ORCID Profile
0000-0001-7655-514X
Current Organisation
University of Wollongong
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Publisher: The Optical Society
Date: 08-11-2012
DOI: 10.1364/OE.20.026434
Publisher: Springer Science and Business Media LLC
Date: 22-10-2014
Publisher: The Optical Society
Date: 02-04-2013
DOI: 10.1364/OE.21.008605
Publisher: Trans Tech Publications, Ltd.
Date: 07-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.301-303.158
Abstract: This paper introduced an apple quality detection and specie identification system based on multi-spectral imaging. Under an international mixed light illumining, system can capture red, green and infrared images of apples at the same time. A software programmed based on Matlab 6.5.1 is used for image processing to complete the detection of quality and specie. According to processing results, the subtotals and classification are made into grading standards. These can be quickly and easily applied to the automation of agriculture fruit grading system. In the experiment, some most common apples including Fuji apple, Red delicious apples, Green apples, Gina Apple's were detected for quality and variety . Accuracy rate can be more than 90%.
Publisher: Optica Publishing Group
Date: 08-2002
DOI: 10.1364/AO.41.004557
Abstract: The influence of displacement and its first- and second-order derivative components on curvature fringe formations in speckle shearography is discussed. The results show that (a) all the displacement components have no direct influence on curvature fringe formations (b) only the first-order derivative component along the centerline of three apertures has an influence on curvature fringe formations, whereas all the other first-order components have no influence and (c) all the second-order derivative components have no influence on curvature fringe formations. Results from theory and experiments are in good agreement.
Publisher: SPIE
Date: 06-2012
DOI: 10.1117/12.923100
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2012
Publisher: The Optical Society
Date: 17-10-2012
DOI: 10.1364/AO.51.007333
Publisher: Elsevier BV
Date: 02-2014
Publisher: The Optical Society
Date: 09-05-2012
DOI: 10.1364/OE.20.011740
Publisher: IOP Publishing
Date: 07-10-2013
Publisher: SPIE-Intl Soc Optical Eng
Date: 11-09-2014
Publisher: SPIE
Date: 10-01-2005
DOI: 10.1117/12.575150
Publisher: Elsevier BV
Date: 10-2013
Publisher: IOP Publishing
Date: 11-1996
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2007
Publisher: Elsevier BV
Date: 04-2003
Publisher: Elsevier BV
Date: 12-2014
Publisher: Optica Publishing Group
Date: 15-03-2010
DOI: 10.1364/OL.35.000877
Publisher: The Optical Society
Date: 14-04-2011
DOI: 10.1364/OE.19.008285
Publisher: SPIE-Intl Soc Optical Eng
Date: 19-06-2013
Publisher: The Optical Society
Date: 22-06-2017
Publisher: Optica Publishing Group
Date: 2006
DOI: 10.1364/OE.14.007224
Abstract: A high-conversion-efficiency, low-threshold, quasi-continuous-wave optical parametric generator (OPG) based on a periodically poled lithium niobate (PPLN) crystal is presented. Pumped by an acousto-optically Q-switched 1064 nm Nd:YAG laser with a power output of 848 mW, the OPG generated an output power of 452 mW for the signal and the idle waves, achieving an internal conversion efficiency of 62.7% and a slope efficiency of 75.6%. To the best of our knowledge, this is the highest efficiency ever reported for single-pass, quasi-continuous-wave OPGs by using periodically poled crystals.
Publisher: Elsevier BV
Date: 11-2012
Publisher: The Optical Society
Date: 24-09-2013
DOI: 10.1364/OL.38.003850
Publisher: Elsevier BV
Date: 06-2006
Publisher: Elsevier BV
Date: 10-2018
Publisher: IOP Publishing
Date: 05-07-2005
Publisher: Elsevier BV
Date: 02-2003
Publisher: IOP Publishing
Date: 11-10-1999
Publisher: SPIE
Date: 25-10-2017
DOI: 10.1117/12.2285293
Publisher: Optica Publishing Group
Date: 02-12-2008
DOI: 10.1364/OE.16.020817
Abstract: A novel frequency tuning scheme for terahertz-wave parametric oscillators (TPOs) is proposed. We demonstrate that the generation of the tunable terahertz wave can be realized by continuously varying the incident pump wavelength at a fixed angle of incidence of pump relative to the TPO resonator axis, based on the variation of noncollinear phase-matching conditions between the pump and Stokes/THz waves in the process of simulated polariton scattering. Combined with the angle-tuning method, this potential pump-wavelength tuning technique can further extend the TPO tuning range, especially in low-frequency THz region. However, the stability of the output direction of THz waves from the Si prism under this tuning method has yet to be further improved. The characteristics of THz-wave parametric gain involved in this frequency tuning scheme are also studied.
