From single mode to multimode and simplex to multifiber, connector termination processes require the excess fiber to be cleaved and "denubbed" and the residual epoxy (bead) to be removed prior to the polishing operation. While accepted as the industry's standard practice, mechanical hand scribing, or "nick and pull" techniques, are often the source of poor endface quality and low yields resulting in high manufacturing costs and questionable long-term reliability. Mechanical hand scribing techniques are particularly susceptible to operator-dependent variability, tool-dependent variability, and stress propagation inherent to the glass.Fiber optic connector manufacturers have long searched for alternative cleaving technologies that would mitigate the undesirable effects of mechanical hand scribing. Laser cleaving technology, though historically perceived as a costly and limited accessible option, is rapidly gaining acceptance as a viable alternative to mechanical hand scribing. This paper investigates the physics and long-term reliability behind both mechanical hand scribing and laser cleaving. We also explore the practical advantages of manufacturing using laser cleaving technologies.By utilizing a CO2 laser to simultaneously cut both the fiber and epoxy bead, it is shown that these three manual operations: Hand ScribeDenubbingEpoxy Bead Removal can be eliminated by a simple one-step operation of the laser cleaving tool.Once laser cleaving has been efficiently proved-in in a production environment, it is advantageous to requalify the product according to Telcordia GR-326 to assure that the laser cleaving does not adversely affect the performance or long term reliability of the optical connector. In particular:1. Thermal aging (168 hours, 85 degC, uncontrolled humidity)2. Thermal cycle (21 cycles, -40 degC / 75 decC, uncontrolled humidity)3. Humidity aging (168 hours, 75 degC, 95% humidity)are conducted on a batch of 25 connector ends.Finally, to determine if the heat of the CO2 laser hitting the glass may impact the mechanical integrity of the epoxy annulus around the fiber within the ferrules hole, of particular concern is the Adhesive Testing. This test is conducted on 10 undrilled "blank" ferrule connectors.Performance of the Telcordia testing confirms the performance and reliability advantages of laser cleaving of optical connectors. In fact, laser cleaving can actually enhance the reliability of optical connectors and improve the manufacturability of these connectors ultimately enabling cost reductions.
© 2006 Optical Society of AmericaPDF Article