Abstract: Sensing circuit, detection control method, fingerprint identification module and display apparatus are provided. The sensing circuit comprises a photoelectric conversion element, an energy storage circuit, a switch control circuit, a discharge control circuit and a voltage conversion circuit. The photoelectric conversion element controls potential of first terminal of energy storage circuit according to received optical signal; the switch control circuit controls first terminal of energy storage circuit to be connected to or disconnected from conversion control node; the discharge control circuit controls conversion control node be connected to or disconnected from first voltage terminal; the voltage conversion circuit controls to output voltage signal outputted by output terminal according to second and/or third voltage signals.

Abstract: Beam monitors, methods of use and fabrication are provided herein. Beam monitors can include a rounded beam cavity with one or more waveguide connected thereto, from which a signal can be used to determine one or more beam characteristics. Such monitors can include a beam intensity monitor that includes a cylindrical beam cavity with a rectangular waveguide extending from a periphery, from which beam intensity can be determined. An advanced beam monitor can include a multi-moded beam cavity having multiple waveguides connected at distinct locations, each corresponding to a differing excitation mode. Such monitor can include an elliptical beam cavity and five waveguides connected thereto, signals from which can be used to determine beam charge, beam position and beam size in both the x-direction and y-directions. Beam monitors can be stand-alone devices or integrated within linear accelerators. Accelerators can include off-axis beam monitor coupling ports and on-axis tuning features.

Abstract: Waveguide devices, associated components and methods. Waveguide devices can include a rectangular waveguide having first and second rectangular ports at one end, and first and second circular waveguides extending from opposing broad sides of the waveguide to provide either full isolation or full transmission between first and second ports. The waveguide can include a fixed short at one circular waveguides and a short with adjustable biasing structure at the other circular waveguide to accommodate broader ranges of high-power capabilities. The waveguide device can be stacked by connecting circular waveguides of adjacent structures to provide an isolator with additional ports or an adjustable directional coupler. The adjustable shorting structure can include plunger or screw-type threads.

Abstract: A reflectarray metasurface for quantum-cascade lasing includes: (1) a substrate; and (2) an array of subcavities disposed on the substrate. Each subcavity in the array of subcavities includes (a) a first metallic layer disposed on the substrate; (b) a layer of a quantum-cascade laser active material disposed on the first metallic layer; and (c) a second metallic layer disposed on the layer of the quantum-cascade laser active material. At least some subcavities in the array of subcavities have inhomogeneous widths, and the array of subcavities is configured to reflect an incident light of at least one resonant frequency with amplification.

Abstract: A metasurface reflector for quantum cascade lasing is disclosed. The metasurface reflector uses an array of subcavities disposed on a substrate and spaced with a sub-wavelength period. Each of the subcavities includes a layer of quantum-cascade-laser-active material sandwiched between two metallic layers. The array of subcavities reflect an incident light of a resonant frequency with amplification. When used with an output coupler, a quantum cascade laser beam can be generated.

Abstract: A metasurface reflector for quantum cascade lasing is disclosed. The metasurface reflector uses an array of subcavities disposed on a substrate and spaced with a sub-wavelength period. Each of the subcavities includes a layer of quantum-cascade-laser-active material sandwiched between two metallic layers. The array of subcavities reflect an incident light of a resonant frequency with amplification. When used with an output coupler, a quantum cascade laser beam can be generated.