Publisher: Optica Publishing Group
Date: 2005
Abstract: This paper reports a diode-end-pumped continuous-wave (CW) Nd:YAG laser operating at 946-nm by utilizing the 4F3/2-4I9/2 transition. We demonstrated that at an incident pump power of 27.7 W, an output power of 8.3-W could be achieved with a slope efficiency of 33.5%. To the best of our knowledge, this is the highest CW output power at 946 nm generated by LD end-pumped Nd:YAG lasers. By using intracavity frequency doubling with an LBO crystal, we further obtained a 473-nm blue laser with an output power of 1.2 W, achieving an optical-to-optical conversion efficiency of 7.1% at a pump power of 16.9 W. The short-term power instability of the blue laser was less than 1 %.
Publisher: AIP Publishing
Date: 08-05-2006
DOI: 10.1063/1.2202116
Abstract: In this letter, we present a detailed analysis, based on the diffraction of surface acoustic waves, of the relationship between the Bragg bandwidth and the diffraction efficiency in guided acousto-optic interactions. It has been found that the Bragg bandwidth is not always inversely proportional to the acoustic aperture (diffraction efficiency). Therefore, it is possible to simultaneously get high diffraction efficiencies and large bandwidths for a guided acousto-optic device with a single interdigital transducer under certain conditions.
Publisher: Cold Spring Harbor Laboratory
Date: 26-04-2023
DOI: 10.1101/2023.04.23.23289004
Abstract: Abstract. Positron emission tomography (PET) provides quantitative functional imaging of biomarkers unavailable in other modalities, however, images are of relatively low resolution compared to modalities such as magnetic resonance imaging (MRI). A typical approach is to reconstruct to a higher resolution and regularize using a structural image, but there are practical limitations to this approach. Alternatively, post-reconstruction approaches involve image-based correction, but typically rely on a segmentation which may be difficult or even ambiguous to find, depending on the anatomical region or deformities. Here, we perform super-resolution by utilising iterative deconvolution, regularized by minimizing shared directional total variation (dTV) with an anatomical MRI image. We present results on synthetic and clinical data. For the former, PET acquisitions were simulated using an analytic PET simulation. The Gaussian blurring model parameters for deconvolution were optimized on a simplistic phantom simulation with a total variation prior. This model was then applied to deconvolve realistic synthetic data using dTV, which was synthesized to include PET-unique lesions. The model was also applied to a single 18F-florbetaben study acquired over 10 minutes. Gray matter-white matter contrast increased using dTV compared with baseline, however, where an accurate segmentation is available, traditional partial volume correction techniques are superior. Hence, dTV-regularised deconvolution can perform PVC and super-resolution in situations where a reliable segmentation cannot be achieved. With appropriate hyper-parameter selection, dTV deconvolution can preserve PET-unique features.
Publisher: Elsevier BV
Date: 2018
Publisher: Optica Publishing Group
Date: 15-01-2005
DOI: 10.1364/OL.30.000189
Abstract: A novel optical phase-shifting method based on a well-known acousto-optic interaction is proposed. By using a pair of acousto-optic modulators (AOMs) and properly aligning them, we construct an optical phase shifter that can directly control the phase of a collimated beam. The proposed phase shifter is insensitive to the polarization of the incident beam when polarization-insensitive AOMs are used, and no calibration is necessary. The proposed approach is confirmed with experimental results.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2017
Publisher: IEEE
Date: 08-2011
Publisher: Springer Science and Business Media LLC
Date: 05-05-2016
Publisher: Wiley
Date: 17-04-2017
DOI: 10.1002/MP.12209
Abstract: A high resolution, water equivalent, optical and passive x-ray dosimeter has been constructed using plastic scintillator and optical fiber. This dosimeter has a peak edge-on spatial resolution of 100 μm in one dimension, with a 10 μm resolution dosimeter under investigation. The dosimeter design has a potential application in synchrotron x-ray microbeam radiation therapy where a high resolution is vital for accurate dose measurements and quality assurance. BC-400 plastic scintillator, of thickness 100 μm, was optically coupled to an optical fiber with core diameter 1 mm. The end was coated in optical paint to improve sensitivity. An identical fiber was made without the scintillator to measure the background Cherenkov radiation induced in the fiber, to allow background signal subtraction. The light captured by the fibers was measured by PMTs. The probe system was exposed to a 6 MV, 10 × 10 cm The measured profiles matched well with ionisation chamber data. Important beam parameters such as penumbra width and percent depth dose at various depths matched the ionisation chamber data, within uncertainty. This work demonstrates that high resolutions can be achieved with a scintillation and optical fiber system. The probe is water-equivalent, passive, energy independent, radiation hard and inexpensive, making it ideal for further improvements for use with microbeam radiation therapy.
Publisher: Optica Publishing Group
Date: 15-01-2006
DOI: 10.1364/OL.31.000169
Abstract: A practical method for characterizing microstructure fiber lenses in the near field is described. By detecting the optical power of the light reflected by a mirror and coupled back into the single-mode fiber, one can accurately determine the focal point and the working distance of a fiber lens. The approach is relatively simple and easy to implement. The accuracy in determining the focal point and working distance is better than 2%.
