At Photonics West 2013 (San Francisco), fiber-optic network products specialist OFS announced a successful fusion splicing of silica fiber and sapphire fiber using the company's standard S178 portable fusion splicer. A new splicing method overcomes traditional barriers to splicing these fibers caused by the difference in their physical properties, including differences in thermal expansion coefficients and the 200ºC difference in their melting points.
Dr. Tom Liang, an OFS engineering manager based in Norcross, Georgia, worked closely with The Ohio State University to develop the special splicing method after months of investigation and teamwork. The technology development is a major step toward extending the commercial application of sapphire fibers to extremely high temperature instrumentation, says OFS.
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Sapphire fibers can be used for optical sensing in harsh environments and for laser delivery in medical applications. Some examples of sapphire fiber-based sensors include fiber Bragg gratings that can be inscribed into the sapphire fiber, and sapphire fiber-based extrinsic Fabry-Perot interferometric sensors. Sapphire fibers offer excellent mechanical strength, hardness, corrosion resistance, and a high melting point (2050° C). They are used in areas where other instrumentation is not considered acceptable due to geometric constraints, electromagnetic interference, chemical or radiological exposure, or risk of explosion or corrosion.
The major drawbacks to the use of sapphire fibers has been their high optical attenuation and their high cost, both of which have limited the fiber length between the optical sensor and detector. The new splicing technique allows low-attenuation silica fibers to act as a lead-in fiber to significantly reduce the total optical attenuation, says the company.
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