Ultrahigh resolution optical coherence tomography using a superluminescent light source

A superluminescent Ti:Al2O3 crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of ~40 μW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al2O3 crystal. Ultrahigh resolution OCT imaging is demonstrated with 2.2 μm axial resolution in air, or 1.7 μm in tissue, with >86 dB sensitivity. This light source provides a simple and robust alternative to femtosecond lasers for ultrahigh resolution OCT imaging

Characterization of the response of fibre Bragg grating sensors subjected to a two-dimensional strain field

In this paper, the behaviour of fibre Bragg grating sensors subjected to transversal as well as axial strains is characterized, both in the case of low-birefringent and polarization-maintaining single-mode optical fibres. Two configurations are considered. Firstly, diametrical compression is studied and the results compared to those previously obtained in the literature. Secondly, the sensors are embedded in an epoxy specimen and their response monitored when the latter is subjected to biaxial loading. In both cases, the experimental results are compared to those obtained by means of finite-element simulations and an appropriate analytical description of the opto-mechanical response of polarization-maintaining fibres