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Spotlight: Si-CMOS compatible materials and devices for mid-IR microphotonics

Analysis of Threshold Current Behavior for Bulk and Quantum-Well Germanium Laser Structures

Single-Crystal Germanium Growth on Amorphous Silicon

Photonic crystal structures for light trapping in thin-film Si solar cells: Modeling, process and optimizations

Engineering broadband and anisotropic photoluminescence emission from rare earth doped tellurite thin film photonic crystals

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).

Cross Sectional Tunable Filter Picture

Fig. 1(a) Schematic of a multichannnel tunable WDM-filter, whose hollow air-defect layer thickness is electrically actuated by lithographically processed cantilever arms.

Tunable Filter Wavelength vs Reflectance Graph

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).[3]  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.

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