Fabrication method for endcapped fiber laser pigtails with sub-micron virtual waist positional accuracy

US11500158B2 · kind B2 · utility

Assignee

• Massachusetts Institute of Technology · US

Inventors

• Jason E. Langseth · Malden, US
• Christopher Hwang · Watertown, US
• William J. Nowak · Webster, US
• Daniel B. Miller · New York, US
• David Fouche · Carlisle, US
• Joshua Olitzky · Windham, US

Key dates

• Filing date: Jan 13, 2020
• Grant date: Nov 15, 2022
• Expiry date: Dec 24, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/3692
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Arrays of fiber pigtails can be used to project and receive light. Unfortunately, most fiber pigtail arrays are not aligned well enough for coherently combining different optical beams. This imprecision stems in part from misalignment between the optical fiber and the endcap spliced to the end of the optical fiber. The endcap is often polished, curved, or patterned, causing the light emitted by the endcapped fiber to refract or diffract as it exits the endcap. This refraction or diffraction shifts the apparent position of the beam waist from its actual position. Measuring this virtual beam waist position before and after splicing the endcap to the fiber increases the absolute precision with which the fiber is aligned to the endcap. This increase in absolute precision reduces the deviation in virtual beam waist position among endcapped fibers, making it easier to produce arrays of endcapped fibers aligned precisely enough for coherent beam combining.