Abstract: A laser structure includes at least one active layer having doped Ge so as to produce light emissions at approximately 1550 nm from the direct band gap of Ge. A first confinement structure is positioned on a top region of the at least one active layer. A second confinement structure is positioned on a bottom region the at least one active layer.

Abstract: A novel detection pixel micro-structure allowing the simultaneous and continuous detection of several discrete optical frequencies. A focal plane array comprises a plurality of multi-spectral detection pixels and a connecting platform to electrically connect the pixels. Each of the multi-spectral detection pixels form a resonant optical structure that comprises at least two periodic latticed dielectric reflectors, and at least one optical cavity between the said latticed dielectric reflectors. The latticed dielectric reflectors create a plurality of photonic bandgaps in the spectral response of the pixel. In addition, each optical cavity of the pixel comprises at least two optical resonant modes, corresponding to localized Bloch modes supported by the pixel dielectric structure, wherein each optical resonant mode is localized maximally at, and minimally away from, the optical cavity.

Abstract: The mode transforming structure includes a first waveguide structure. A slot waveguide region is coupled to the first waveguide structure. The slot waveguide region includes one or more complementary tapered pairs so near lossless transforming between the first waveguide structure and the slot waveguide region occurs so as to allow optical modes to be transferred between the first waveguide and the slot waveguide region.

Abstract: A photodiode balanced in increased sensitivity and speed. The photodiode includes a semiconductor substrate, an active region formed on the semiconductor substrate, and a comb electrode connected to the active region. The comb electrode includes a plurality of electrode fingers, and each of the electrode fingers includes a transparent electrode contacting the active region, and an opaque electrode formed on the transparent electrode. Here, the width of the opaque electrode is set smaller than the width of the transparent electrode.

Abstract: A photodiode in which increased sensitivity and speed are balanced. The photodiode includes: a semiconductor substrate; a plurality of active regions formed on the substrate by selective epitaxial growth; and a comb electrode provided for each of the plurality of active regions and in communication with each other to electrically connect the active regions together.

Abstract: A method for enhancing photoluminescence includes providing a film disposed over a substrate, the film including at least one of a semiconductor and a dielectric material. Light emission may be activated by thermal annealing post growth treatments when thin film layers of SiO2 and SiNx or Si-rich oxide are used. A first annealing step is performed at a first temperature in a processing chamber or annealing furnace; and, thereafter, a second annealing step is performed at a second temperature in the processing chamber or annealing furnace. The second temperature is greater than the first temperature, and the photoluminescence of the film after the second annealing step is greater than the photoluminescence of the film without the first annealing step.

Abstract: A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.

Abstract: An optical waveguide structure includes an air-via region that receives an optical signal from an optical source. A photonic crystal cladding region is formed on the surface of the air-via region. The photonic crystal cladding region confines the optical signal within the air-via region and propagates the optical signal along the axial direction while ensuring near complete transmission of the optical signal.

Abstract: An optical amplifier on a silicon platform includes a first doped device layer and a second doped device layer. A gain medium is positioned between the first and second doped device layers. The gain medium comprises extrinsic gain materials so as to substantially confine in the gain medium a light signal and allow the optical amplifier to be electrically or optically pumped.

Abstract: A ring resonator structure includes a semiconductor substrate, a core, and a cladding. Either the core or the cladding comprises chalcogenide glass to improve electromagnetic confinement in the ring resonator structure.

Abstract: The invention provides a waveguide with a waveguide core having longitudinal sidewall surfaces, a longitudinal top surface, and a longitudinal bottom surface that is disposed on a substrate. An interface layer is disposed on at least one longitudinal sidewall surface of the waveguide core. A waveguide cladding layer is disposed on at least the waveguide core sidewall and top surfaces, over the interface layer. The waveguide of the invention can be produced by forming a waveguide undercladding layer on a substrate, and then forming a waveguide core on the undercladding layer. An interface layer is then formed on at least a longitudinal sidewall surface of the waveguide core, and an upper cladding layer is formed on a longitudinal top surface and on longitudinal sidewall surfaces of the waveguide core, over the interface layer.

