A novel optical coupling scheme that uses a lensed fiber integrated with a long-period fiber grating (LPFG) is proposed. Two experiments are performed to demonstrate the validity of such a scheme in single-mode-fiber–single-mode-fiber (SMF-to-SMF) and laser-diode–single-mode-fiber (LD-to-SMF) coupling setups. The measured results show that for an appropriate lens radius the addition of a LPFG will lead to a higher coupling efficiency over a longer range of working distance than without the LPFG. Coupling efficiencies of ~78% and 35% are achieved for corresponding working distances of ~250 and 110 μm, 1-dB longitudinal tolerances of ~40 and 26 μm, and 1-dB transverse tolerances of ~7.6 and 2.6 μm for SMF-to-SMF and LD-to-SMF, respectively.
© 2000 Optical Society of America
Wen Tzung Chen and Lon A. Wang, "Optical Coupling Method Utilizing a Lensed Fiber Integrated With a Long-Period Fiber Grating," Appl. Opt. 39, 4490-4500 (2000)