Design and analysis of a tunable optical channel drop filter based on high index contrast Si/Air broadband reflectors

A simple tunable optical channel drop filter has been designed for applications in the WDM networks operating at C and L bands. The filter is comprised of two broadband reflectors based on high index contrast Si/Air multilayer separated by a tunable air gap with micro comb drive actuators to realize this tunability. The transfer characteristic of the broadband reflector is modeled using an optical simulation module based on Transfer matrix method (TMM). The filter is then modeled using Airy function incorporating the multiple reflections inside the tunable air gap and it is capable of tuning over a large stop band of width 190nm around the central wavelength 1550nm.