Publisher: The Optical Society
Date: 17-01-2013
DOI: 10.1364/OE.21.002003
Publisher: SAGE Publications
Date: 20-07-2016
Abstract: The electrocardiogram (ECG) is an important technique for heart disease diagnosis. This paper proposes a novel method for ECG beat classification. Several important issues exist in the ECG beat classification, which, if suitably addressed, may lead to development of more robust and efficient recognizers. Some of these issues include feature extraction, choice of classification approach and optimization. A new method for non-linear feature extraction of ECG signals based on empirical mode decomposition (EMD), approximate entropy (ApEn) and wavelet packet entropy is presented. The proposed method first uses EMD to decompose ECG signals into a finite number of intrinsic mode functions (IMFs), calculates the ApEn of IMFs as one feature and then obtains the wavelet packet entropy of wavelet packet coefficients as another feature. The two features are regarded as a feature vector. The support vector machine (SVM) and probabilistic neural network (PNN) are used for beat classification. The particle swarm optimization algorithm is used to optimize parameters of the PNN and SVM. The performance of the SVM classifier is slightly superior to that of the PNN classifier with 98.6% accuracy.
Publisher: AIP Publishing
Date: 02-2016
DOI: 10.1063/PT.3.3063
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2008
Publisher: Elsevier BV
Date: 09-1998
Publisher: IEEE
Date: 2005
Publisher: SPIE-Intl Soc Optical Eng
Date: 25-06-2013
Publisher: SPIE-Intl Soc Optical Eng
Date: 07-05-2014
Publisher: The Optical Society
Date: 27-04-2012
DOI: 10.1364/OE.20.011046
Publisher: SPIE
Date: 28-02-2005
DOI: 10.1117/12.582152
Publisher: Optica Publishing Group
Date: 2006
DOI: 10.1364/OE.14.012316
Abstract: In this paper, we introduce a concept of phase matching bandwidth of broadband sources by using the retracing behavior of collinear quasi-phase-matching (CQPM) optical parametric generation (OPG) in periodically poled lithium niobate (PPLN). By comparing various pump wavelengths we derive the pumping condition and parameters of PPLN to realize a broadband source near 1550 nm in the CQPM-OPG. We predict the optimum pump wavelength and the maximum ideal bandwidth range to be 940.75 nm and 1475-1681 nm respectively. Experimentally we have demonstrated a 946 nm Nd:YAG laser which serves as the pumping source of CQPM-OPG.
Publisher: Elsevier BV
Date: 2005
Publisher: SPIE-Intl Soc Optical Eng
Date: 14-09-2018
Publisher: IOP Publishing
Date: 13-12-2006
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/636912
Abstract: Four methods based on a multimode interference (MMI) structure are optimally designed to flatten the spectral response of silicon-on-insulator- (SOI-) based arrayed-waveguide grating (AWG) applied in a demodulation integration microsystem. In the design for each method, SOI is selected as the material, the beam propagation method is used, and the performances (including the 3 dB passband width, the crosstalk, and the insertion loss) of the flat-top AWG are studied. Moreover, the output spectrum responses of AWGs with or without a flattened structure are compared. The results show that low insertion loss, crosstalk, and a flat and efficient spectral response are simultaneously achieved for each kind of structure. By comparing the four designs, the design that combines a tapered MMI with tapered input/output waveguides, which has not been previously reported, was shown to yield better results than others. The optimized design reduced crosstalk to approximately −21.9 dB and had an insertion loss of −4.36 dB and a 3 dB passband width, that is, approximately 65% of the channel spacing.
Publisher: Springer Science and Business Media LLC
Date: 29-09-2017
DOI: 10.1038/S41598-017-12697-6
Abstract: Synchrotron microbeam radiation therapy is a novel external beam therapy under investigation, that uses highly brilliant synchrotron x-rays in microbeams 50 μ m width, with separation of 400 μ m, as implemented here. Due to the fine spatial fractionation dosimetry of these beams is a challenging and complicated problem. In this proof-of-concept work, we present a fibre optic dosimeter that uses plastic scintillator as the radiation conversion material. We claim an ideal one-dimensional resolution of 50 μ m. Using plastic scintillator and fibre optic makes this dosimeter water-equivalent, a very desirable dosimetric property. The dosimeter was tested at the Australian Synchrotron, on the Imaging and Medical Beam-Line. The in idual microbeams were able to be resolved and the peak-to-valley dose ratio and the full width at half maximum of the microbeams was measured. These results are compared to a semiconductor strip detector of the same spatial resolution. A percent depth dose was measured and compared to data acquired by an ionisation chamber. The results presented demonstrate significant steps towards the development of an optical dosimeter with the potential to be applied in quality assurance of microbeam radiation therapy, which is vital if clinical trials are to be performed on human patients.
