title: Nanoscale resonant-cavity-enhanced germanium photodetectors with lithographically defined spectral response for improved performance at telecommunications wavelengths.
abstract: We demonstrate the use of a subwavelength planar metal-dielectric resonant cavity to enhance the absorption of germanium photodetectors at wavelengths beyond the material's direct absorption edge, enabling high responsivity across the entire telecommunications C and L bands. The resonant wavelength of the detectors can be tuned linearly by varying the width of the Ge fin, allowing multiple detectors, each resonant at a different wavelength, to be fabricated in a single-step process. This approach is promising for the development of CMOS-compatible devices suitable for integrated, high-speed, and energy-efficient photodetection at telecommunications wavelengths.
authors.affiliation: Edward L. Ginzton Laboratory, Stanford University, CA 94305, USA. kcbalram@stanford.edu
authors.forename: Krishna C
authors.initials: KC
authors.lastname: Balram
authors.forename: Ross M
authors.initials: RM
authors.lastname: Audet
authors.forename: David A B
authors.initials: DA
authors.lastname: Miller
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005857:Germanium / Q000737:chemistry* / Q000528:radiation effects; D036103:Nanotechnology / Q000295:instrumentation*; D010781:Photography / Q000379:methods; D010783:Photometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*
chemical_list: D005857:Germanium