Numerical modelling of Tb3+ doped selenide-chalcogenide multimode fibre based spontaneous emission sources

A model is developed of a terbium (III) ion doped selenide chalcogenide glass fibre source that provides spontaneous emission within the mid-infrared (MIR) wavelength range. Three numerical algorithms are used to calculate the solution and compare their properties

Modelling of multimode selenide-chalcogenide glass fibre based MIR spontaneous emission sources

Chalcogenide glass fibres have been demonstrated as a suitable medium for the realisation of spontaneous emission sources for mid-infrared photonics applications with a particular emphasis on sensor technology. Such sources give a viable alternative to other solutions due to their potentially low cost, high reliability and robustness when pumped using commercially available semiconductor lasers. We present a comprehensive analysis of the properties of selenide-chalcogenide glass fibres applied as spontaneous emission sources. We extract the modelling parameters from measurements using in house fabricated bulk glass and fibre samples. We apply the well-established rate equations approach to determine the level populations, the distribution of the photon intensity within the fibre and the output power levels. We compare the modelling results with experiment

Broadband, mid-infrared emission from Pr3+ doped GeAsGaSe chalcogenide fiber, optically clad

We present a study of mid-infrared photoluminescence in the wavelength range 3.5–5.5lm emitted from Pr3+: GeAsGaSe core/GeAsGaSe cladding chalcogenide fiber. The Pr3+doped fiber optic preform is fabricated using extrusion and is successfully drawn to low optical loss, step-index fiber. Broadband mid-infrared photoluminescence is observed from the fiber, both under 1.55microns or 1.94 microns wavelength excitation. Absorption, and emission, spectra of bulk glass and fiber are presented. Luminescent lifetimesare measured for the fiber and the Judd–Ofelt parameters are calculated. The radiative transition rates calculated from Judd–Ofelt theory are compared with experimental lifetimes. The observed strong broad-band emission suggests that this type of fiber is a good candidate for further development to realize both fiber lasers and amplified spontaneous emission fiber sources in the mid-infrared region

Construction of Double Cladding Small Dispersion Photonic Crystal Fiber to Guide Ultrashort Pulse at 800 nm

The methods using femtosecond lasers are very popular in the world recently. They are used for different research methods. We begin to use a multi-photon autofluorescence method for cancer tissue detection. We plan to use this method with special photonic crystal fiber optic sensors. We would like to use to this detection femtosecond oscillator for 800 nm region. However, according to our information there is no fiber which can provide these femtosecond signals at 800 nm region without dispersion and nonlinear effect. Applying typical fiber causes dispersion of guided signals. Therefore we are preparing suitably designed fibers. Double-clad photonic fibers can play a dual role of ultrashort pulse delivery and efficient collection of nonlinear optical signals. In the paper a new design of double cladding small dispersion photonic crystal fiber is proposed. Simulations of both structure and dispersion in proposed fibers are presented

A method of measuring moving element displacements in micro-hydraulic valves with the use of optical fibers

This work presents a fiberoptic technique used to measure displacements of moving elements in micro-hydraulic valves. Fiberoptic sensors coupled with a reflection method have proven to be perfect for touchless measurement of movement for elements hard to measure by other methods due to their small size and presence of a hydraulic oil. The article presents results of experiments revealing correlation between the measurement signal and element movement as well as sample displacement changes in time of the moving element in non-equilibrium states – for both, a stable action and self-exciting vibrations of the element

Construction of Double Cladding Small Dispersion Photonic Crystal Fiber to Guide Ultrashort Pulse at 800~nm

The methods using femtosecond lasers are very popular in the world recently. They are used for different research methods. We begin to use a multi-photon autofluorescence method for cancer tissue detection. We plan to use this method with special photonic crystal fiber optic sensors. We would like to use to this detection femtosecond oscillator for 800 nm region. However, according to our information there is no fiber which can provide these femtosecond signals at 800 nm region without dispersion and nonlinear effect. Applying typical fiber causes dispersion of guided signals. Therefore we are preparing suitably designed fibers. Double-clad photonic fibers can play a dual role of ultrashort pulse delivery and efficient collection of nonlinear optical signals. In the paper a new design of double cladding small dispersion photonic crystal fiber is proposed. Simulations of both structure and dispersion in proposed fibers are presented

Intravascular low-power laser illumination through special fiber diffusers

This paper presents the method of intravascular endothelial cell illumination with low-power laser radiation. Some special instruments were prepared, including designed fiber diffusers. The technical parameters of the set-up and the results of arterial system treatment with illumination instruments are presented