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.EJMP.2018.10.007
Abstract: The irradiation of scintillator-fiber optic dosimeters by clinical LINACs results in the measurement of scintillation and Cerenkov radiation. In scintillator-fiber optic dosimetry, the scintillation and Cerenkov radiation responses are separated to determine the dose deposited in the scintillator volume. Artificial neural networks (ANNs) were trained and applied in a novel single probe method for the temporal separation of scintillation and Cerenkov radiation. Six dose profiles were measured using the ANN, with the dose profiles compared to those measured using background subtraction and an ionisation chamber. The average dose discrepancy of the ANN measured dose was 2.2% with respect to the ionisation chamber dose and 1.2% with respect to the background subtraction measured dose, while the average dose discrepancy of the background subtraction dose was 1.6% with respect to the ionisation chamber dose. The ANNs performance was degraded when compared with background subtraction, arising from an inaccurate model used to synthesise ANN training data.
Publisher: IOP Publishing
Date: 07-2018
Publisher: IOP Publishing
Date: 07-2008
Publisher: The Optical Society
Date: 09-05-2011
DOI: 10.1364/OL.36.001845
Publisher: IEEE
Date: 2005
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/586517
Abstract: A large-area binary blazed grating coupler for the arrayed waveguide grating (AWG) demodulation integrated microsystem on silicon-on-insulator (SOI) was designed for the first time. Through the coupler, light can be coupled into the SOI waveguide from the InP-based C-band LED for the AWG demodulation integrated microsystem to function. Both the length and width of the grating coupler are 360 μ m, as large as the InP-based C-band LED light emitting area in the system. The coupler was designed and optimized based on the finite difference time domain method. When the incident angle of the light source is 0 ° , the coupling efficiency of the binary blazed grating is 40.92%, and the 3 dB bandwidth is 72 nm at a wavelength of 1550 nm.
Publisher: Wiley
Date: 14-02-2019
DOI: 10.1002/MP.13383
Abstract: The removal of Cherenkov light in an optical dosimetry system is an important process to ensure accurate dosimetry without compromising spatial resolution. Many solutions have been presented in the literature, each with advantages and disadvantages. We present a methodology to remove Cherenkov light from a scintillator fiber optic dosimeter in a pulsed megavoltage x-ray beam using the temporal waveform across the pulse. A s le waveform of Cherenkov light can be measured by exposing only the fiber to the beam. By assuming that the Cherenkov waveform closely matches the intensity of incident radiation, this waveform can be convoluted with the instantaneous scintillation response function to generate an expected scintillation signal. By finding the least-squares fit between these two functions and the experimental data, the estimated Cherenkov contribution can be subtracted off the net signal. This can be applied for arbitrarily complex Cherenkov waveforms (within the 2 ns timing resolution of the data acquisition), and in fact, the results suggest more fluctuations in the waveforms provide a better fit to data. Four beam profiles for different field sizes and energies were found with this method. They closely matched references data measured with ionization chamber with average differences across the beam no more than 4%. Noisy waveforms are assumed to be the primary cause of differences between the analyzed scintillator and IC results. We propose methods for improving the results and optimizing the data acquisition and analysis processes. These results demonstrate that it is possible and effective with a single probe to use function fitting of expected data to experimental to remove a complicated Cherenkov signal from the net light signal in pulsed-beam optical dosimetry.
Publisher: Elsevier BV
Date: 12-2008
Publisher: AIP Publishing
Date: 28-08-2006
DOI: 10.1063/1.2344835
Abstract: A fiber-optic temperature sensor based on the interference of selective higher-order modes in circular optical fibers is described. The authors demonstrate that by coupling the LP01 mode in a standard single-mode fiber to the LP0m modes in a multimode fiber, and utilizing the interference of the higher-order modes, a fiber-optic temperature sensor which has an extremely simple structure and is suitable for high-temperature measurements can be constructed. The sensing principle, temperature measurement experiments, and results are presented.
Publisher: Elsevier BV
Date: 04-2006
Publisher: SPIE
Date: 29-11-2008
DOI: 10.1117/12.757617
Publisher: Optica Publishing Group
Date: 02-2006
DOI: 10.1364/AO.45.000678
Abstract: This paper presents a new approach to fringe pattern profilometry. In this paper, a generalized model describing the relationship between the projected fringe pattern and the deformed fringe pattern is derived, in which the projected fringe pattern can be arbitrary rather than being limited to being sinusoidal, as are those for the conventional approaches. Based on this model, what is believed to be a new approach is proposed to reconstruct the three-dimensional object surface by estimating the shift between the projected and deformed fringe patterns. Additionally, theoretical analysis, computer simulation, and experimental results are presented, which show how the proposed approach can significantly improve the measurement accuracy, especially when the fringe patterns are distorted by unknown factors.
