Abstract: The disclosure provides an optical probe comprising an optical waveguide attached to a molecular switch that produces an altered optical signal upon binding a target molecule. The disclosure also provides an optical sensor system comprising an optical probe, a light source configured to emit the excitation light to be coupled into the optical waveguide of the optical probe; and a detector.

Abstract: Improved spin-microwave coupling is provided using a microwave cavity having a galvanic element connecting two points on its walls. This configuration can provide an unusual cavity mode having a highly concentrated magnetic field (to provide good coupling to a spin system) and a spread-out electric field (to reduce loss, since the electric field is almost entirely in vacuum). The galvanic element preferably includes a nano-scale current concentration feature (i.e., sub 100 nm lateral dimensions) to concentrate the magnetic field. The spin system of interest is preferably disposed in proximity to this current concentration feature. Applications include coherent quantum optical-microwave transduction and quantum memories.

Abstract: A dispersion-engineered 2D optical phased array device includes optical slow light waveguides [202, 208, 218] arranged parallel to each other; waveguide bends [206, 216] optically coupling ends of adjacent waveguides of the optical slow light waveguides to form a serpentine optical configuration; wherein the optical slow light waveguides comprise first waveguides of a first waveguide type and second waveguides of a second waveguide type, wherein the first waveguides and the second waveguides are arranged adjacent to each other and alternate with each other; wherein the optical slow light waveguides comprise phased array sections forming a phased array [214], wherein first waveguides and second waveguides have dispersion slopes of opposite sign and the same group index; wherein the optical slow light waveguides comprise slow light delay waveguide sections [210] that provide a delay between adjacent waveguides.

Abstract: Improved quantum transducers based on ensembles of quantum emitters are provided. This work improves the efficiencies of such transducers by compensating for the detrimental effects of inhomogeneous broadening of transition frequencies in such systems. This approach is built upon the insight that the temporal shape of the drive supplying the energy required for transduction can be experimentally tuned. Hence, it is an additional degree of freedom for designing efficient transducers. We pose the design of the drive as a scattering theory optimization problem, where the transduction efficiency is the quantity being maximized, and employ numerical optimization techniques to solve it.

Abstract: A photonic crystal optical phased array device has a dispersion engineered slow light waveguide region; a mode coupler region capable of optically coupling an input waveguide to the dispersion engineered slow light waveguide region; and optical antenna regions integrated within the dispersion engineered slow light waveguide region. The dispersion engineered slow light waveguide region has a substantially linear dispersion relation within a predetermined operational bandwidth of the optical phased array device. The optical antenna regions are formed by an alteration of a periodic structure of the photonic crystal and are capable of radiating light out from the dispersion engineered slow light waveguide region.

Abstract: An integrated Ti:Sapphire laser device includes a substrate [100], a first waveguide resonator [102] composed of a gain medium integrated onto the substrate in a planar technology configuration, a frequency doubler [104] composed of a second order nonlinear material integrated onto the substrate in a planar technology configuration, and a second waveguide resonator [106] composed of a titanium doped sapphire gain medium integrated onto the substrate in a planar technology configuration.

Abstract: Silicon carbide on insulator is provided by bonding bulk silicon carbide to a substrate with an oxide-oxide fusion bond, followed by thinning the bulk silicon carbide as needed. A doping-selective etch for silicon carbide is used to improve thickness uniformity of the silicon carbide layer(s).

Abstract: The disclosure provides an optical probe comprising an optical waveguide attached to a molecular switch that produces an altered optical signal upon binding a target molecule. The disclosure also provides an optical sensor system comprising an optical probe, a light source configured to emit the excitation light to be coupled into the optical waveguide of the optical probe; and a detector.

Abstract: A photonic crystal optical phased array device has a dispersion engineered slow light waveguide region; a mode coupler region capable of optically coupling an input waveguide to the dispersion engineered slow light waveguide region; and optical antenna regions integrated within the dispersion engineered slow light waveguide region. The dispersion engineered slow light waveguide region has a substantially linear dispersion relation within a predetermined operational bandwidth of the optical phased array device. The optical antenna regions are formed by an alteration of a periodic structure of the photonic crystal and are capable of radiating light out from the dispersion engineered slow light waveguide region.

Abstract: Silicon carbide on insulator is provided by bonding bulk silicon carbide to a substrate with an oxide-oxide fusion bond, followed by thinning the bulk silicon carbide as needed.

Abstract: A crossed nanobeam structure for strain engineering in semiconductor devices is provided. For example, such a structure can be used for a low-threshold germanium laser. While the photonic crystal nanobeam enables light confinement in a subwavelength volume with small optical loss, another crossing nanobeam induces high tensile strain in the small region where the optical mode is tightly confined. As maintaining a small optical loss and a high tensile strain reduces the required pumping for achieving net optical gain beyond cavity losses, this technique can be used to develop an extremely low-threshold Ge laser source. Moreover, the structure can be easily integrated into electronic and photonic circuits.

Abstract: A photonic crystal (PC) device including one or more resonant optical structures defined by the photonic crystal structure is affixed to the end face of an optical fiber. The PC device is fabricated on a separate substrate, and then affixed to the fiber end face. This transfer can be facilitated by device templates which are laterally supported by tabs after an undercut etch. The tabs can be designed to break during transfer to the fiber, thereby facilitating transfer. Registration marks and/or the use of device templates having the same diameter as the fiber can be used to provide lateral alignment of the fiber to the resonant optical structures. Such alignment may be needed to provide optical coupling between the fiber and the resonant optical structures.

