System and method for contactlessly and automatically determining the return loss of an optical fiber connector

A method for contactlessly and automatically determining return loss of an optical fiber connector having a domed combination of an optical fiber and a surrounding support ferrule, the method comprising the steps of:

• (a) determining an undercut/protrusion parameter by:
• (1) imaging an endface of said connector with an interferometric fringe disposed over said fiber and over said ferrule;
• and
• (2) determining said undercut/protrusion parameter based upon an offset of said fringe between said fiber image region and ferrule image region;
• (b) determining a dome polish eccentricity parameter by:
• (1) imaging said endface with an interferometric fringe disposed over said ferrule and about said fiber;
• (2) identifying a fiber center of said fiber;
• (3) fitting an equation to said fringe;
• (4) identifying a fringe center based upon said equation;
• and
• (5) determining said dome polish eccentricity based upon an offset between said fiber center and said fringe center;
• (c) determining a curvature radius parameter by:
• (1) imaging said endface with an interferometric fringe disposed over said ferrule and about said fiber;
• (2) determining a spacing between fringes;
• and
• (3) determining said curvature radius based upon said spacing and a wavelength of light that is utilized to create said interferometric fringe;
• (d) determining a discontinuity parameter by:
• (1) imaging said fiber;
• (2) locating discontinuities in said fiber by evaluating pixel intensifies;
• (3) determining weights for said discontinuities based upon locations of said discontinuities relative to a center of said fiber;
• and
• (4) determining said discontinuity parameter based upon said weights;
• and
• (e) determining a return loss based upon said parameters.

A return loss determination system for contactlessly and automatically determining a return loss of an optical fiber connector having a domed combination of an optical fiber and a surrounding support ferrule, the system comprising:

• an undercut/protrusion (U/P) inspection mechanism for determining an U/P parameter corresponding with an offset of said fiber relative to a curvature of said ferrule along an axis of said fiber;
• a dome polish eccentricity (DPE) inspection mechanism for determining a DPE parameter corresponding with a displacement in a plane perpendicular to said axis between a curvature center of said curvature and a fiber center of said fiber;
• a curvature radius (CR) inspection mechanism for determining a CR parameter corresponding with a radius of said curvature relative to said curvature center;
• a discontinuity (D) inspection mechanism for determining a D parameter to quantify surface discontinuities in said fiber;
• and
• a return loss evaluation mechanism for determining a return loss of said connector based upon said parameters.

A return loss determination system for contactlessly and automatically determining return loss of an optical fiber connector having a domed combination of an optical fiber and a surrounding support ferrule, the system comprising:

• (a) an undercut/protrusion (U/P) inspection system for determining an U/P parameter corresponding with a disparity of said fiber relative to a curvature of said ferrule along an axis of said fiber, said U/P inspection system comprising:
• (1) a first scope with a first interferometer;
• (2) a camera coupled to said interferometer;
• and
• (3) a first machine vision system connected to said camera for receiving a first image of said domed combination, said machine vision system configured to determine said disparity based upon an offset between said fringe in a fiber image region representing said fiber and said fringe in a ferrule image region representing said ferrule;
• (b) a dome polish eccentricity (DPE) inspection system for determining a DPE parameter corresponding with a displacement in a plane perpendicular to said axis between a curvature center of said curvature and a fiber center of said fiber, said DPE inspection system comprising:
• (1) a second scope with a second interferometer;
• (2) a camera connected to said second scope;
• (3) a second machine vision system for receiving a second image of said domed combination, said machine vision system configured to identify a fiber center of said fiber, to fit an equation to said fringe, to identify a fringe center based upon said equation, and to determine said DPE parameter based upon a displacement between said fiber center and said fringe center;
• (c) a curvature radius (CR) inspection system for determining a CR parameter corresponding with a radius of said curvature relative to said curvature center, said CR inspection system comprising:
• (1) a third scope with a third interferometer;
• (2) a camera connected to said third scope;
• (3) a third machine vision system for receiving a third image of said domed combination, said machine vision system configured to determine a spacing between fringes and to determine said CR parameter based upon said spacing;
• (d) a discontinuity inspection system for determining a discontinuity parameter to quantify surface discontinuities in said fiber, said discontinuity inspection system comprising:
• (1) a fourth scope;
• (2) a camera connected to said fourth scope;
• (3) a fourth machine vision system for receiving a fourth image of said domed combination, said machine vision system configured to locate a discontinuity in said endface from said image by scanning through pixel intensifies in said image, configured to weight said discontinuity based upon a location of said discontinuity relative to a center of said endface, and configured to determine said DPE parameter based upon said weight;
• and
• (e) return loss evaluation system connected to said first through fourth machine vision systems, said return loss evaluation system configured to determine a return loss of said connector based upon said parameters.