%0 Journal Article
%T High-Power ZBLAN Glass Fiber Lasers: Review and Prospect
%A Xiushan Zhu
%A N. Peyghambarian
%J Advances in OptoElectronics
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/501956
%X ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF), considered as the most stable heavy metal fluoride glass and the excellent host for rare-earth ions, has been extensively used for efficient and compact ultraviolet, visible, and infrared fiber lasers due to its low intrinsic loss, wide transparency window, and small phonon energy. In this paper, the historical progress and the properties of fluoride glasses and the fabrication of ZBLAN fibers are briefly described. Advances of infrared, upconversion, and supercontinuum ZBLAN fiber lasers are addressed in detail. Finally, constraints on the power scaling of ZBLAN fiber lasers are analyzed and discussed. ZBLAN fiber lasers are showing promise of generating high-power emissions covering from ultraviolet to mid-infrared considering the recent advances in newly designed optical fibers, beam-shaped high-power pump diodes, beam combining techniques, and heat-dissipating technology. 1. Introduction Since the first demonstration of laser emission from a ruby crystal (chromium-doped corundum) in 1960 [1], hundreds of crystals and glasses doped with rare-earth ions have been fabricated and utilized in solid-state lasers to generate coherent emissions at different wavelengths. In contrast to crystals, glasses do not only have broad laser transitions which are essential conditions for wavelength tuning and ultrashort pulses generation but also have broad absorption spectra that relieve the wavelength tolerance for the pump sources. Most importantly, single-mode optical fibers, as the most flexible and compact gain media for high-efficiency and excellent beam-quality laser generation, are mostly drawn from glasses. Although crystalline fibers can be drawn using techniques of edge-defined film-fed growth [2], micropulling-down [3], and laser heated pedestal growth [4], their cores cannot be precisely controlled to be small enough to ensure exclusive single-transverse-mode guiding and their lengths are also technically limited. To date, silicate, phosphate, fluoride, and chalcogenide glasses can be drawn into single-mode fibers. A variety of lasers have also been demonstrated in these glass fibers. The spectral range of glass fiber lasers can cover from ultraviolet (UV) to mid-infrared and the output power of a single-element fiber laser can be up to 6 kilo-watts [5]. In contrast to other lasers, the attractive features of fiber lasers include outstanding heat-dissipating capability, excellent beam quality, high optical conversion efficiency, simplicity and compactness, high single-pass gain, low laser threshold, and broad gain
%U http://www.hindawi.com/journals/aoe/2010/501956/