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arXiv · 1502.07268

Ab-initio multimode linewidth theory for arbitrary inhomogeneous laser cavities

Adi Pick·Alex Cerjan·David Liu·Alejandro W. Rodriguez·A. Douglas Stone·Yidong D. Chong·Steven G. Johnson
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Abstract

We present a multimode laser-linewidth theory for arbitrary cavity structures and geometries that contains nearly all previously known effects and also finds new nonlinear and multimode corrections, e.g. a bad-cavity correction to the Henry $α$ factor and a multimode Schawlow--Townes relation (each linewidth is proportional to a sum of inverse powers of all lasing modes). Our theory produces a quantitatively accurate formula for the linewidth, with no free parameters, including the full spatial degrees of freedom of the system. Starting with the Maxwell--Bloch equations, we handle quantum and thermal noise by introducing random currents whose correlations are given by the fluctuation--dissipation theorem. We derive coupled-mode equations for the lasing-mode amplitudes and obtain a formula for the linewidths in terms of simple integrals over the steady-state lasing modes.

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Adi Pick, Alex Cerjan, David Liu, Alejandro W. Rodriguez, A. Douglas Stone, Yidong D. Chong, Steven G. Johnson. 2015-05-13. Ab-initio multimode linewidth theory for arbitrary inhomogeneous laser cavities. https://doi.org/10.1103/physreva.91.063806

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