Optical fiber with low curvature radius

TELNET R.I.’s products are continually evolving and include single-mode optical fiber optimized against curvature. This type of fiber, which is compatible with the ITU G.652 standard (Standard single-mode fibers), allows optimum installation of a fiber-optic network without added attenuation caused by curvature.

The difficulties sometimes posed by the interior distribution of fiber-optic cables due to high curvature radii – 30 mm.—, which must be respected to avoid losing optical power in transmission, are well-known.

The same is true of service connections, where the main goal is to design cables that are flexible, compact, and equipped with mechanical protection for easy installation in existing conduits.

The new fibers with low curvature radii are the best suited for these network points.

There are two different types of fiber. The first allows curvature radii of 15 mm and is fully compatible with the G.652 standard. The second type, with a radius of 7.5 mm, goes one step further and is a true revolution in indoor wiring, since it allows true 90º angles that have been impossible up to this point. 

Both types of fiber are compatible with the normal connectors, as well as with fusion splicing machines. This simplifies installation and maintenance of a fiber-optic network that combines standard single-mode fibers on the backbone network with low-curvature fibers in the service connection and interior distribution.

Another clear advantage of these fibers is the significant reduction in the size of the user terminal jacks and junction boxes (up to 16 times smaller).

As shown in the image, this is because less space is needed to house the fibers respecting the minimum curvature radius.

The values of loss from splices and connections, in the case of 15 mm-radius fiber, are similar to those of standard G.652 single-mode fiber. They are only slightly better with 7.5 mm-radius fibers, whose main geometrical characteristic is a reduction in core diameter to 7 microns.

The tests carried out by TELNET on this type of fiber, as well as the evaluations received from customers who have tried them, couldn’t be more positive.

Undoubtedly, from now on, low-curvature fibers will be an essential part of the deployment of fiber-to-the-home networks, FTTH, in the future, as they bring broadband communications closer to users.