(800) 473-4237 / 508-992-6464 sales@focenter.com

Fiber Design and Manufacturing

 

Preform Fabrication Consulting Services  

Fiber Optic Center, Inc. (FOC) offers preform fabrication consulting services to manufacturers of specialty optical preforms and fibers. Included is guidance selecting the right MCVD fabrication system for your needs, post-installation troubleshooting to meet exacting product specs, developing custom solutions, training personnel, and writing standard operating procedures (SOPs)

A unique and particularly valuable service at FOC is Larry Donalds’ troubleshooting expertise to overcome the many preform fabrication and fiber draw issues manufacturers face when producing specialty optical fibers.  Larry’s consulting includes guidance selecting the right MCVD fabrication system for your needs, post-installation troubleshooting to meet exacting product specs, developing custom solutions, training personnel, and writing standard operating procedures (SOPs).

 Tips

 

Reproducibility Tip

As we all know, the internal temperature of the deposition tube is what matters, since the reaction is occurring on the inside. However, the process pyrometer is reading the external temperature. SG Controls offers a diameter control system, which controls and provides an optical measurement of the tube. This system is closed loop, with the pressurization system controlling tube back pressure with feedback from the diameter measurement and set-point. Having an automated system to control tube diameter is very important. While I’ve had some success controlling diameter manually, that approach is not nearly as reproducible as an automated system.

 

Temperature Tip

As you probably know, you can add dopants such as phosphorous and fluorine to reduce the deposition temperature.

 

Hand-held Pyrometer Tip

You do not need to purchase an expensive blackbody unit. Instead, purchase a hand-held standard that is calibrated with a blackbody standard. In addition, you could temporarily mount the hand-held pyrometer on the fire carriage to spot-check the process pyrometer calibration.

 

Preform Tip (keeping the preform straight during collapse)

Companies like SG Controls offer stainless-steel, water-cooled burners with nitrogen curtains to reduce the hot zone width, which prevents preform sagging during collapse. Adjustable flow nitrogen jets on the outside edges of the burner blow against the tube to uniformly reduce the hot zone width. This allows the operator to adjust the hot zone width during collapse. This piece of equipment can enhance uniformity and fiber yields.

About Larry Donalds

 

Larry Donalds is Business Development, Fiber Design and Manufacturing, bringing more than 35 years of experience from 3M Company in St. Paul, MN, after recently retiring.  During his time with 3M Company, he spent 24 years in the development and manufacture of specialty optical fiber utilizing “voice of the customer,” helping 3M design and produce optical fibers to meet specific customer applications and performance criteria.

Projects included the development and production of PM, PZ, EDFA (Erbium Doped Fiber Amplifier) fiber, radiation-hardened fiber for gyroscopes, solution doping of preforms, patent development for Oxyfluoride Erbium fiber, organometallic rare earth deposition and a rare earth single mode fiber bend and position sensor.

In his fiber position at 3M, Larry maintained and operated MCVD equipment from SG Controls Ltd of Cambridge, England, whom FOC has represented in North America for over 25 years.  Larry has achieved several awards during his career including 3M Golden Step Award, Photonics Circle of Excellence Award, R&D 100 Award, 3M Circle of Technical Excellence Awards in 1983, 2001 and 2008 and the 3M Ideation Challenge award in 2017.