ABSTRACT
A multimode optical fiber with a truncated transverse cross section acts as a powerful versatile support to investigate the wave features of complex ray dynamics. In this paper, we concentrate on the case of a geometry inducing mixed dynamics. We highlight that regular modes associated with stable periodic orbits present an enhanced spatial intensity localization. We report the statistics of the inverse participation ratio whose features are analogous to those of Anderson localized modes. Our study is supported by both numerical and experimental results on the spatial localization and spectral regularity of the regular modes.
ABSTRACT
Wave billiards which are chaotic in the geometrical limit are known to support nongeneric spatially localized modes called scar modes. The interaction of the scar modes with gain has been recently investigated in optics in microcavity lasers and vertical-cavity surface-emitting lasers. Exploiting the localization properties of scar modes in their wave-analogous phase-space representation, we report experimental results of scar mode selection by gain in a doped D-shaped optical fiber.
ABSTRACT
Double-clad fibers with a doped single-mode core and a noncylindrical multimode chaotic cladding are shown to provide optimal pump-power absorption in power amplifiers. Based on the chaotic dynamics of rays in such fibers, we propose a quantitative theory for the pump-absorption ratio and favorably compare the predictions of the theory with numerical results obtained through an adapted beam-propagation scheme.
