Micro-hyperboloid lensed fibers for efficient coupling from laser chips

A novel technique is presented for producing micro-hyperboloid lensed fibers for efficient coupling to semiconductor laser chips. A three-step process including a precision mechanical grinding, a spin-on-glass (SOG) coating and an electrostatic pulling process is used to form the hyperboloid lens structure on a flat-end single mold fiber (SMF) with the core diameter of 6.6 μm. Micro-hyperboloid lensed fibers with tunable radii of curvature around 4.18 - 4.83 μm can be formed on the SMF end face. A high average coupling efficiency around 80% and low coupling variation of 0.116 ± 0.044% are obtained for the produced fibers. The developed method is efficient to produce micro-hyperboloid lensed fibers for high-performance light coupling between the SMF and the semiconductor diode lasers.