Abstract: An optical device comprising a tunable optical frequency comb generator. The comb generator includes an interferometer, and an optical feed-back loop waveguide.

Abstract: A method, comprising modulating digital data onto an optical carrier. Modulating includes intensity splitting the optical carrier in an input optical coupler of an interferometer. The interferometer including two or more controllable optical waveguides located on a substrate, each controllable optical waveguide connecting the input optical coupler to an output optical coupler of the interferometer and having a two-state modulator along a segment thereof. Modulating include optically modulating separate data streams onto each of the optical carriers produced by the splitting. The two or more controllable optical waveguides are connected to transmit an output to the output optical coupler, substantially different light amplitudes and/or phases when the two-state modulators of the two or more controllable optical waveguides are in different states, as driven by the data streams having different information content.

Abstract: An optical device comprising a tunable optical frequency comb generator. The comb generator includes an interferometer, and an optical feed-back loop waveguide.

Abstract: An optical modulator device comprising an interferometer. The interferometer includes an input optical coupler, an output optical coupler, and two or more controllable optical waveguides located on a substrate. Each controllable optical waveguide connects the input optical coupler to the output optical coupler and has two-state modulator along a segment thereof. The two or more controllable optical waveguides are connected to transmit an output to the output optical coupler, substantially different light amplitudes and/or phases when the two-state modulators of the two controllable optical waveguides are in different states, as driven by data streams having different information content. The two or more controllable optical waveguides are configured to modulate the light amplitudes and/or phases in a substantially same manner when the two-state modulators are in identical states.

Abstract: Various exemplary embodiments relate to an optical isolator in an integrated optical circuit including: a first optical modulator configured to provide a first periodic phase modulation on an input optical signal; a second optical modulator configured to provide a second periodic phase modulation on the modulated optical signal; and an optical waveguide having a length L connecting the first optical modulator to the second optical modulator; wherein the phase difference between the first and second periodic phase modulation is ?/2, and wherein the length L of the optical waveguide causes a phase delay of ?/2 on an optical signal traversing the optical waveguide.

Abstract: An optical device comprising a tunable optical frequency comb generator. The comb generator includes an interferometer, and an optical feed-back loop waveguide.

Abstract: A photonic integrated circuit (PIC) having a waveguide-grating coupler with two evanescently coupled waveguides. The first waveguide is fabricated using materials suitable for manufacturing active optical elements in the PIC. The second waveguide is fabricated using materials capable of providing a relatively high index-of-refraction contrast for the constituent waveguide grating. The waveguide-grating coupler is compatible with the III-V semiconductor technology while being relatively easy to fabricate on an industrial scale.

Abstract: An optical device comprising a substrate having a planar surface and having an optical core thereon. The device also comprises a two-dimensional grating located in the optical core, said two-dimensional grating being formed by a regular two-dimensional pattern of light-refractive structures, one of said light-refractive structures being located at each node of a regular 2D lattice located in a laterally bounded region. The device also comprises first and second optical waveguides being on the planar substrate and having ends end-coupled to the two-dimensional grating, the first optical waveguide being such that a direction of propagation near the end thereof is substantially along a primitive lattice vector of said 2D lattice, the second optical waveguide being such that a direction of propagation near the end thereof is not-parallel to a primitive lattice vector of said regular 2D lattice.

Abstract: An optical device comprising a planar waveguide located on a planar substrate, the planar waveguide including a light-transmissive layer and an optical grating coupler being located along the planar substrate and being adjacent to and optically coupled to the planar waveguide. The optical coupler includes an optical grating of the light-transmissive layer. The optical grating includes a periodic arrangement of light-refractive structures and one or more slotted openings separating the optical grating into two or more grating segments that have long axes that are substantially parallel to a propagation direction of a light beam configured to pass between the planar waveguide and the optical coupler. Pitch distances between adjacent ones of the grating segments are less than a wavelength of the light beam divided by an effective refractive index of the light-transmissive layer.

Abstract: A photonic integrated circuit comprises a plurality of optical waveguides. Some waveguides cross some other waveguides at respective crossing locations. Some waveguides have varying widths wherein a width of a waveguide at a respective crossing location is smaller than the wavelength of the optical signal.

