1117/12.834075
Publisher: The Optical Society
Date: 18-11-2014
DOI: 10.1364/OE.22.029493
Publisher: Optica Publishing Group
Date: 22-07-2020
DOI: 10.1364/OE.397537
Abstract: Femtosecond laser inscribed fiber Bragg gratings in pure-silica suspended-core optical fibers have previously been demonstrated as a promising platform for high temperature sensing. However, the density of gratings that could be written on a single fiber was limited by undesired reflections associated with higher order modes in these high numerical aperture fibers. This resulted in a complex, broadband reflection spectrum with limited multiplexing capability. In this work we utilize modifications to the fine structure of the suspended core optical fibers to fine tune the relative confinement loss of the optical fiber modes, thus reducing the contribution from such higher order modes. The effects of these changes on mode propagation are modeled, giving a range of fibers with different confinement loss properties which can be tailored to the specific length scale of a desired application. We achieve single-peak reflections from in idual fiber Bragg gratings, significantly improving performance for multipoint sensing and demonstrate this technique by writing 20 gratings onto a single fiber.
Publisher: The Optical Society
Date: 14-04-2016
DOI: 10.1364/OE.24.008967
Publisher: Optica Publishing Group
Date: 26-03-2021
DOI: 10.1364/PRJ.415902
Abstract: A new approach to optical fiber sensing is proposed and demonstrated that allows for specific measurement even in the presence of strong noise from undesired environmental perturbations. A deep neural network model is trained to statistically learn the relation of the complex optical interference output from a multimode optical fiber (MMF) with respect to a measurand of interest while discriminating the noise. This technique negates the need to carefully shield against, or compensate for, undesired perturbations, as is often the case for traditional optical fiber sensors. This is achieved entirely in software without any fiber postprocessing fabrication steps or specific packaging required, such as fiber Bragg gratings or specialized coatings. The technique is highly generalizable, whereby the model can be trained to identify any measurand of interest within any noisy environment provided the measurand affects the optical path length of the MMF’s guided modes. We demonstrate the approach using a sapphire crystal optical fiber for temperature sensing under strong noise induced by mechanical vibrations, showing the power of the technique not only to extract sensing information buried in strong noise but to also enable sensing using traditionally challenging exotic materials.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: The Optical Society
Date: 12-02-2016
DOI: 10.1364/OE.24.003714
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2023
Publisher: Elsevier BV
Date: 03-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2019
Publisher: AIP Publishing
Date: 19-10-2009
DOI: 10.1063/1.3233971
Abstract: We report all-optical signal gating using ytterbium-doped fiber (YDF) and a pair of thermally expanded core fibers (TECFs). Splicing the YDF with two TECFs at their expanded-core ends, we obtained an interference pattern in the transmission spectrum of the device. When pumped by a laser diode at 980 nm, the interference fringes shift to longer wavelength due mainly to the resonantly enhanced nonlinearity of the YDF. Consequently, signals within the interference pattern can be gated or blocked all optically. Full gating of cw signals at 1564.21 and 1564.54 nm were obtained using a pump power of about 38.44 mW.
Publisher: SPIE
Date: 23-04-2017
DOI: 10.1117/12.2265205
Publisher: SPIE
Date: 02-06-2014
DOI: 10.1117/12.2059155
Publisher: SPIE
Date: 17-10-2012
DOI: 10.1117/12.966847
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3AN01047C
Abstract: Isothermal lification technology has trigged a surge in research due to its compatibility with small and portable equipment, simplicity, and high efficiency, especially in light of the COVID-19 pandemic where...
Publisher: Optica Publishing Group
Date: 09-05-2022
DOI: 10.1364/OL.456552
Abstract: In this paper, a highly sensitive temperature compensated fiber optic magnetic field sensor by Sagnac and Mach–Zehnder combination interference (SMZI) is proposed and verified. The sensing structure relies on microstructured exposed core fiber (ECF) filled with ethanol and magnetic fluid (MF). The refractive index of MF and ethanol is affected by the magnetic field and temperature (MFT). SMZI is based on the multimode and birefringence characteristics of ECF. The measurement principle is that the spectra of Sagnac interference and Mach–Zehnder interference have respective sensitivities to the MFT. The magnetic sensitivity can reach 1.17 nm/mT, and the temperature sensitivity is up to –1.93 nm/°C. At the same time, the sensor has good repeatability and low detection limits of 0.41 mT and 0.25°C, respectively. It not only solves the cross-influence of temperature but also makes the spectral analysis more intuitive. The sensor has a broad development prospect in the application of MFT detection.
Publisher: Optica Publishing Group
Date: 2022
DOI: 10.1364/CLEOPR.2022.CTHA10C_01
Abstract: We numerically and experimentally demonstrate that spreading power into higher order modes of a multimode optical fiber can be used to suppress stimulated Brillouin scattering for a high-power narrow linewidth system. This opens the opportunity for suppressing nonlinear effects in fibers using adaptive mode launching techniques while retaining the ability to produce spatially coherent beams through control of the light phase.
Publisher: SPIE
Date: 14-04-2008
DOI: 10.1117/12.786077
Publisher: Elsevier BV
Date: 2022
Publisher: IEEE
Date: 10-2018
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 2022
Publisher: Optica Publishing Group
Date: 09-07-2021
DOI: 10.1364/OE.431544
Abstract: Whispering gallery modes (WGMs) in micro-resonators are of interest due to their high Q-factors. Ultra-thin fiber tapers are widely deployed to couple light into micro-resonators but achieving stable and practical coupling for out-of-lab use remains challenging. Here, a new WGM coupling scheme using an exposed-core silica fiber (ECF) is proposed, which overcomes the challenge of using fragile fiber tapers. Microspheres are deposited onto the exposed channel for excitation via the evanescent field of the fiber’s guided modes. The outer jacket of the ECF partially encapsulates the microspheres, protecting them from external physical disturbance. By varying the mode launching conditions in this few-mode ECF, in combination with a Fano resonance effect, we demonstrate a high degree of tunability in the reflection spectrum. Furthermore, we show multi-particle WGM excitation, which could be controlled to occur either simultaneously or separately through controlling the ECF mode launching conditions. This work can bring value towards applications such as optical switches and modulators, multiplexed/distributed biosensing, and multi-point lasing, integrated in a single optical fiber device that avoids fiber post-processing.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-11-2019
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2541295
Publisher: Optica Publishing Group
Date: 2022
DOI: 10.1364/CLEOPR.2022.CWP17B_02
Abstract: We report a specklegram pressure sensor using a pure silica six-hole novel microstructured optical fiber. This simple and low-cost sensor has the potential for pressure measurement at high temperature harsh environment applications.
Publisher: MDPI AG
Date: 08-08-2014
DOI: 10.3390/S140814488
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-06-2020
Publisher: American Chemical Society (ACS)
Date: 22-07-2021
No related grants have been discovered for Linh Nguyen.