Fibre lasers in the mid-infrared regime are useful for a diverse range of fields, including chemical and biomedical sensing, military applications and materials processing. This Review summarizes the different rare-earth cations and host materials used in mid-infrared fibre laser technology, and discusses the future applications and challenges for the field.

Towards high-power mid-infrared emission from a fibre laser

Raman amplification has enabled dramatic increases in the reach and capacity of lightwave systems. This tutorial explains why, starting with the fundamental properties of gain from stimulated Raman scattering. Next, noise accumulation from amplified spontaneous emission is reviewed, and the merits of distributing Raman gain along a transmission fiber are explained. Other sources of noise that are particularly relevant for Raman amplifiers are summarized. Finally, novel Raman pumping schemes that have recently been developed are highlighted.

https://www.osapublishing.org/viewmedia.cfm?URI=OFC-2003-TuC1&seq=0

Raman amplification for fiber communications systems

http://ieeexplore.ieee.org/iel5/5/31325/01456922.pdf

An introduction to optical waveguides

In this paper, we review the historical evolution of predictions of the performance of optical communication systems. We will describe how such predictions were made from the outset of research in laser based optical communications and how they have evolved to their present form, accurately predicting the performance of coherently detected communication systems.

/pdf/performance-limits-in-optical-communications-due-to-fiber-344tg1jov8.pdf

Performance limits in optical communications due to fiber nonlinearity

This letter describes a model of Raman fiber lasers, based on the four-wave mixing interaction between the laser modes. The results predict the laser spectral shape and output power with good accuracy.

Spectral modeling of Raman fiber lasers

In this letter, we present a technique for calculating the Raman gain spectra of germanosilicate fibers from their index profiles. The gain spectra depend on radial profiles of the guided optical modes and the glass composition, in particular the distribution of Si-O-Si and Ge-O-Si bridging bonds. We have obtained spectral coefficients, which represent the contributions from these bonds using Raman gain measurements made on a set of calibration fibers with well-characterized index profiles. We describe how these spectral coefficients can be used in the design of Raman gain fibers, and we demonstrate the accuracy of our technique over a broad range of fiber types.

A method to predict the Raman gain spectra of germanosilicate fibers with arbitrary index profiles

This paper presents a comprehensive analysis of the temperature dependence of a Raman amplifier and the scaling of the Raman gain coefficient with wavelength, modal overlap, and material composition. The temperature dependence is derived by applying a quantum theoretical description, whereas the scaling of the Raman gain coefficient is derived using a classical electromagnetic model. We also present experimental verification of our theoretical findings.

/pdf/scaling-of-the-raman-gain-coefficient-applications-to-3x4rk454nt.pdf

M.E. Lines

Papers

A method to predict the Raman gain spectra of germanosilicate fibers with arbitrary index profiles

Scaling of the Raman gain coefficient: applications to germanosilicate fibers