Mode converter for high power, higher-order mode optical fiber amplifiers

摘要

A mode converter for use with a higher-order mode (HOM)-based fiber amplifiers takes the form of axicon-based configuration that is able to convert high power (tens of mW and higher) optical signals propagating in higher-order mode form into a diffraction-limited beam without experiencing the nonlinear effects (such as self-phase modulation) that are found when using a long-period grating (LPG) to create a diffraction-limited beam by performing mode conversion. The axicon may comprise a bulk optic device, a fiber-based device, or a GRIN-based configuration (where the refractive index profile of the GRIN element is formed to create a diffraction-limited signal).

主权项

1. An optical system for providing conversion of a higher-order mode optical signal into a diffraction-limited beam, the optical system comprising:
an optical waveguide for supporting the propagation of a higher-order mode optical signal; an axicon-based mode converter coupled to the output of the optical waveguide, the axicon-based mode converter including an axicon lensing element and a magnifying element, the magnifying element disposed between the optical waveguide and the axicon lensing element and the axicon lensing element formed to exhibit optical characteristics such that when the higher-order mode optical signal from the optical waveguide is applied as an input to the axicon-based mode converter, the axicon element performs mode conversion in a manner that creates a diffraction-limited output signal.