Coupling loss analysis in fiber tip lens and Micro Fabry Perot Multiplexer and demultiplexer connection

Fiber tip lens technology has been employed to reduce coupling loss in fiber to Micro Fabry Perot Multiplexer (FP MUX) and fiber to Micro Fabry Perot Demultiplexer (FP DEMUX) connection. The convex type of fiber tip lens is proposed for FP MUX coupling connection while the concave type of fiber tip lens for FP DEMUX coupling connection. Finite Difference Time Domain (FDTD) numerical method simulation model for 50 μm and 65 μm radius of fiber tip lens have been developed for coupling loss performance analysis. In this analysis, Dense Wavelength Division Multiplexing (DWDM) light ranging from 1270 nm to 1610 nm wavelength has been launched onto the fiber tip lens and lens characteristic is done in terms of focus distance and beam size. Coupling loss analysis shows extremely low loss has been achieved, which are below 6 nW and 0.3 nW for 65 μm radius of convex and concave type of fiber tip lens respectively. This analysis contributes to an optimal configuration of lens in FP MUX and FP DEMUX connection with minimal coupling loss.