Publisher: Elsevier BV
Date: 04-2007
Publisher: Informa UK Limited
Date: 06-2003
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2015
Publisher: IEEE
Date: 2005
Publisher: IEEE
Date: 2005
Publisher: Shanghai Institute of Optics and Fine Mechanics
Date: 2010
Publisher: Optica Publishing Group
Date: 2005
Abstract: In this paper, we report on a laser fringe projection set-up, which can generate fringe patterns with multiple frequencies and phase shifts. Stationary fringe patterns with sinusoidal intensity distributions are produced by the interference of two laser beams, which are frequency modulated by a pair of acousto-optic modulators (AOMs). The AOMs are driven by two RF signals with the same frequency but a phase delay between them. By changing the RF frequency and the phase delay, the fringe spatial frequency and phase shift can be electronically controlled, which allows high-speed switching from one frequency or phase to another thus makes a dynamic 3D profiling possible.
Publisher: Springer Science and Business Media LLC
Date: 06-05-2014
DOI: 10.1038/SREP04848
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 11-1999
Publisher: SPIE
Date: 13-06-2001
DOI: 10.1117/12.429604
Publisher: The Optical Society
Date: 21-01-2013
DOI: 10.1364/OL.38.000305
Publisher: SPIE
Date: 13-06-2001
DOI: 10.1117/12.429608
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.EJMP.2017.09.134
Abstract: Cherenkov radiation is generated in optical systems exposed to ionising radiation. In water or plastic devices, if the incident radiation has components with high enough energy (for ex le, electrons or positrons with energy greater than 175keV), Cherenkov radiation will be generated. A scintillator dosimeter that collects optical light, guided by optical fibre, will have Cherenkov radiation generated throughout the length of fibre exposed to the radiation field and compromise the signal. We present a novel algorithm to separate Cherenkov radiation signal that requires only a single probe, provided the radiation source is pulsed, such as a linear accelerator in external beam radiation therapy. We use a slow scintillator (BC-444) that, in a constant beam of radiation, reaches peak light output after 1 microsecond, while the Cherenkov signal is detected nearly instantly. This allows our algorithm to separate the scintillator signal from the Cherenkov signal. The relative beam profile and depth dose of a linear accelerator 6MV X-ray field were reconstructed using the algorithm. The optimisation method improved the fit to the ionisation chamber data and improved the reliability of the measurements. The algorithm was able to remove 74% of the Cherenkov light, at the expense of only 1.5% scintillation light. Further characterisation of the Cherenkov radiation signal has the potential to improve the results and allow this method to be used as a simpler optical fibre dosimeter for quality assurance in external beam therapy.
Publisher: Optica Publishing Group
Date: 07-01-2009
DOI: 10.1364/OE.17.000585
Abstract: A theoretical model is established to study the self-similar pulses in nonlinear polarization evolution (NPE) mode-locked fiber lasers. The propagation of pulse in single mode fibers and gain fibers are described by coupled Ginzburg- Landau equation (GLE). Two wave plates and a polarizer are considered to realize the NPE mechanism in simulation. This model describes the laser completely and provides some useful pulses' information. In our simulation the laser generates high quality self-similar pulses output. The region of steady self-similar pulses operation is found. The polarization states of different parts across the pulse are simulated along the laser cavity. It is found that polarization states across the pulse are modulated from elliptical to almost circular before the pulse passing through the polarizer.
Publisher: Elsevier BV
Date: 2016
Publisher: AIP Publishing
Date: 10-03-2008
DOI: 10.1063/1.2895637
Abstract: We present a fiber-optic Fizeau interferometric strain sensor consisting of an in-fiber spherical microcavity of 39μm in diameter. The spherical microcavity was formed by splicing a normal single-mode fiber with a hollow-core photonic crystal fiber. We demonstrate that strain sensing can be realized by using the interference between the light signals reflected by the front and rear surfaces of the sphere. Experiments have shown that the strain sensor has a strain sensitivity of 3.36pm∕με and a temperature sensitivity of 1.35pm∕°C.
Publisher: Elsevier BV
Date: 04-2004
Publisher: SPIE
Date: 09-2006
DOI: 10.1117/12.710731
Publisher: SPIE
Date: 28-02-2005
DOI: 10.1117/12.581484
Publisher: AIP Publishing
Date: 17-07-2023
DOI: 10.1063/5.0157534
Abstract: A waveguide Bragg grating (WBG) can facilitate an adaptable method for glucose monitoring according to the optical properties of polymer materials. We propose the design and fabrication of a WBG for glucose monitoring. By exploiting glucose oxidase as the upper cladding, polydimethylsiloxane was used as the substrate, and polymethyl methacrylate was used as the core layer. We investigated the effects of the diffraction order, waveguide structure, and grating period on the reflected spectrum of the WBG. Finally, process reproducibility after long-term storage and the capability to eliminate background solution interference (to achieve more specific glucose detection) were evaluated. The experimental results showed that when the glucose concentration was in the range of [0, 3.6] mg/ml, as the glucose concentration increased, the wavelength decreased approximately linearly, with a sensitivity of approximately 242.9 pm/(mg/ml) in the range of 0–2.7 mg/ml, while maintaining good selectivity and stability. The WBG for glucose monitoring has the advantages of a large measurement range and high sensitivity. This approach facilitates the application potential of such polymer material-based WBG photonic sensors in wearable technology and realizes the measurement of human blood glucose.
