Polaroid Corporation

Lucent Technologies Inc.

Martin H Muendel

Stephen G Grubb

Thomas Andrew Strasser

Clifford E Headley

Bennett H Rockney

John R Lewis

Janet Renee Pedrazzani

Applicants have discovered that the intermodal beat noise of a fiber multimode laser can be substantially reduced by providing the fiber with an output coupler of broadened bandwidth. In a preferred embodiment, a reduced-noise, high power light source comprises a cladding pumped fiber laser having a chirped output grating. Experiments show that increasing the output bandwidth from 0.254 to 0.577 nm reduces the relative intensity-to-noise ratio 10 dB in a Nd-doped fiber laser. Increasing the bandwidth from 0.2 nm to 0.3 nm in a Yb-doped laser similarly reduces the noise by 12 dB.

Fiber multimode laser with reduced noise

An optical fiber structure for use in gain applications which comprises a core, selectively doped with an active gain species, and an inner cladding surrounding the core, where the inner cladding serves the purpose of receiving multimode pump energy from an external power source, confining this energy, and transferring the energy into the core by means of repeated interactions between the energy and the active dopant within the core as the pump energy propagates along the length of the fiber structure. The cross-sectional shape of the inner cladding is in the form of a non-rectangular, convex polygon so that the propagating pump energy is induced to form an essentially uniform radiation field in which the various radiation modes comprising the pump energy are isotropically distributed.

Optical fiber structure for efficient use of pump power

A high-power optical fiber device comprising a pump source of light-emitting facets, optical means for collimating and converging the array, an optical beam rotator for transforming the array by rotating individual light emissions, and an optical fiber structure having a core surrounded by an inner cladding for transferring pump energy into the core, the inner cladding having a cross-sectional shape in the form of a convex polygon.

High-power optical fiber amplifier or laser device

Growing community of inventors

Cambridge, MA, United States of America

Martin H Muendel