Conventional contact sensors used for Lamb wave-based ultrasonic inspection, such as piezo-electric transducers, measure omnidirectional strain and do not allow distinguishing between fundamental symmetric and anti-symmetric modes. In this paper, we show that the use of a single fibre Bragg grating created in a dedicated microstructured optical fibre allows one to directly make the distinction ...

This paper demonstrates the first single optical fibre tip probe for concurrent detection of both hydrogen peroxide (H₂O₂) concentration and pH of a solution. The sensor is constructed by embedding two fluorophores: carboxyperoxyfluor-1 (CPF1) and seminaphtharhodafluor-2 (SNARF2) within a polymer matrix located on the tip of the optical fibre. The functionalised fibre probe reproducibly measure...

In this paper, we present a non-standard fibre amplifier specially designed to amplify scar modes of a multimode chaotic optical fibre. More precisely, we introduce Ytterbium in the optical fibre as a gain medium localised on the maximum of intensity of the scar modes. After briefly recalling the relevance of a chaotic optical fibre as a device to visualise quantum chaos, we describe the amplif...

Reproducible, precise cleaving of optical fibres is of great importance to the fibre laser and telecommunications industries. We present a novel approach to the end-face processing of optical fibres using a 9.6 µm CO2 laser to produce flat, smooth and symmetric fibre end-face profiles with no rounding or melting at the edges of the fibre. As a demonstration, precision cleaving of a 4...

Photonic sensors signal processors and communication technologies have emerged as viable alternatives to electronics. Fibre optic sensors have advanced to an extent that they can be readily made use of in many applications. The different types of fibre optic sensors, components used in optical fibre sensing, sensor design and analysis, distributed\ multiplexed sensor schemes and the roles of op...

Near-infrared (NIR) and optical polarimetric observations of a selection of X-ray binaries are presented. The targets were observed using the Very Large Telescope and the United Kingdom Infrared Telescope. We detect a significant level (3σ) of linear polarisation in four sources. The polarisation is found to be intrinsic (at the > 3σ level) in two sources; GRO J1655–40 (∼ 4–7% in H and Ks-bands...

is thesis presents results of a research on applications of Brillouin dynamic gratings – distributed reflectors that can be dynamically created in an optical fibre by two optical waves. A basic theory of stimulated Brillouin scattering (SBS) is introduced, on a level enough for understanding the processes that govern SBS. Amajor part of this thesis is dedicated to studies of distributedBrillou...

Optical aberrations have been studied for centuries, placing fundamental limits on the achievable resolution in focusing and imaging. In context of structured light, spatial pattern is distorted amplitude phase, often arising from optical imperfections, element misalignment, or even dynamic processes due to propagation through perturbing media such as living tissue, free-space, underwater fibre...

Optical techniques developed for sensing purposes proved to be essential in many application fields, ranging from aerospace, industry, process control, to security, and also medicine. The capabilities of these sensors are generally enhanced when a bulk-optical configuration is replaced by optical fibre technology. In the past few years, research programmes and also the market for fibre sensors ...