Publisher: Elsevier BV
Date: 2011
Publisher: SPIE
Date: 25-03-2004
DOI: 10.1117/12.523239
Publisher: The Optical Society
Date: 22-03-2011
DOI: 10.1364/OL.36.001122
Publisher: IOP Publishing
Date: 2019
Publisher: SPIE
Date: 24-10-2017
DOI: 10.1117/12.2285522
Publisher: SPIE
Date: 09-11-2005
DOI: 10.1117/12.632582
Publisher: Springer Science and Business Media LLC
Date: 22-11-2011
Publisher: Springer Science and Business Media LLC
Date: 03-05-2019
DOI: 10.1038/S41598-019-43349-6
Abstract: Microbeam radiation therapy is a novel pre-clinical external beam therapy that uses high-brilliance synchrotron X-rays to deliver the necessary high dose rates. The unique conditions of high dose rate and high spatial fractionation demand a new class of detector to experimentally measure important beam quality parameters. Here we demonstrate the highest spatial resolution plastic scintillator fibre-optic dosimeter found in the literature to date and tested it on the Imaging and Medical Beam-Line at the Australian Synchrotron in a X-ray beam where the irradiation dose rate was 4435 Gy/s. With a one-dimensional spatial resolution of 10 μ m the detector is able to resolve the in idual microbeams (53.7 ± 0.4 μ m wide), and measure the peak-to-valley dose ratio to be 55 ± 17. We also investigate the role of radioluminescence in the optical fibre used to transport the scintillation photons, and conclude that it creates a significant contribution to the total light detected.
Publisher: IOP Publishing
Date: 21-07-2006
Publisher: Elsevier BV
Date: 04-2013
Publisher: Springer Science and Business Media LLC
Date: 13-02-2018
Publisher: Optica Publishing Group
Date: 06-2000
DOI: 10.1364/AO.39.002577
Abstract: A five-aperture shearing and two-Fourier filtering technique to measure simultaneously pure curvature and twist distribution fields of a deformed object is proposed. In this method the slope fringes that are contained in the patterns of curvature and twist fringes can be completely eliminated. Thus patterns of pure curvature and twist fringes with a good contrast can be obtained. A theoretical analysis and experimental results are given.
Publisher: IEEE
Date: 08-2011
Publisher: Shanghai Institute of Optics and Fine Mechanics
Date: 2009
Publisher: SPIE
Date: 03-12-2009
DOI: 10.1117/12.806182
Publisher: SPIE-Intl Soc Optical Eng
Date: 13-06-2013
Publisher: IOP Publishing
Date: 09-11-2018
Abstract: Convolutional neural network (CNN) type artificial intelligences were trained to estimate the Cerenkov radiation present in the temporal response of a LINAC irradiated scintillator-fiber optic dosimeter. The CNN estimate of Cerenkov radiation is subtracted from the combined scintillation and Cerenkov radiation temporal response of the irradiated scintillator-fiber optic dosimeter, giving the sole scintillation signal, which is proportional to the scintillator dose. The CNN measured scintillator dose was compared to the background subtraction measured scintillator dose and ionisation chamber measured dose. The dose discrepancy of the CNN measured dose was on average 1.4% with respect to the ionisation chamber measured dose, matching the 1.4% average dose discrepancy of the background subtraction measured dose with respect to the ionisation chamber measured dose. The developed CNNs had an average time of 3 ms to calculate scintillator dose, permitting the CNNs presented to be applicable for dosimetry in real time.
Publisher: Elsevier BV
Date: 10-2021
Publisher: SPIE
Date: 29-11-2008
DOI: 10.1117/12.757318
Publisher: Shanghai Institute of Optics and Fine Mechanics
Date: 2012
Publisher: SPIE
Date: 03-12-2009
DOI: 10.1117/12.806222
Publisher: SPIE
Date: 09-06-2006
DOI: 10.1117/12.693406
Publisher: IEEE
Date: 2005
Publisher: Springer Science and Business Media LLC
Date: 07-07-2016
Publisher: Elsevier BV
Date: 04-2003
Publisher: IEEE
Date: 06-2013
Publisher: IEEE
Date: 2005
Publisher: Elsevier BV
Date: 11-1997
Publisher: SPIE
Date: 03-12-2009
DOI: 10.1117/12.806936
Publisher: SPIE-Intl Soc Optical Eng
Date: 04-12-2012
Publisher: Shanghai Institute of Optics and Fine Mechanics
Date: 2008
Publisher: The Optical Society
Date: 03-2012
DOI: 10.1364/OL.37.000969
Abstract: We report the first (to our knowledge) demonstration of photonic chip based tunable slow and fast light via stimulated Brillouin scattering. Slow, fast, and negative group velocities were observed in a 7 cm long chalcogenide (As(2)S(3)) rib waveguide with a group index change ranging from ~-44 to +130, which results in a maximum delay of ~23 ns at a relatively low gain of ~23 dB. Demonstration of large tunable delays in a chip scale device opens up applications such as frequency sensing and true-time delay for a phased array antenna, where integration and delays ~10 ns are highly desirable.
