Bend loss in neodymium-doped fiber lasers

This paper is concerned with the effect of a fixed radius bend upon the operation of a neodymium-doped fiber laser at a wavelength of 1064 nm. In particular, the threshold power, slope efficiency, and cavity lifetime were measured over a range of bend radii and lengths. Oscillations were observed in the variation of the experimentally measured laser parameters with bend length over a range of bend radii which was explained by the finite thickness of the cladding. The results are explained theoretically with the aid of a model in which the pure bend loss coefficient is a parameter in the relevant laser equations and the finite thickness of the cladding is taken into account.