Nanopillar Optical Antenna Avalanche Detectors
Avalanche photodetectors (APDs) are essential components in active imaging systems requiring both ultrafast response times to measure photon time of flight and high gains to detect low photon fluxes. APDs improve system Signal to Noise Ratio by combining photon detection and amplification eliminating the need for front end amplifiers. An emerging trend in active imaging focal plane array technologies is reducing the pixel pitch (detector volume) for higher resolution images. However, there is an inherent trade-off between reduced detector volume and APD figures of merit.
This dissertation will focus on the design, fabrication and electro-optic characterization of a novel detector architecture "3D Nanopillar Optical Antenna Avalanche Detectors" (3D-NOAADs) for shrinking both the absorption and multiplication volumes using III-V nanopillars, while enhancing the optical absorption via a self aligned 3D plasmonic antenna. Wavelength tuning and hybridization of the optical absorption via Surface Plasmon Polariton Bloch Waves (SPP-BWs) and Localized Surface Plasmon Resonances (LSPRs) will be discussed. Photo-generated carrier transport from the absorption region into the multiplication region and subsequent impact ionization will also be discussed. Single pixel 3D-NOAADs exhibit substantially lower excess noise factors compared to bulk, low breakdown voltages ~ 8 V and gain-bandwidth products > 100 GHz.