Deterministic cleave of optical fiber

Axial tension is applied to an optical fiber (10) that had been scored at the intended cleave location (12), wherein the axial tension is applied in a time-varying manner to maintain the stress intensity factor for crack on the fiber within an acceptable level to produce a stable crack growth at a reasonable rate to cleave the fiber without requiring polishing of the end surface. Careful control of the applied tension force with time acts to control the velocity of the propagating crack by maintaining substantially constant stress intensity factor. The applied axial tension force is reduced with time and/or crack growth (as crack propagates). As a result, the strain energy in the fiber material is released by formation of a single plane with an optical quality surface without requiring polishing. A substantially flat optical surface of enhanced optical quality is formed at the cleaved end of the optical fiber.