▎ 摘　　要

NOVELTY - Graphene photodetector for detecting photons comprises a waveguide; at least one graphene layer disposed proximate to the waveguide and adapted to be connected to a first electrode at a first end of at least one graphene layer and a second electrode at a second end of at least one graphene layer opposite the first end; and an insulating layer disposed between the waveguide and at least one graphene layer. USE - The devices are useful for detecting photons; for spectroscopy; and for detecting selected wavelength of electromagnetic radiation (all claimed). ADVANTAGE - Improved techniques for graphene photodetectors are provided. The electronic structure of graphene can be unique, resulting in physical and optical properties that can enhance performance of certain opto-electronic devices. Physical and optical properties of graphene-based photodetectors can include an ultra-fast response, for example, up to 1 THz, across a broad spectrum, for example, from 400 nm to 15 mu m or from visible to mid infrared, a linear dispersion electric structure without a bandgap, a strong electron-electron interaction, and photocarrier multiplication. For example, photodetectors based on graphene can display ultrafast response with zero-bias operation over a broad spectral range. DETAILED DESCRIPTION - Graphene photodetector for detecting photons comprises a waveguide; at least one graphene layer disposed proximate to the waveguide and adapted to be connected to a first electrode at a first end of at least one graphene layer and a second electrode at a second end of at least one graphene layer opposite the first end; and an insulating layer disposed between the waveguide and at least one graphene layer; or graphene photodetector for detecting photons comprises at least one graphene layer adapted to be connected to a source electrode at a first end of at least one graphene layer and a drain electrode at a second end of at least one graphene layer opposite the first end; a gate electrode proximate to at least one graphene layer; and a voltage source connected to the gate electrode and configured to modulate a Fermi energy (E(G)) of at least one graphene layer to block absorption of a selected frequency omega of electromagnetic radiation. INDEPENDENT CLAIMS are included for: (1) a method of making a device for detecting photons, which involves providing a silicon-on-insulator wafer; forming a waveguide on the silicon-on-insulator wafer; depositing an insulating layer onto the waveguide; depositing at least one graphene layer onto the insulating layer; and depositing a first electrode and a second electrode, the first electrode deposited at a first end of at least one graphene layer and the second electrode deposited at a second end of at least one graphene layer; (2) a device for spectroscopy, comprising at least one input waveguide; at least one coupler coupled to at least one input waveguide; a spectral separation mechanism coupled to at least one input waveguide to separate the spectral components of electromagnetic radiation; and photodetectors disposed proximate to the spectral separation mechanism, each configured to detect a respective selected frequency component of electromagnetic radiation, and each of the photodetectors having graphene as the photodetecting layer; (3) a device for detecting a selected wavelength of electromagnetic radiation, comprising a scannable interface filter having at least one cavity, the cavity configured to have a resonant wavelength to match the selected wavelength; and at least one photodetector disposed within at least one cavity, at least one photodetector having graphene as the photodetecting layer and being configured to detect the selected wavelength of electromagnetic radiation; and (4) a method for detecting electromagnetic radiation using a device for detecting photons having at least one graphene layer, a source electrode connected to a first end of at least one graphene layer, a drain electrode connected to a second end of at least one graphene layer opposite the first end, a gate electrode proximate to at least one graphene layer, which involves directing electromagnetic radiation to at least one graphene layer; modulating a gate voltage at the gate electrode to modulate a Fermi energy E(G) of at least one graphene layer to block absorption of at least one frequency omega of a spectrum of frequencies omega (E(G)) of the electromagnetic radiation; and detecting a photocurrent I between the source electrode and drain electrode.