angled polish

Helical-bevel coupling is a method of transmitting light energy between two optical fibers with the lowest possible losses and an extremely high return loss, which is over 60 dB.

For this purpose, the monomode fibers are beveled at the ends; this bevel changes the light reflection at the FO end faces and improves the optical return loss. This improved return loss is referred to as high return loss( HRL). The inclination of the bevel is typically about 8 degrees and reflects light reflections from both conductors outward.

Oblique-ground coupling of optical waveguides

With helical-bevel coupling, unlike lens coupling, there is no direct contact between the two optical fibers. Angle Polished Convex( APC) offers a further improvement in reflection properties. This angled ground technology also has a slightly round polish, and the polished end faces have physical contact( PC). These connectors are very low attenuation and reflection-free, but difficult to polish.