Abstract: Disclosed herein are methods, structures, apparatus and devices to integrate polarization filters and power tap couplers on planar photonic circuits that advantageously provide a lower insertion loss to an optical signal and improved optical bandwidth as compared with contemporary designs wherein these two functions are implemented separately.

Abstract: Disclosed are designs and methods of fabrication of silicon carrier-depletion based electro-optical modulators having doping configurations that produce modulators exhibiting desirable modulation efficiency, optical absorption loss and bandwidth characteristics. The disclosed method of fabrication of a modulator having such doping configurations utilizes counter doping to create narrow regions of relatively high doping levels near a waveguide center.

Abstract: A waveguide device that includes a first waveguide, a second waveguide and a transition region. The first waveguide has a first height and the second waveguide has a second height different from the first height. The transition region is between the first waveguide and the second waveguide and includes an asymmetrical taper of the first waveguide.

Abstract: Disclosed herein are methods, structures, apparatus and devices for the termination of unused waveguide ports in planar photonic integrated circuits with doped waveguides such that free-carrier absorption therein may advantageously absorb any undesired optical power resulting in a significant reduction of stray light and resulting reflections.

Abstract: Disclosed herein are techniques, methods, structures and apparatus for providing photonic structures and integrated circuits with optical gratings disposed within cladding layer(s) of those structures and circuits.

Abstract: Disclosed herein are methods, structures, and devices for a silicon carrier-depletion based modulator with enhanced doping in at least part of slab regions between waveguide core and contact areas. Compared to prior designs, this modulator exhibits lower optical absorption loss and better modulation bandwidth without sacrificing the modulation efficiency when operating at comparable bandwidth settings.

Abstract: Disclosed are adaptive structures and methods for generating advanced modulation formats using multiple levels such as PAM-4, PAM-8 as well as regular OOK or PM OOK formats. Structures and methods disclosed include an unequal power splitter that may exhibit a fixed or tunable splitting ratio such that adaptive format(s) may be generated.

Abstract: A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity N×M coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the N×M coupler and the optical amplifiers can be used to adjust an amount of power output from M-1 ports of the N×M coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength.

Abstract: An integrated broadband optical isolator that operates over a wide bandwidth, wherein the optical isolator comprises sinusoidally driven phase modulators inside an interferometer. In one exemplary embodiment the optical isolator comprises: a 1×N input optical coupler, where N>2; a N×1 output optical coupler; N optical waveguides optically connecting the 1×N input optical coupler to the N×1 output optical coupler, each one of the N optical waveguides including two phase modulators, wherein each of the phase modulators are driven at a frequency f and wherein the time it takes an optical signal to travel from the center of one phase modulator in a particular waveguide to the center of the other phase modulator in that particular waveguide is substantially equal to 1/4f.

Abstract: A photonic integrated circuit (PIC) may be optically aligned to a plurality of optical components (e.g., an optical fiber array). Optical alignment may be facilitated by the use of an optical impedance element coupled between a first input/output (I/O) optical waveguide and a second I/O optical waveguide of the PIC. The optical impedance element me be configured to be transmissive during optical alignment and to be non-transmissive during the regular operation of the PIC.

Abstract: Disclosed herein are co-packaging structures, devices, and methods for integrating a photonic integrated circuit (PIC), an electronic integrated circuit including drivers and transimpedance amplifiers (TIAs) and an ASIC having analog-to-digital converters and a digital signal processor positioned on a common (the same) carrier thereby resulting in a compact coherent transceiver while lowering its cost.

Abstract: A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity N×M coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the N×M coupler and the optical amplifiers can be used to adjust an amount of power output from M?1 ports of the N×M coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength.

Abstract: Disclosed herein are techniques, methods, structures and apparatus for providing photonic structures and integrated circuits with optical gratings disposed within cladding layer(s) of those structures and circuits.

Abstract: A photonic device comprising a first waveguide core and a second waveguide core. The first waveguide core is asymmetric relative to an imaginary plane that bisects a height of the first waveguide core and is parallel to the bottom surface of the first waveguide core throughout a first region of the photonic device. A side surface of the second waveguide core is parallel to the first waveguide core throughout the first region of the photonic device.

Abstract: A photonic integrated circuit (PIC) may be optically aligned to a plurality of optical components (e.g., an optical fiber array). Optical alignment may be facilitated by the use of an optical impedance element coupled between a first input/output (I/O) optical waveguide and a second I/O optical waveguide of the PIC. The optical impedance element me be configured to be transmissive during optical alignment and to be non-transmissive during the regular operation of the PIC.

Abstract: An optical coherent transceiver comprising a polarization and phase-diversity coherent receiver and a polarization and phase-diversity modulator on the same substrate interfaced by three grating couplers, on grating coupler coupling in a signal, one grating coupler coupling in a laser signal, and a third grating coupler coupling out a modulated signal.

Abstract: Disclosed are structures and methods directed to waveguide structures exhibiting improved device performance including improved attenuation of scattered light and/or transverse magnetic modes. In an illustrative embodiment according to the present disclosure, a rib waveguide structure including a rib overlying a slab waveguide (or superimposed thereon) is constructed wherein the slab waveguide is heavily doped at a distance from the rib which has a very low overlap with rib guided modes. Advantageously, such doping may be of the P-type or of the N-type, and dopants could be any of a number of known ones including—but not limited to—boron, phosphorous, etc.—or others that increase optical propagation loss. As may be appreciated, the doped regions advantageously absorb scattered light which substantially improves the structures' performance.

Abstract: Techniques, methods, structures and apparatus that provide the efficient coupling of light to/from one or more optical fibers to/from planar grating waveguide couplers positioned on photonic integrated circuits.

Abstract: Disclosed are structures and methods for facet optical coupling of optical fibers to photonic integrated circuits.

Abstract: A photonic integrated circuit (PIC) may be optically aligned to a plurality of optical components (e.g., an optical fiber array). Optical alignment may be facilitated by the use of an optical impedance element coupled between a first input/output (I/O) optical waveguide and a second I/O optical waveguide of the PIC. The optical impedance element me be configured to be transmissive during optical alignment and to be non-transmissive during the regular operation of the PIC.