The historical beginnings of photosensitivity and fiber Bragg grating (FBG) technology are recounted. The basic techniques for fiber grating fabrication, their characteristics, and the fundamental properties of fiber gratings are described. The many applications of fiber grating technology are tabulated, and some selected applications are briefly described.

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Fiber Bragg grating technology fundamentals and overview

This Review summarizes the simultaneous transmission of several independent spatial channels of light along optical fibres to expand the data-carrying capacity of optical communications. Recent results achieved in both multicore and multimode optical fibres are documented.

/pdf/space-division-multiplexing-in-optical-fibres-9acl86j916.pdf

Space-division multiplexing in optical fibres

Femtosecond laser micromachining can be used either to remove materials or to change a material's properties, and can be applied to both absorptive and transparent substances. Over the past decade, this technique has been used in a broad range of applications, from waveguide fabrication to cell ablation. This review describes the physical mechanisms and the main experimental parameters involved in the femtosecond laser micromachining of transparent materials, and important emerging applications of the technology. Interactions between laser and matter are fascinating and have found a wide range of applications. This article gives an overview of the fundamental physical mechanisms in the processing of transparent materials using ultrafast lasers, as well as important emerging applications of the technology.

Femtosecond laser micromachining in transparent materials

The history, fabrication, theory, numerical modeling, optical properties, guidance mechanisms, and applications of photonic-crystal fibers are reviewed

Photonic-Crystal Fibers

Recent research on fibre optic long-period gratings (LPGs) is reviewed with emphasis placed upon the characteristics of LPGs that make them attractive for applications in sensing strain, temperature, bend radius and external index of refraction. The prospect of the development of multi-parameter sensors, capable of simultaneously monitoring a number of these measurands will be discussed.

https://iopscience.iop.org/article/10.1088/0957-0233/14/5/201/pdf

Optical fibre long-period grating sensors: characteristics and application

A comprehensive survey of photosensitivity in silica glasses and optical fiber is reviewed Recent work on understanding the mechanisms contributing to germanium or aluminum doped fiber photosensitivity is discussed within the framework of photoelastic densification models

Densification involved in the UV-based photosensitivity of silica glasses and optical fibers

The fabrication and characterization of an all-solid photonic bandgap fiber is reported. The fiber presents a low-loss region (< 20 dB/km) around 1550 nm and can be used as single-mode even for a fiber core diameter as large as 20 μm. The fiber presents a zero dispersion at the short wavelength edge of the bandgap. The measured polarisation mode dispersion is wavelength dependent but remains small (few ps/km1/2). This fiber opens the possibility to realize low-loss large mode area bandgap fiber with a doped core and or Bragg gratings.

Fabrication and characterization of an all-solid 2D photonic bandgap fiber with a low-loss region (< 20 dB/km) around 1550 nm.

In the present letter the authors report on the realization of an all-fiber bismuth-doped laser with laser emission that can be chosen with corresponding fiber Bragg gratings between at least 1150 and 1225 nm . In their experiments they achieved a slope efficiency of about 24% at 1200 nm , which is the highest reported for this kind of laser.

Efficient all-fiber bismuth-doped laser

We study experimentally and numerically the temporal features of supercontinuum generated with a continuous-wave ytterbium-doped fiber laser. We show that the temporal output of the supercontinuum is characterized by strong and brief power fluctuations, i.e. so-called optical rogue waves. We demonstrate numerically that these rare and strong events that appear and disappear from nowhere result from solitonic collisions.

Observation of extreme temporal events in CW-pumped supercontinuum

In the present work, we report on the luminescence properties of bismuth-doped silicate preforms and fibers under the influence of high temperature annealing and hydrogen-loading then annealing processes. Bismuth-related luminescence is found to be very sensitive to thermal annealing processes and can even totally disappear for specific annealing processes. The observed quenching of the luminescence was attributed to the reduction of part of bismuth ions responsible for the infrared luminescence into a lower valence state of bismuth.

Marc Douay

Papers

Densification involved in the UV-based photosensitivity of silica glasses and optical fibers

Fabrication and characterization of an all-solid 2D photonic bandgap fiber with a low-loss region (< 20 dB/km) around 1550 nm.

Efficient all-fiber bismuth-doped laser

Observation of extreme temporal events in CW-pumped supercontinuum

Study of thermal stability and luminescence quenching properties of bismuth-doped silicate glasses for fiber laser applications