Prebifurcation noise amplification in a fiber laser

Abstract

We report on the experimental evidence of noise amplification in an erbium-doped fiber laser in the vicinity of saddle-node, period-doubling, and crisis bifurcations. We demonstrate this interesting phenomenon by analyzing the laser bifurcation diagrams and power spectra. Numerical simulations on the base of an advanced laser model display good agreement with the experimental results.

The use of nonlinear dynamics of erbium-doped fiber laser at pump modulation for intra-cavity sensing

“…This value is much less than instabilities of the two adjacent pulsed regimes (see also Ref. [34]). Actually, the high stability of the period-1 regime determines one of the main advantages of the proposed EDFL-based sensor, its superior sensitivity.…”

“…(1),(2) [21,34], to allow the reader to make a direct comparison between the experimental data (see above) and modeling results (notice that all the parameters' values used in the modeling are explicitly the same as in the experiments). So, we have adjusted the model [21,34] to the circumstance where an EDFL is used as an intra-cavity loss sensor, operation of which is essentially the period-1 pulsed regime. [Remind that in Ref.…”

“…Pump power modulation can be accounted in a manner similar to the approach described in Ref. [34]. Being an ''external'' periodic force, pump modulation turns the EDFL to one of the nonlinear dynamics regimes, e.g.…”

“…The balance equations for the EDFL intra-cavity generation power P g (s À 1 ) and dimensionless population y of the upper laser level (Er 3 + : 4 I 13/2 ) can be written as [34] …”

“…[21] we inspected an EDFL-based sensor without external modulation, whereas in Ref. [34] we investigated the general dynamics features of an EDFL at pump modulation due to the noise effects. ]…”