Corning Lasertron, Incorporated

Corning Incorporated

Lasertron

Corning Laserton, Inc.

Thomas Chaodung Yang

Steven David Conover

Wayne F Sharfin

Jeffrey Korn

Lee-Ching Hwu

An endface configuration of an optical fiber has a frustum region which is produced by polishing the endface. In order to produce the optimal rounded tip, however, the polished fiber is then fused. To increase coupling efficiency, the vertex angle of the polished frustum region is acute, preferably between 16 and 20&deg;. Further, to create a hyperbolic endface surface, an intermediate frustum region is preferably polished prior to fusing tip. This fused tip is preferably has a circular cross-section.

Polished fused optical fiber endface

A fiber grating stabilized pump laser achieves power stability with a relatively low grating reflectivity of 1.0 to 2.3%. Substantial laser diode output facet reflectivity is provided, between 3.0 and 5.5%. When the optical fiber system provides for no polarization control between the grating and the diode laser, the power reflectivity of the grating, is preferably between 1.7 and 2.3%. The power reflectivity of the laser diode output facet is preferably between 3.4 and 4.9%. In contrast, when provisions are made for polarization control between the grating and laser diode, even lower grating reflectivities are possible, between 1.0 and 2.3%.

Pump laser with low grating reflectivity

A solution for implementing gratings with optical sources where polarization-maintaining fiber is required or desirable utilizes polarization-maintaining fiber between the grating and the optical source. The grating, however, is actually written in regular, or non-polarization-maintaining fiber. The polarization-maintaining fiber is spliced to the non-PM fiber. Since this splice exists in the commercial components, it can be performed in laboratory conditions.

Optical component with polarization-maintaining fiber pigtail splice to regular fiber with grating

An improved fiber endface shape for increasing coupling of optical power from a source into fiber and its manufacture are disclosed. The inventive tip comprises a cleaved end surface that is preferably substantially orthogonal to the fiber's axis and a first and second polished, angled surfaces intersecting the end surface. Break-lines between the angled surfaces and the end surface fall near an edge of a cladding-core interface and preferably outside that interface when the fiber and transmitted light are such that a substantial portion of the light is transmitted in the cladding. A spatial intensity profile of light exiting from the tip is detected during manufacture and is used to monitor the polishing of the angled surfaces. Tests have shown that the inventive tip achieves the coupling efficiency associated with the double-angled wedge-shaped fiber tips while maintaining much of the ease of manufacture associated with the single-angle wedge tips.

Growing community of inventors

North Chelmsford, MA, United States of America

Thomas Chaodung Yang