Photonic integrated circuit components based on amorphous silicon on insulator technology
We present integrated optic building blocks and functional photonic devices based on amorphous silicon on insulator technology. Efficient deep etched fiber to chip grating couplers, low loss single mode photonic wire waveguides, and compact power splitters are presented. Based on the sub mm photonic wires, 2x2 Mach Zehnder interferometers and add/drop microring resonators (MRRs) with low device footprints and high finesse up to 200 were realized and studied. Compact polarization rotators and splitters with =10 dB polarization extinction ratio were fabricated for the polarization management on chip. The tuning and trimming capabilities of the material platform are demonstrated with efficient microheaters and a permanent device trimming method, which enabled the realization of energy efficient photonic circuits. Wavelength multiplexers in the form of cascaded filter banks and 4x4 routers based on MRR switches are presented. Fabrication imperfections were analyzed and permanently corrected by an accurate laser trimming method, thus enabling eight channel multiplexers with record low metrics of sub mW static power consumption and =1degC temperature overhead. The high quality of the functional devices, the high tuning efficiency, and the excellent trimming capabilities demonstrate the potential to realize low cost, densely integrated, and ultralow power 3D stacked photonic circuits on top of CMOS microelectronics.