Apc Fiber Connector Angle

Upc connectors are polished with no angle but are slightly curved for better core alignment.

Apc fiber connector angle.

Angled polished physical contact apc also called as apc fiber connector is best for high bandwidth applications and long haul links since it offers the lowest return loss rl characteristics of connectors currently available. Instead of a contact end face which is perpendicular to the fiber axis the end face is manufactured so that it is at an angle of 8º to the axis. Angled physical contact connectors apc optifiber the most common types of fiber connectors are pc and upc ultra physical contact. The apc connector is altogether much more crafty.

Sc apc connector is polished with an 8 degree angle while sc upc connector is polished with no angle which causes difference in light reflection. Because of the angle the reflected light does not stay in the fiber core but instead leaks out into the cladding. Upc connectors are blue while apc connectors are green. Apc connectors are polished at an 8 degree angle.

Sc upc connector adopts an extended polish method to realize finer fiber surface finish which brings much lower back reflection orl and thus provides much more reliable signal in data center digital tv and telephone. The apc stands for angled physical contact because these connectors allow the surfaces of two connected fibers to be in direct contact with each other and because the fiber end is polished at an angle to prevent reflected light from traveling back up the fiber. They have a slight curvature for better core alignment. Apc connectors feature a fiber endface that is polished at an eight degree angle.

These fc apc connectors have an 8 pre angled ceramic ferrule which when properly polished results in a typical return loss of 60 db. Upc connectors are not exactly flat however. Connectors with apc finishes are made by polishing the fiber at either an 8 or 9 degree angle with a radius of curvature between 5 and 12 mm see figure 1. However the angled end face of the apc connector causes reflected light to reflect at an angle into the cladding versus straight back toward the source.

With upc connectors any reflected light is reflected straight back towards the light source. Any reflection light bounces back from the interface at 16º to the axis which is greater than can be constrained by the fiber core cladding interface so is thus lost. Upc connectors are polished with no angle. Another more obvious difference is color.

Upc connectors are blue while apc adapters are green. Upc connectors are polished with no angle but apc connectors feature a fiber end face that is polished at an 8 degree angle. With upc the fiber ends are more rounded than the pc finish giving greater contact between the glass surfaces. Like illustrated in the following picture.

This causes some differences in return loss.