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Context: Spectral Computed Tomography (SPCT) acquires energy-resolved projections that can be used to evaluate the concentrations of the different materials of an object. This can be achieved by decomposing the projection images in a material basis, in a first step, followed by a standard tomographic reconstruction step. However, material decomposition is a challenging non-linear ill-posed inverse...
The development of high energy short pulse sources at 2 μm wavelength range demonstrates a steady progress during recent years. Real world applications such as medical surgery and polymer micromachining [1] require compact, monolithically integrated all-fibered configurations. While table-top systems deliver outstanding performances on the order of hundreds of μJ and 2 GW peak power in 200 fs compressed...
In order to reduce both acquisition and reconstruction times, illumination and detection in fluorescence molecular tomography have recently evolved from a point-based to a pattern-based approach. However, the choice of the best set of source patterns to project onto the sample is still an open problem. Here, we introduce a novel method, namely the virtual source patterns method, which allows for considering...
In the context of fluorescence diffuse optical tomography, the time-resolved approach was shown to improve the reconstruction quality compared to the continuous-wave approach when adopting the transmittance configuration. However, the improvement seriously decreases in the presence of noise. The scope of this paper is to investigate the additional value of the time-resolved approach in the reflectance...
Nonlinear chirped pulse amplification at high average power and supercontinuum generation are demonstrated in bandgap fibres. A hollow-core fibre is proposed as a host for nonlinear frequency conversion in gas.
We demonstrate the inscription of Bragg gratings in As2S3 optical fibre using a simple Lloyd's interferometer using a mirror with the 532 nm output from a frequency-doubled Nd:YAG laser. Rejection bands > 5dB are produced.
This paper deals with the problem of time-resolved fluorescence diffuse optical tomography. We propose a new reconstruction scheme based on a multi-resolution approximation of the time-resolved signals. The underlying basis functions are exponential B-splines that are matched to the decay of fluorescence signals. We illustrate the applicability of the method on phantom data.
We present a leaky thulium-doped photonic crystal fibre (PCF) design to down shift the thulium emission in the 1.7 - 1.8 mum band. The microstructured cladding structure manages confinement loss to counteract the thulium emission cross section. Thus, the fibre is considered as a distributed low pass filter along the fibre length. Computations on confinement loss show differential loss two orders of...
We experimentally observed the control of the extent of a spectral broadening obtained in a nonlinear photonic bandgap fiber. A spatially singlemode 430 nm-wide spectrum is then obtained by the fiber self-filtering effect.
Highly nonlinear, infrared transmitting lead-bismuth-gallate glass photonic crystal fiber is investigated. Hundred-fold increase in n2 compared to silica and spectral broadening under 1.55 mum ps pumping in 12-cm long PCF are reported.
An original arrangement of air-holes and pure silica is proposed to design ultra broadband fibre couplers. Very high energy transferred superior to 92% on more than 700 nm is demonstrated.
The present paper is devoted to a comparison between time- resolved fluorescence diffuse optical tomography and continuous wave fluorescence diffuse optical tomography. Both of these techniques aim at reconstructing 3D biodistribution of fluorescent markers embedded in biological tissues. The study is restricted in the time domain to the exploitation of the first three temporal moments of measurements...
The present paper is devoted to fluorescence diffuse optical tomography by using time resolved signals for the reconstruction of the 3D biodistribution of fluorescent probes embedded in biological tissues. The focus is made on the reconstruction of a methodology for an efficient exploitation of the time resolved data. The study is restricted to the examination of the three first moments of signals...
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