Application of lensed fiber collimator to miniature CWDM filter device

Because of the miniature trend in most fiber optic device, we propose and experimentally verify a coarse wavelength division multiplexing (CWDM) device with lensed fiber collimators. Our key idea is to use a tiny gradient index fiber lensed fiber less than the dimension of o0.14 × L0.5 mm to replace the traditional gradient index lens collimator o3.2 × L11 mm. The insertion loss of a pair of 0.27 pitch lensed fiber collimator is measured in both axial and lateral direction. Then, the thin film filter is sandwiched with the lensed fiber collimators to work as CWDM device. Our experimental result shows the center wavelength and bandwidth are 1549 and 17 nm, respectively. Furthermore, owing to the tiny size and low cost, the lensed fiber collimator will provide a wide utilization in the design of other passive devices and biosensors. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 54:319–322 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26539