Length-dependent static-properties of Nd-doped fibre-lasers: optical feedback effects

摘要

Nd-doped fibre lasers of various lengths have been used in external cavity configurations. The influence of an effective feedback beam" on the static properties of the laser output-intensity shows a clear dependence on fibre-length, owing to gain saturation effects and to residual loss mechanisms other than. resonant absorption (these include Rayleigh diffusion, localized impurities, etc.). A different influence of the back-coupled signal on the forward and backward beams which propagate inside the fibre medium is demonstrated. A simple model based on a standard rate-equation analysis is shown to describe the observed fibre-length-dependent properties.