Abstract: An optical fiber is combined with a photonic crystal structure (PCS) that is optically coupled to the optical fiber. The fiber has an exposed fiber surface, and the PCS is affixed to the optical fiber and disposed on or in proximity to the exposed fiber surface. The PCS includes an elongate probe member configured for biological probing. The elongate probe member includes an optical resonant cavity. In an experiment, this was accomplished using an optical fiber tip with a semiconductor template attached to its side face. The semiconductor structure had a thin, needle-like tip (including a nanobeam cavity) which can be suitably inserted inside (or broken off inside) a biological cell without causing cytotoxicity.

Abstract: A photonic crystal (PC) device including one or more resonant optical structures defined by the photonic crystal structure is affixed to the end face of an optical fiber. The PC device is fabricated on a separate substrate, and then affixed to the fiber end face. This transfer can be facilitated by device templates which are laterally supported by tabs after an undercut etch. The tabs can be designed to break during transfer to the fiber, thereby facilitating transfer. Registration marks and/or the use of device templates having the same diameter as the fiber can be used to provide lateral alignment of the fiber to the resonant optical structures. Such alignment may be needed to provide optical coupling between the fiber and the resonant optical structures.

Abstract: A crossed nanobeam structure for strain engineering in semiconductor devices is provided. For example, such a structure can be used for a low-threshold germanium laser. While the photonic crystal nanobeam enables light confinement in a subwavelength volume with small optical loss, another crossing nanobeam induces high tensile strain in the small region where the optical mode is tightly confined. As maintaining a small optical loss and a high tensile strain reduces the required pumping for achieving net optical gain beyond cavity losses, this technique can be used to develop an extremely low-threshold Ge laser source. Moreover, the structure can be easily integrated into electronic and photonic circuits.

Abstract: Electrical pumping of photonic crystal (PC) nanocavities using a lateral p-i-n junction is described. Ion implantation doping can be used to form the junction, which under forward bias pumps a gallium arsenide photonic crystal nanocavity with indium arsenide quantum dots. Efficient cavity-coupled electroluminescence is demonstrated in a first experimental device. Electrically pumped lasing is demonstrated in a second experimental device. High speed modulation of a single mode LED is demonstrated in a third experimental device. This approach provides several significant advantages. Ease of fabrication is improved because difficult timed etch steps are not required. Any kind of PC design can be employed. Current flow can be lithographically controlled to focus current flow to the active region of the device, thereby improving efficiency, reducing resistance, improving speed, and reducing threshold.

Abstract: An optical fiber is combined with a photonic crystal structure (PCS) that is optically coupled to the optical fiber. The fiber has an exposed fiber surface, and the PCS is affixed to the optical fiber and disposed on or in proximity to the exposed fiber surface. The PCS includes an elongate probe member configured for biological probing. The elongate probe member includes an optical resonant cavity. In an experiment, this was accomplished using an optical fiber tip with a semiconductor template attached to its side face. The semiconductor structure had a thin, needle-like tip (including a nanobeam cavity) which can be suitably inserted inside (or broken off inside) a biological cell without causing cytotoxicity.

Abstract: Electrical pumping of photonic crystal (PC) nanocavities using a lateral p-i-n junction is described. Ion implantation doping can be used to form the junction, which under forward bias pumps a gallium arsenide photonic crystal nanocavity with indium arsenide quantum dots. Efficient cavity-coupled electroluminescence is demonstrated in a first experimental device. Electrically pumped lasing is demonstrated in a second experimental device. This approach provides several significant advantages. Ease of fabrication is improved because difficult timed etch steps are not required. Any kind of PC design can be employed. Current flow can be lithographically controlled to focus current flow to the active region of the device, thereby improving efficiency, reducing resistance, improving speed, and reducing threshold. Insulating substrates can be employed, which facilitates inclusion of these devices in photonic integrated circuits.

Abstract: A photonic crystal (PC) device including one or more resonant optical structures defined by the photonic crystal structure is affixed to the end face of an optical fiber. The PC device is fabricated on a separate substrate, and then affixed to the fiber end face. This transfer can be facilitated by device templates which are laterally supported by tabs after an undercut etch. The tabs can be designed to break during transfer to the fiber, thereby facilitating transfer. Registration marks and/or the use of device templates having the same diameter as the fiber can be used to provide lateral alignment of the fiber to the resonant optical structures. Such alignment may be needed to provide optical coupling between the fiber and the resonant optical structures.

Abstract: Electrical control of the emitter of a coupled quantum emitter-resonant cavity structure is provided. Electrodes are disposed near a semiconductor quantum dot coupled to a semiconductor optical cavity such that varying an applied bias at the electrodes alters an electric field at the quantum dot. Optical input and output ports are coupled to the cavity, and an optical response of the device relates light emitted from the output port to light provided to the input port. Altering the applied bias at the electrodes is capable of altering the optical response. Preferably, the closest electrode to the cavity is disposed between or away from angular lobes of the cavity mode, to reduce loss caused by the proximity of electrode to cavity. The present approach is applicable to both waveguide-coupled devices and non-waveguide devices.