Where the telecommunication industry standardized their optical connectivity performance with visual, optical and geometrical measurements, the specialty fiber industry traditionally performs only a visual inspection on their fibers assemblies.
The need for optical measurement (insertion loss/return loss) is due to the nature of the various applications in spectroscopy, medical, industrial not often that critical. SMA alike interconnects are often sufficient as they hold the fiber in free air and don’t perform a physical connection between fiber like the telecom connectors like SC, LC, etc.
With the growing applications of high-power laser applications we see that connectivity solutions tend to experience a growing rate of defects on fiber burn defects at the fiber-tip. Many companies relate the fiber burn effect to cleaning issues at the fiber-tip and even with the stringed cleaning procedures, these burn effects still occur.
What most companies have not realize is that the geometry of the fiber-tip could be a significant influencer on this issue. It might relate to the fact that geometrical measurement of connectorized large core fibers, with SMA alike connectors, were simply not available.
The traditional interferometers might offer a SMA connector interface (using ceramic ferrules) however the fiber measurement is performed over an area of 250um according to the IEC/Telcordia standard. With the large core specialty fibers that ranging from 125 to 1200um it simply wasn’t available in the industry.
Supporting our customers with these challenges, we understood that there is a great unawareness about the fiber geometry after polishing at the fiber/connector tip. With free-standing SMA connectors, like the Amphenol Fibergrip, the fibers are often domed and not flat as expected.
“How much of a fiber radius, roughness (like edge chipping), angle or other minor defects is expected to be safe from experiencing fiber reflection issues with high-power laser applications? Can we perform pass/fail measurements on fiber geometry and relate this with an acceptance criteria for our outgoing inspection” where a few questions that were addressed to Fiber Optic Center’s technical team.
Northlab Photonics developed the Proview LD and XD interferometers to measure large core specialty fibers with a range 125-1200 um allowing assembly operations to measure the final end-product of fiber and connector surface at angle, roughness and radius etc.
- NorthLab proview LD Fiber End Face Interferometer & Microscope - 125-720um
(Part#: IF-02-01001) - NorthLab proview XD Fiber End Face Interferometer & Microscope - 250-1200um.
(Part#: IF-12-01001)
The unit offers 3D viewing and pass/fail criteria that can be match with the quality acceptance criteria required for the individual application.
The Proview LD and XD are available with a range of interconnects, like SMA, LD-80 as well as ST and FC connector interfaces for physical contact connectivity solutions. With bare fiber adapters accessories also bare fibers can be measured. The very small desktop unit works with a tablet/laptop using Windows 8/10.
