Dual-wavelength first-order optical differentiators based on bidirectional fiber couplers

Abstract

We simulated a novel dual-wavelength first-order optical differentiator based on a bidirectional fused-fiber coupler. Conventional optical directional couplers act as ultrafast optical differentiators that provide operability at multi-wavelength regions owing to the sinusoidal variations of their transfer functions in the frequency domain. In this study, a dual-wavelength optical differentiator that operates at both 1310 nm and 1550 nm was designed with a fused-fiber coupler under specific conditions. The proposed device has the potential to be used as an ultrafast optical differentiator that provides unparalleled performance with advantages such as wide bandwidth, ease of fabrication, and multi-wavelength operation.