Abstract: The present invention provides a polarization converter, and a method for fabricating the same. The polarization converter includes a geometric shape which induces rotation of a polarization of an optical signal from a first polarization state to a second polarization state as the optical signal propagates along the polarization converter. The performance of the polarization converter is maintained in light of inconsistencies in fabrication processes resulting in improved manufacturability.

Abstract: The present invention provides for a semiconductor laser having a narrow linewidth and low power consumption for optical communication applications. According to various embodiments of the invention, a semiconductor laser is provided which includes a grating layer comprising a plurality of segmented gratings, each including a non-grating portion and a grating portion. The segmented gratings are configured to enhance a fundamental mode of the semiconductor laser while sufficiently suppressing modes other than the fundamental mode, providing a narrow linewidth for example. The segmented gratings are also configured to provide an effective length longer than an actual length of the semiconductor laser, leading to smaller device areas and corresponding lower power consumption. A photonic integrated circuit is also provided which includes a plurality of semiconductor lasers, consistent with the present invention, as well as additional optical elements, all provided on a single substrate.

Abstract: Consistent with the present disclosure, a current blocking layer is provided between output waveguides carrying light to be sensed by the photodiodes in a balanced photodetector, and the photodiodes themselves. Preferably, the photodiodes are provided above the waveguides and sense light through evanescently coupling with the waveguides. In addition, the current blocking layer may include alternating p and n-type conductivity layers, such that, between adjacent ones of such layers, a reverse biased pn-junction is formed. The pn-junctions, therefore, limit the amount of current flowing from one photodiode of the balanced detector to the other, thereby improving performance.

Abstract: Consistent with the present disclosure, the number of passive waveguides in a PIC are reduced by directly connecting active components to one another. Accordingly, optical signals propagating in the PIC may experience less loss, and, thus, improved performance may be achieved. In addition, active components may be bent or curved in order to obtain a more compact layout with greater device density. Reduced manufacturing costs can therefore be realized.

Abstract: A photonic integrated circuit (PIC) having multiple Mach-Zehnder (MZ) modulators with different lengths is provided. The modulator lengths are selected to provide optimal performance for each optical path provided on the PIC.

Abstract: Various embodiments of the present invention are directed to integrated circuits having photonic interconnect layers and methods for fabricating the integrated circuits. In one embodiment of the present invention, an integrated circuit comprises an electronic device layer and one or more photonic interconnect layers. The electronic device layer includes one or more electronic devices, and the electronic device layer is attached to a surface of an intermediate layer. One of the photonic interconnect layers is attached to an opposing surface of the intermediate layer, and each of the photonic interconnect layers has at least one photonic device in communication with at least one of the electronic devices of the electronic device layer.

Abstract: Various embodiments of the present invention are directed to nanowire-based photodetectors that can be used to convert information encoded in a channel of electromagnetic radiation into a photocurrent encoding the same information. In one embodiment of the present invention, a photodetector comprises a waveguide configured to transmit one or more channels of electromagnetic radiation. The photodetector includes a first terminal and a second terminal. The first terminal and the second terminal are positioned on opposite sides of the waveguide. The photodetector also includes a number of nanowires. Each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is embedded in the waveguide.

Abstract: Various embodiments of the present invention are directed to nanowire-based modulators that can be used to encode information in a carrier channel of electromagnetic radiation. In one embodiment of the present invention, the modulator includes a waveguide configured to transmit one or more channels of electromagnetic radiation. The modulator includes a first terminal and a second terminal. The first terminal and the second terminal are positioned on opposite sides of the waveguide. The modulator also includes a number of nanowires, wherein each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is operatively coupled to the waveguide. The nanowires modulate the one or more channels when an electrical signal of appreciable magnitude is applied to the first terminal and the second terminal.

Abstract: Consistent with the present disclosure, various optical components are preferably arranged on the surface of a semiconductor substrate such that light propagates in certain components at a direction that is perpendicular to a direction of propagation in other components in order to improve performance and component density.

