Efficient coherent combining of tunable erbium-doped fibre ring lasers

Model for passive coherent beam combining in fiber laser arrays

We present a new model for studying the beam combining mechanism, spectral and temporal dynamics, the role of nonlinearity, and the power scaling issue of discretely coupled fiber laser arrays. The model accounts for the multiple longitudinal modes of individual fiber lasers and shows directly the formation of the composite-cavity modes. Detailed output power spectra and their evolution with increasing array size and pump power are also explored for the first time. In addition, it is, to our knowledge, the only model that closely resembles the real experimental conditions in which no deliberate control of the fiber lengths (mismatch) is required while highly efficient coherent beam combining is still attained.

Self-organization of arrays of two mutually-injected fiber lasers: theoretical investigation

The array of two mutually-injected fiber lasers is theoretically studied. It is found that the self-organization mechanism of this array is virtually the longitudinal-mode competition in the compound laser cavity. Two phase-locked states of this array are predicted. The performance of this array is also investigated, and the theoretical result agrees well with the experimental observation. Based on the theoretical analysis, some advices for building this array are also given.

Dynamical model for self-organized fiber laser arrays

A dynamics model of self-organized fiber laser arrays is presented in this paper. The model does not only break the limitation of the standard slowly varying wave approximation, but also be built on the basis of Maxwell-Bloch equations which make this model more suitable to study the dynamics (especially phase dynamics) of fiber laser arrays. In this paper, this model is applied to analyze fiber laser array of interferometric configuration. The results agree well with the reported experimental results. It is also revealed that the coupling strength of 2-fiber laser array of interferometric configuration have a negligible effect on the phase-locked state of the array.

Effect of polarization controlling on coherent beam combining of two-fiber laser arrays of interferometric configuration

The effect of polarization controlling on coherent beam combining of two-fiber laser arrays of interferometric configuration is researched. Three kinds of arrays, built on the basis of Michelson and Mach-Zehnder interferometers, are investigated experimentally. It is found that polarization controlling is not necessary for coherent beam combining of the Michelson interferometric array but necessary for that of Mach-Zehnder interferometric arrays. These results reveal the important role of polarization in the self-organization process of interferometric laser arrays.