Variable Optical Attenuator based on thermally tuned Mach-Zehnder Interferometer within a twin core fiber
Résumé
A variable optical attenuator (VOA) based on a tunable Mach-Zehnder interferometer has been produced based on a twin core fiber design. Two achromatic 3 dB-couplers have been manufactured utilizing the fused-stretched technique between both cores of the fiber, in order to obtain a Mach-Zehnder interferometer. A metallic thin layer deposit on one arm of the interferometer allows thermal tuning of the Mach-Zehnder interferometer, which obtains the desired attenuation at the component output. We obtained a −0.5 to −24 dB attenuation-range VOA with an achromatic response from 1535 to 1560 nm.