Abstract: A modulator is disclosed that includes three arms between a splitter portion and a coupler portion. The modulator typically requires at most a ?/2 phase shift between constellation points. Accordingly, the modulator is more efficient and consumes less power.

Abstract: Various embodiments of the present invention are directed to nanowire-based photodetectors that can be used to convert information encoded in a channel of electromagnetic radiation into a photocurrent encoding the same information. In one embodiment of the present invention, a photodetector comprises a waveguide configured to transmit one or more channels of electromagnetic radiation. The photodetector includes a first terminal and a second terminal. The first terminal and the second terminal are positioned on opposite sides of the waveguide. The photodetector also includes a number of nanowires. Each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is embedded in the waveguide.

Abstract: Various embodiments of the present invention are directed to integrated circuits having photonic interconnect layers and methods for fabricating the integrated circuits. In one embodiment of the present invention, an integrated circuit comprises an electronic device layer and one or more photonic interconnect layers. The electronic device layer includes one or more electronic devices, and the electronic device layer is attached to a surface of an intermediate layer. One of the photonic interconnect layers is attached to an opposing surface of the intermediate layer, and each of the photonic interconnect layers has at least one photonic device in communication with at least one of the electronic devices of the electronic device layer.

Abstract: Various embodiments of the present invention are directed to nanowire-based modulators that can be used to encode information in a carrier channel of electromagnetic radiation. In one embodiment of the present invention, the modulator includes a waveguide configured to transmit one or more channels of electromagnetic radiation. The modulator includes a first terminal and a second terminal. The first terminal and the second terminal are positioned on opposite sides of the waveguide. The modulator also includes a number of nanowires, wherein each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is operatively coupled to the waveguide. The nanowires modulate the one or more channels when an electrical signal of appreciable magnitude is applied to the first terminal and the second terminal.

Abstract: A gallium nitride device substrate comprises a layer of gallium nitride containing an additional lattice parameter altering element located over a substitute substrate.

Abstract: Edge-emitting light source and method for fabricating an edge-emitting light source. The edge-emitting light source includes a photonic crystal having at least one waveguide region. An edge-emitting semiconductor structure having a light emitting active layer is incorporated within the at least one waveguide region. Light emitted by the edge-emitting semiconductor structure and within the bandgap of the photonic crystal is confined within the waveguide region and guided out of the photonic crystal through the waveguide region.

Abstract: The etched sidewalls of laterally oxidized VCSEL structures are coated with a dielectric film to inhibit oxidation of the DBR layers during the oxidation process. While oxidation of the DBR mirror layers is not completely eliminated, the number of DBR mirror layers that are oxidized is significantly reduced, thereby reducing the DBR oxide stress.

Abstract: Purely gain-coupled diffraction gratings may be realized for use in QCLs and other edge emitting lasers that lack a typical p-n junction. The periodic, typically heavily n-doped regions of doped diffraction gratings are replaced with p-type regions having significantly lower doping.

Abstract: Refractory metal ELOG mask are used for GaN based VCSELs and edge emitter structures to serve as intracavity contacts. In these structures the refractory metal ELOG masks serve both as ohmic contact metals as well as masks for ELOG.

Abstract: A system and method of using a refractive index sensor to determine a characteristic of a sample. The operation of the system and method allow for determining a change in a bulk index of the sample, and an amount of sample adsorption, using a reflected beam from an interface of the sensor. An embodiment of a system and method further provide for identifying changes in incident angles determine from reflective measurement data of the sensor, in combination with different proportionality constants of the refractive index sensor to determine a characteristic of the sample.

Abstract: The present invention provides a ring laser system comprising forming an optical core by an epitaxial layer overgrowth over an intermediate layer, forming multi-quantum wells adjacent to the optical core and forming an outer structure further comprising a total internal reflector, wherein forming photons within the multi-quantum wells further comprises circulating the photons within the ring laser structure comprising the outer structure, the multi-quantum wells, and the optical core.