MCW 4 MEMSactuated Tunable Optical Microtoroidal Resonators Jin

MCW 4 MEMS-actuated Tunable Optical Microtoroidal Resonators Jin Yao, and Prof. Ming C. Wu © 2006 University of California Prepublication Data Spring 2006

Overview and Motivation MEMS-actuated Waveguides • Silicon microresonators Microtoroidal Structure • Compactness • Integration with electronics and MEMS • Microtoroidal structure • Single resonant mode in radial direction • 3 D structure achieved with smooth surface Schematic Overview © 2006 University of California Prepublication Data Spring 2006

Fabricated Device and Characterization Fabricated Device 500 nm Toroidal Edge Microtoroidal Optical Characterization • Extinction ratio 23 d. B • Measured loaded Q by curve fitting Qload~43, 000 Structure 5 μm RMS roughness 0. 26 nm © 2006 University of California Prepublication Data Spring 2006

2 nd Generation process optimization design (I) Ring layer patterning Surrounding align and patterning Thermal oxidation thinning down Six. Ny Si. O 2 Si © 2006 University of California Prepublication Data Spring 2006

2 nd Generation process optimization design (II) Patterning and prepare the formation Toroidal formation and surface smoothness © 2006 University of California Prepublication Data Spring 2006 Wafer bonding

2 nd Generation process optimization design (III) Waveguides patterning Dice and release © 2006 University of California Prepublication Data Spring 2006

Summary • First demonstration of silicon microtoroidal resonators integrated with optical waveguides – Rounded 3 -D silicon structures with atomic surface smoothness – Compact size and high Q device • 2 nd Generation process optimization design to further increase optical performance © 2006 University of California Prepublication Data Spring 2006