NORLAND PRODUCTS INCORPORATED 2540 Route 130 Building 100

NORLAND PRODUCTS INCORPORATED 2540 Route 130 Building 100 Cranbury, NJ 08512 www. norlandprod. com Tel 609 -395 -1966 Fax 609 -395 -9006 Basic Interferometry For PC Polished Connectors Neal Wagman Norland Products Inc

PC Polish Concept 2540 Route 130 Building 100 Cranbury, NJ 08512 § § Spherical polish Fiber at apex ADVANTAGE: Surface quality only critical at center of connector. Fiber

PC Polish Concept 2540 Route 130 Building 100 Cranbury, NJ 08512 § On connection: § § § Fibers meet in intimate optical contact. No air gap. Fibers compress until ferrules contact. Ferrules take majority of compressive force.

Importance Of Controlling Undercut And Protrusion 2540 Route 130 Building 100 Cranbury, NJ 08512 A. Undercut §Backreflections §Internal connector reflections can cause spurious modulation and noise in laser light (Feedback Lasers) § Reflection noise is an important concern in analog video

Importance Of Controlling Undercut And Protrusion 2540 Route 130 Building 100 Cranbury, NJ 08512 B. Protrusion High forces concentrated on the fiber – Causes Fiber Pushback and affects long term performance

Interferometry 2540 Route 130 Building 100 Cranbury, NJ 08512 Submicron measurements of differential height by reflecting monochromatic light off a surface and combining with light reflecting off a standard to form constructive and destructive interference patters.

Why Use Interferometry? 2540 Route 130 Building 100 Cranbury, NJ 08512 Problem n Standard QC of connectors n Inspect for scratches n Measure light loss n Backreflection if necessary Not enough for critical systems SOLUTION – Interferometry checks 3 D polish geometry n Assures consistency n Assures long term performance Effects to consider: n Temperature cycling n Contact pressure n Vibration Detailed information = more control over process

Typical Interferometric Image 2540 Route 130 Building 100 Cranbury, NJ 08512 CONSTRUCTIVE INTERFERENCE VERTEX OF APEX OFFSET DESTRUCTIVE INTERFERENCE CENTER OF FIBER

3 D Measurement 2540 Route 130 Building 100 Cranbury, NJ 08512

Fringes = Steps Down Surface 2540 Route 130 Building 100 Cranbury, NJ 08512

Measurement Areas 2540 Route 130 Building 100 Cranbury, NJ 08512 Fitting Area: Centered on the ferrule surface and defined by a circular area having a diameter D with a smaller Extracting Area subtracted from its center. D= 250 microns. Extracting Area: Includes the fiber endface region and the adhesive region and is defined by a circular area having a diameter E. E= 140 microns. Averaging Area: This is set on the fiber surface and defined by a circle having a diameter F. F=50 microns

Radius Of Curvature 2540 Route 130 Building 100 Cranbury, NJ 08512 Radius of sphere defined by Fitting Area Center of Fiber Radius

Offset Of Polish 2540 Route 130 Building 100 Cranbury, NJ 08512 Distance from center of fiber to highest point of ferrule

Spherical Fiber Height 2540 Route 130 Building 100 Cranbury, NJ 08512 SPHERICAL FIBER HEIGHT – the ideal connector endface (ferrule & fiber) is considered to be a continuous sphere. It is defined as the difference in height between the center of the fiber and theoretical height in the center based on the ferrule radius.

Norland CC-6000 2540 Route 130 Building 100 Cranbury, NJ 08512 • • Breakthrough Technology Low cost automated interferometer for analyzing PC/APC connectors that operates on any PC through USB port. Base price < $13 K.

CC 6000 - Results 2540 Route 130 Building 100 Cranbury, NJ 08512 Ø Displays: Quantitative measurements Visual pass or fail ØStores to database ØExports to Excel ØPrints individual reports

CC 6000 - Results 2540 Route 130 Building 100 Cranbury, NJ 08512 Display 3 D color contour map of surface detailing fiber and ferrule endface.

CC 6000 Advantages 2540 Route 130 Building 100 Cranbury, NJ 08512 Breakthrough technology which makes interferometric testing affordable to everyone. Easy-to-use software loads quickly and will not crash. Fast, accurate measurements of PC and APC connectors. Allows quick pass/fail measurements for production. Trouble shooting instrument for the field. Robust system requires no maintenance.

Ideal Polish 2540 Route 130 Building 100 Cranbury, NJ 08512 Circular fringes around ferrule and across fiber

Protrusion 2540 Route 130 Building 100 Cranbury, NJ 08512 Circular fringe jogs away from center as it crosses the fiber

Undercut 2540 Route 130 Building 100 Cranbury, NJ 08512 Circular fringe jogs toward center as it crosses fiber

Good Polish With Some Scratches 2540 Route 130 Building 100 Cranbury, NJ 08512

Fiber Shattered on Cleave 2540 Route 130 Building 100 Cranbury, NJ 08512

Underpolished – High Protrusion 2540 Route 130 Building 100 Cranbury, NJ 08512

Overpolished - Fails 2540 Route 130 Building 100 Cranbury, NJ 08512

Ideal Polish 2540 Route 130 Building 100 Cranbury, NJ 08512 Circular fringes around ferrule and across fiber

CC 6000 for Quality Control 2540 Route 130 Building 100 Cranbury, NJ 08512 Fast measurements provide instant feedback on polish quality in a production process and provide indication if corrective action is required.

Pass/Fail Measurements 2540 Route 130 Building 100 Cranbury, NJ 08512

Smooth Polish – High Offset 2540 Route 130 Building 100 Cranbury, NJ 08512

Undercut with Dirt on Fiber 2540 Route 130 Building 100 Cranbury, NJ 08512

Fail 2540 Route 130 Building 100 Cranbury, NJ 08512

Quality Assurance 2540 Route 130 Building 100 Cranbury, NJ 08512 Pass/Fail assures Long Term Performance PC APC Telecordia 8 7 -25 mm 5 to 12 mm Apex Offset <50μm Fiber Protrusion 0. 05μm 0. 1μm ROC Fiber Undercut (ROC 7 -10 mm) 0. 125 μm (ROC 10 -12 mm) 0. 1 μm (ROC 13 -17 mm) 0. 075μm (ROC 18 -25 mm) 0. 05μm 0. 1μm

Summary 2540 Route 130 Building 100 Cranbury, NJ 08512 Importance of Interferometry ØUsed as a training tool ØUsed for QC of hand or machined polishing ØUsed for Quality Assurance w/Pass/Fail Specs. ØUsed for Trouble Shooting Systems ØGives immediate feedback on connector ØGuarantees Long Term Performance of System

For the Best Connectors 2540 Route 130 Building 100 Cranbury, NJ 08512 Connect-Chek 6000 From Norland Products Inc.