Abstract: An optical device includes a first and a second splitting device. Each of the first and second splitting devices have respective first and second input ports, respective first and second output ports, and a respective transfer matrix. A first optical waveguide is optically coupled to the first output port of the first splitting device and the first input port of the second splitting device. A second optical waveguide is optically coupled to the second output port of the first splitting device and the second input port of the second splitting device. The first and second optical waveguides are configured to introduce a phase shift of ? radians to the optical radiation propagating through the first optical waveguide with respect to the optical radiation propagating through the second optical waveguide.

Abstract: An optical modulator structure includes at least two waveguide structures for inputting and outputting an optical signal. At least one ring resonator structure provides coupling between the at least two waveguide structures. The at least one ring resonator structure includes Ge or SiGe.

Abstract: A resonator structure includes a substrate and a cladding layer formed on the substrate. A plurality of lens-shaped optical structures is formed on the cladding layer. The lens-shaped optical structures comprise chacolgenide glass being exposed to a reflow process so as to make smooth the surface of the resonator structure and increase substantially its Q factor.

Abstract: A fabrication method and materials produce high quality aperiodic photonic structures. Light emission can be activated by thermal annealing post growth treatments when thin film layers of SiO2 and SiNx or Si-rich oxide are used. From these aperiodic structures, that can be obtained in different vertical and planar device geometries, the presence of aperiodic order in a photonic device provides strong group velocity reduction (slow photons), enhanced light-matter interaction, light emission enhancement, gain enhancement, and/or nonlinear optical properties enhancement.

Abstract: A lateral photodiode, with improved response speed, includes a semiconductor substrate having active regions, and a p-type region and an n-type region arranged parallel to the surface of the substrate. The active regions are an n-layer and a p-layer respectively, and stacked in the thickness direction of the substrate to form a p-n junction. In addition, a barrier layer, for preventing movement of carriers from the substrate toward the active region, is provided on the side of the active regions toward the substrate.

Abstract: The mode transforming structure includes a first waveguide structure. A slot waveguide region is coupled to the first waveguide structure. The slot waveguide region includes one or more complementary tapered pairs so near lossless transforming between the first waveguide structure and the slot waveguide region occurs so as to allow optical modes to be transferred between the first waveguide and the slot waveguide region.

Abstract: A method for enhancing photoluminescence includes providing a film disposed over a substrate, the film including at least one of a semiconductor and a dielectric material. A first annealing step is performed at a first temperature in a processing chamber or annealing furnace; and, thereafter, a second annealing step is performed at a second temperature in the processing chamber or annealing furnace. The second temperature is greater than the first temperature, and the photoluminescence of the film after the second annealing step is greater than the photoluminescence of the film without the first annealing step.

Abstract: An optical field concentrator includes a plurality of waveguide layers comprising high index materials having a first defined thickness. At least one nano-layer structure is positioned between said waveguide layers. The at least one nano-layer structure comprises low index materials having a second defined thickness that is smaller than the first defined thickness. A plurality of cladding layers are positioned between the waveguide layers and the at least one nano-layer structure. The cladding layers have a third defined thickness that is larger than the first defined thickness.

Abstract: An optical cavity structure for bending optical signals is provided. The optical cavity structure includes an input port for receiving input optical signals from a first waveguide. The optical cavity structure also includes an interconnecting structure that receives said input optical signals and interconnects said first waveguide to a second waveguide, the interconnecting structure further includes at least four straight edges that orthogonal and of a finite width. The optical cavity structure further includes an output port coupled to the interconnecting structure for providing the second waveguide with the input optical signals. Further, the optical cavity structure may be used to create three dimensional splitter devices and resonators.