Ab-initio multimode linewidth theory for arbitrary inhomogeneous laser cavities

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 $\alpha$ 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.

24 pages, 7 figures

References in corpus (15)

• The physics of exceptional points
• Reversing the Pump-Dependence of a Laser at an Exceptional Point
• Strong Interactions in Multimode Random Lasers
• Supporting Online Material for "Strong Interactions in Multimode Random Lasers"
• Self-consistent multi-mode lasing theory for complex or random lasing media
• Theory of the spatial structure of non-linear lasing modes
• Ab initio self-consistent laser theory and random lasers
• Quantitative Verification of Ab Initio Self-consistent Laser Theory
• Perturbation Theory for Plasmonic Modulation and Sensing
• General linewidth formula for steady-state multimode lasing in arbitrary cavities
• Excess quantum noise due to mode nonorthogonality in dielectric microresonators
• Steady-state ab initio laser theory for complex gain media
• FDTD Simulation of Thermal Noise in Open Cavities
• Spatiotemporal coupled-mode theory in dispersive media under a dynamic modulation
• Generalized Sub-Schawlow-Townes Laser Linewidths Via Material Dispersion

Cited by in corpus (1)

• Symmetry, stability, and computation of degenerate lasing modes