Multichannel Tunable WDM-filters
Y. Yi, S. Akiyama, X. Duan and L. C. Kimerling
Sponsor: NSF, MRSEC
A multichannel tunable WDM-filter is an out-of-plane microcavity device with a hollow air-defect layer, designed with lithographically processed cantilever arms that monolithically integrate the two Bragg mirror elements (see Fig. 1a).
Fig. 1(a) Schematic of a multichannnel tunable WDM-filter, whose hollow air-defect layer thickness is electrically actuated by lithographically processed cantilever arms.
Fig. 1(b) Tunable shift in the resonance peak of the reflectivity profile, as a function of applied electrical bias.
An applied voltage bias actuates the cantilever arms, thereby changing the hollow air-defect thickness and altering the resonant wavelength of this microcavity (see Fig. 1b). The large size-design of hollow air-defect layer results in two resonant wavelengths, located at nm and nm, within the microcavity stopband.
Potential applications of such tunable structures are as a dynamic add/drop filter for multiple WDM channels, whose function can be toggled on or off under low applied voltage.