Publisher: IEEE
Date: 2005
Publisher: IEEE
Date: 2005
Publisher: IOP Publishing
Date: 07-2009
Publisher: Optica Publishing Group
Date: 09-2006
DOI: 10.1364/AO.45.006560
Abstract: What is believed to be a new analysis algorithm to carry out profile measurement with low computational complexity and less noise sensitivity is presented. First, a discrete cosine transform (DCT)-based representation method is introduced to express the height distribution of a 3D surface. Then a novel shift estimation algorithm, called the DCT-based shift estimation (DCT-SE), is presented to reconstruct 3D object surfaces by using the proposed expression and the generalized analysis model. The advantage of DCT-SE is that without loss of measurement precision it provides lower computational complexity to implement 3D reconstruction from nonlinearly distorted fringe patterns and, at the same time, survives the random noise. Simulations and experiments show that the proposed DCT-SE is a fast, accurate, and efficient reconstruction algorithm for digital projection- based fringe pattern profilometry techniques.
Publisher: IOP Publishing
Date: 16-03-2012
Publisher: Elsevier BV
Date: 2001
Publisher: SPIE
Date: 24-11-2005
DOI: 10.1117/12.634919
Publisher: Springer Science and Business Media LLC
Date: 30-01-2014
DOI: 10.1038/NCOMMS4225
Publisher: Elsevier BV
Date: 06-2006
Publisher: IOP Publishing
Date: 28-08-2007
Publisher: AIP Publishing
Date: 09-06-2008
DOI: 10.1063/1.2945275
Abstract: We present in this letter the fabrication and characterization of thermally stable type II waveguides in Z-cut periodically poled lithium niobate crystals. The waveguides were fabricated by using a femtosecond laser and were utilized for second harmonic generation. Our experiments have shown that a quasiphase matching wavelength of 1548.2nm, a tuning bandwidth of 2nm, and a tuning temperature range of 150.4±1.6°C can be achieved.
Publisher: Elsevier BV
Date: 2000
Publisher: The Optical Society
Date: 08-2012
DOI: 10.1364/OE.20.018836
Publisher: SPIE
Date: 08-09-2011
DOI: 10.1117/12.894515
Publisher: SPIE-Intl Soc Optical Eng
Date: 27-06-2018
Publisher: SPIE
Date: 06-2012
DOI: 10.1117/12.922140
Publisher: Astro, Ltd.
Date: 12-2012
Publisher: SAGE Publications
Date: 20-07-2017
Abstract: In most traditional electrocardiogram (ECG) detection procedures, wet electrodes must be glued to the skin during the procedure and may cause problems such as inconvenience and skin irritation. Furthermore, the quality of the acquired signals decreases because the glue dehydrates over time. In this study, a non-contact ECG acquisition system based on capacitive coupling textile electrodes with low-power consumption and high input impedance is presented. We designed electrodes that have a composite and textile structure. A kind of conductive textile with stainless steel wire creates these electrodes. We wove the conductive textile that has good electrical conductivity with a surface resistivity of 1.25 Ω/sq. Both circuit models of the skin–electrode interface and lifier for the capacitively coupled textile electrode were established, and the output signal-to-noise ratio (SNR) of the front-end circuit was proposed. The integrated system combines lification, filter circuit and analogue-to-digital converter. The final measurement shows that the ECG signals acquired by our system are adequate for heartbeat detection and applicable to clinical practice.
Publisher: International Union of Crystallography (IUCr)
Date: 24-04-2018
DOI: 10.1107/S1600577518003016
Abstract: Cancer is one of the leading causes of death worldwide. External beam radiation therapy is one of the most important modalities for the treatment of cancers. Synchrotron microbeam radiation therapy (MRT) is a novel pre-clinical therapy that uses highly spatially fractionated X-ray beams to target tumours, allowing doses much higher than conventional radiotherapies to be delivered. A dosimeter with a high spatial resolution is required to provide the appropriate quality assurance for MRT. This work presents a plastic scintillator fibre optic dosimeter with a one-dimensional spatial resolution of 20 µm, an improvement on the dosimeter with a resolution of 50 µm that was demonstrated in previous work. The ability of this probe to resolve microbeams of width 50 µm has been demonstrated. The major limitations of this method were identified, most notably the low-light signal resulting from the small sensitive volume, which made valley dose measurements very challenging. A titanium-based reflective paint was used as a coating on the probe to improve the light collection, but a possible effect of the high- Z material on the probes water-equivalence has been identified. The effect of the reflective paint was a 28.5 ± 4.6% increase in the total light collected it did not affect the shape of the depth-dose profile, nor did it explain an over-response observed when used to probe at low depths, when compared with an ionization chamber. With improvements to the data acquisition, this probe design has the potential to provide a water-equivalent, inexpensive dosimetry tool for MRT.