Abstract: A coherent optical detector having a waveguide circuit, in which a plurality of waveguides are connected to a waveguide grating. In a representative embodiment, the waveguide grating serves at least three different functions, e.g., those of a fiber-optic coupler, a polarization splitter, and two power splitters, one for each of two orthogonal polarizations. Various embodiments of the coherent optical detector can be used to demodulate various forms of polarization-division-multiplexed (PDM) QAM- and/or PSK-modulated optical communication signals.

Abstract: A photonic integrated circuit (PIC) having a waveguide-grating coupler with two evanescently coupled waveguides. The first waveguide is fabricated using materials suitable for manufacturing active optical elements in the PIC. The second waveguide is fabricated using materials capable of providing a relatively high index-of-refraction contrast for the constituent waveguide grating. The waveguide-grating coupler is compatible with the III-V semiconductor technology while being relatively easy to fabricate on an industrial scale.

Abstract: An optical transmitter includes a set of optical waveguides and first, second, and third optical modulators. Output ends of the optical waveguides of the set form a two-dimensional array capable of end-coupling the optical waveguides of the set to a multimode optical fiber in response to the array being located to optically face one end of the multimode optical waveguide. The first optical modulator is optically connected to a first of the optical waveguides of the set, and each of the second and third optical modulators is optically connected to the second and third of the optical waveguides of the set. The set of optical waveguides is configured to provide a coupling matrix of rank three or more between the optical modulators and optical propagation modes in the multimode optical fiber.

Abstract: An optical photonic device comprising a planar semiconductor substrate having a light-guiding layer thereon, a primary laser light source in said light-guiding layer and a vertical coupler optically coupled to the primary laser light source by waveguide portions of the light-guiding layer. The vertical coupler is configured to receive a light beam from the primary laser light source and redirect the light beam in a direction that is substantially perpendicular to a surface of the planar substrate.

Abstract: A photonic integrated circuit (PIC) having a waveguide-grating coupler with two evanescently coupled waveguides. The first waveguide is fabricated using materials suitable for manufacturing active optical elements in the PIC. The second waveguide is fabricated using materials capable of providing a relatively high index-of-refraction contrast for the constituent waveguide grating. The waveguide-grating coupler is compatible with the III-V semiconductor technology while being relatively easy to fabricate on an industrial scale.

Abstract: A photonic integrated circuit comprises a plurality of optical waveguides. Some waveguides cross some other waveguides at respective crossing locations. Some waveguides have varying widths wherein a width of a waveguide at a respective crossing location is smaller than the wavelength of the optical signal.

Abstract: An apparatus, comprising an optical switch having Nin optical input ports and Nout optical output ports. The optical switch includes an input array of 1×Nout optical switches, an output array of Nin×1 optical switches and a plurality of optical crossconnect zones located in-between the input array and the output array. Nin and Nout are integers greater than 1, and, each of Nin*Nout output waveguide arms of the 1×Nout optical switches are optically coupled to a corresponding one of Nin*Nout input waveguide arms of the Nin×1 optical switches comprising an optical switch.

Abstract: Various exemplary embodiments relate to an optical isolator in an integrated optical circuit including: a first optical modulator configured to provide a first periodic phase modulation on an input optical signal; a second optical modulator configured to provide a second periodic phase modulation on the modulated optical signal; and an optical waveguide having a length L connecting the first optical modulator to the second optical modulator; wherein the phase difference between the first and second periodic phase modulation is ?/2, and wherein the length L of the optical waveguide causes a phase delay of ?/2 on an optical signal traversing the optical waveguide.

Abstract: An apparatus that comprises an optical-mode-converter. The optical-mode-converter includes a optical waveguide including a segment directly located on a substrate and a cantilevered segment located over said substrate and separated from said substrate by a cavity, and, said cantilevered segment includes a core surrounded by a cladding. The optical-mode-converter also includes a dielectric material filling said cavity and contacting said cantilevered segment over said cavity, wherein said dielectric material has a refractive index that is less than a refractive index of said cladding and that is no more than about 20 percent less than said refractive index of said cladding.

Abstract: An optical coherent detector that employs an interleave-chirped arrayed waveguide grating (AWG). The AWG has a periodic chirp pattern that enables the AWG to function as an optical 90-degree hybrid. If the AWG is implemented using a birefringent material, then the AWG can also function as a polarization demultiplexer. In one embodiment, the AWG is designed to simultaneously function as a wavelength demultiplexer, a polarization demultiplexer for each wavelength-division-multiplexed (WDM) signal component, and a 90-degree hybrid for each polarization-division-multiplexed component of each WDM signal component.