Wide-range tunable Fabry-Perot array filter for wavelength-division multiplexing applications

A new design for a Fabry-Perot-based array filter for wavelength-division multiplexing (WDM) applications is proposed. The device is composed of two partially reflective mirrors; the surface of one of the mirrors is stepwise. Not only does the configuration of multiple air-gap cavities into a single unit provide wavelength tunability but the channel numbers can be expanded. A fourchannel multiplexer has been demonstrated. The results revealed that a compact and cost-effective WDM device should be easily attainable.