Random distributed feedback fibre laser

• Published in: Nature photonics Vol. 4; no. 4; pp. 231 - 235
• Main Authors: Turitsyn, Sergei K, Babin, Sergey A, El-Taher, Atalla E, Harper, Paul, Churkin, Dmitriy V, Kablukov, Sergey I, Ania-Castañón, Juan Diego, Karalekas, Vassilis, Podivilov, Evgenii V
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-04-2010; Nature Publishing Group
• Subjects: 639/624/1020/1086; Amplification; Applied and Technical Physics; Beams (radiation); Coherent light; Feedback; Fibre; Inhomogeneities; Lasers; Physics; Physics and Astronomy; Quantum Physics; Rayleigh scattering
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2010.4

The concept of random lasers making use of multiple scattering in amplifying disordered media to generate coherent light has attracted a great deal of attention in recent years. Here, we demonstrate a fibre laser with a mirrorless open cavity that operates via Rayleigh scattering, amplified through the Raman effect. The fibre waveguide geometry provides transverse confinement and effectively one-dimensional random distributed feedback, leading to the generation of a stationary near-Gaussian beam with a narrow spectrum, and with efficiency and performance comparable to regular lasers. Rayleigh scattering due to inhomogeneities within the glass structure of the fibre is extremely weak, making the operation and properties of the proposed random distributed feedback lasers profoundly different from those of both traditional random lasers and conventional fibre lasers.
The combination of distributed Rayleigh back-scatter and Raman gain in an optical fibre yields an open cavity, mirror-less fibre laser that offers stable operation at the telecommunications wavelength of 1.5 µm.