Tool for angled cleaving of optical fibers or the like

#The relative widespread and ever increasing use of optical fiber materials as means for carrying optical signals for telecommunications has created a need for devices or tools to cleave the glass of the optical fiber. The cleaved end of the optical fiber should be largely smooth and free from surface imperfections.

#When the glass fiber is terminated, light beams travelling into or out of the optical fiber will have a portion of their light reflected from the end face of the fiber. If this reflected light is directed back towards the source of the light beam it will have deleterious effects, including an increase in the optical noise level and possibly disturb the operation of the light source such as a semiconductor laser.

#However, if the cleaved end of the fiber is not perpendicular, the reflected light will be directed in a direction away from the incident light beam path and will not affect the light source. Similarly, if light travelling in an optical fiber exits an angled cleaved end of the fiber, for instance in a mechanical splice, then any light reflected from the cleaved end will be directed away from the optical axis of the glass fiber, hence the reflected light will not be guided by, and will not propagate back down, the optical fiber. Consequently, no back-reflection will be observed due to the cleaved end. A cleaved end angled at approximately 6°-8° away from the perpendicular will reduce the back reflection of light in an optical fiber to less than −60 dB.

#Various embodiments and examples of the invention will now be described with reference to the accompanying enlarged scale diagrammatic drawings in which:

#FIG. 1 shows an optical fiber clamped between two upper clamping surfaces and two lower surfaces, with the presence of an anvil deflecting the fiber and an edge scoring the tensioned fiber;

#FIG. 2a shows an enlarged view of the tensioned optical fiber, sheared between the corners of the anvil and a lower clamping surface and being scored by the edge of a sharp blade;

#Like parts are referred to by the same, or similar reference numerals throughout the drawings whilst any dimensions or other values quoted herein are given by way of example only and may be varied accordingly to practical requirements.

#This invention reveals the details of the design of a tool for controllably cleaving single or multiple optical fibers with cleaved end angles β in the range 1°-20° and preferably in the range 5°-10° away from the perpendicular to the axis of the fiber.

#In particular the aforesaid prior International Patent Application describes details of a tool for perpendicular cleaving of optical fiber, comprising a pair of spaced apart clamps operable for holding the fiber in a tensioned condition for scoring by a blade whereby subsequent cleaving of the fiber is effected by the tension thereon, whereby spaced apart clamps for holding the fiber are operable on clamping pressure both to clamp and tension the fiber, incorporating also a two-armed anvil which displaces the fiber in addition to the applied tension. At a point in between the arms of the anvil, the tensioned and bent fiber is scored by a blade edge which is moved at an acute angle to the fiber, so causing the fiber to cleave. The tension present in the fiber is aligned along its axis, and because the cleave propagates perpendicular to the internal stress, the resultant cleaved end face is perpendicular to the axis of the optical fiber.