Publisher: The Optical Society
Date: 15-09-2011
DOI: 10.1364/OL.36.003687
Publisher: SPIE
Date: 14-02-2004
DOI: 10.1117/12.575204
Publisher: Elsevier BV
Date: 06-0005
Publisher: SPIE
Date: 20-01-2004
DOI: 10.1117/12.574593
Publisher: IOP Publishing
Date: 2019
Publisher: SPIE
Date: 10-02-2005
DOI: 10.1117/12.572213
Publisher: The Optical Society
Date: 06-09-2016
DOI: 10.1364/OL.41.004158
Publisher: Optica Publishing Group
Date: 08-2005
DOI: 10.1364/OL.30.001965
Abstract: We report a new method of sensing a three-dimensional (3D) object surface with an arbitrary geometric shape. In this approach, the first-order beams diffracted from two acousto-optic deflectors (AODs) interfere with each other to form a spatial carrier that is used to encode the depth information from the 3D object surface. A direct digital synthesizer is utilized to control two AODs to generate sequentially spatial carriers with different spatial frequencies so that a modified temporal phase-unwrapping technique can be applied for decoding the shape information of the test surface. Preliminary experimental results are presented to demonstrate the effectiveness of this method.
Publisher: Optica Publishing Group
Date: 15-06-2006
DOI: 10.1364/OL.31.001869
Abstract: A high-power continuous-wave (cw) Nd:YAG laser operating at 946 nm by utilizing a quasi-three-level transition is reported. The laser consists of a composite Nd:YAG rod end pumped by a fiber-coupled diode laser and a simple plane-concave cavity. At an incident pump power of 40.2 W, a maximum cw output of 15.2 W at 946 nm is obtained, achieving a slope efficiency of 45%. To the best of our knowledge, this is the highest output at 946 nm ever generated by diode-pumped Nd:YAG lasers. In addition, at an incident pump power of 15.2 W, a 1.25 W blue output at 473 nm is achieved with a simple compact three-element cavity and a type-I lithium triborate (LiB(3)O(5)) crystal as a frequency doubler.
Publisher: SPIE
Date: 03-12-2009
DOI: 10.1117/12.812007
Publisher: SPIE
Date: 03-12-2009
DOI: 10.1117/12.812009
Publisher: IOP Publishing
Date: 02-02-2007
Publisher: Springer Science and Business Media LLC
Date: 24-07-2011
Publisher: No publisher found
Date: 2000
DOI: 10.1117/1.1305459
Publisher: The Royal Society
Date: 04-2018
DOI: 10.1098/RSOS.172447
Abstract: Photons are weak particles that do not directly couple to magnetic fields. However, it is possible to generate a photonic gauge field by breaking reciprocity such that the phase of light depends on its direction of propagation. This non-reciprocal phase indicates the presence of an effective magnetic field for the light itself. By suitable tailoring of this phase, it is possible to demonstrate quantum effects typically associated with electrons, and, as has been recently shown, non-trivial topological properties of light. This paper reviews dynamic modulation as a process for breaking the time-reversal symmetry of light and generating a synthetic gauge field, and discusses its role in topological photonics, as well as recent developments in exploring topological photonics in higher dimensions.
Publisher: SPIE
Date: 09-06-2006
DOI: 10.1117/12.694434
Publisher: Optica Publishing Group
Date: 13-07-2007
DOI: 10.1364/OL.32.002064
Abstract: Single-mode-multimode-single-mode (SMS) fiber structures have been demonstrated to be a simple and effective way to realize multimode interference (MMI) in optical fibers. The temperature dependence of the spectral characteristics of SMS devices is investigated. By utilizing the feature that the response spectra of SMS devices with opposite polarities to temperature and axial tensile strain, I demonstrate that temperature compensation of SMS devices can be realized by using materials with a proper coefficient of thermal expansion. A temperature stability of 1.0 pm/ degrees C has been experimentally demonstrated with a ceramic as the packaging material.
Publisher: IEEE
Date: 07-2011
Publisher: Optica Publishing Group
Date: 17-05-2010
DOI: 10.1364/OL.35.001752
Publisher: Elsevier BV
Date: 07-1997
No related grants have been discovered for Enbang Li.