Monolithic asymmetric optical waveguide grating resonators including an asymmetric resonant grating are disposed in a waveguide. A first grating strength is provided along a first grating length, and a second grating strength, higher than the first grating strength, is provided along a second grating length. In advantageous embodiments, the effective refractive index along first grating length is substantially matched to the effective refractive index along second grating length through proper design of waveguide and grating parameters. A well-matched effective index of refraction may permit the resonant grating to operate in a highly asymmetric single longitudinal mode (SLM). In further embodiments, an asymmetric monolithic DFB laser diode includes front and back grating sections having waveguide and grating parameters for highly asymmetric operation.

Monolithic asymmetric optical waveguide grating resonators including an asymmetric resonant grating are disposed in a waveguide. A first grating strength is provided along a first grating length, and a second grating strength, higher than the first grating strength, is provided along a second grating length. In advantageous embodiments, the effective refractive index along first grating length is substantially matched to the effective refractive index along second grating length through proper design of waveguide and grating parameters. A well-matched effective index of refraction may permit the resonant grating to operate in a highly asymmetric single longitudinal mode (SLM). In further embodiments, an asymmetric monolithic DFB laser diode includes front and back grating sections having waveguide and grating parameters for highly asymmetric operation.

Hybrid optical integration places very strict manufacturing tolerances and performance requirements upon the multiple elements to exploit passive alignment techniques as well as having additional processing requirements. Alternatively, active alignment and soldering/fixing where feasible is also complex and time consuming with 3, 4, or 6-axis control of each element. However, microelectromechanical (MEMS) systems can sense, control, and activate mechanical processes on the micro scale. Beneficially, therefore the inventors combine silicon MEMS based micro-actuators with silicon CMOS control and drive circuits in order to provide alignment of elements within a silicon optical circuit either with respect to each other or with other optical elements hybridly integrated such as compound semiconductor elements. Such inventive MEMS based circuits may be either maintained as active during deployment or powered off once the alignment has been locked through an attachment/retention/latching process.

Hybrid optical integration places very strict manufacturing tolerances and performance requirements upon the multiple elements to exploit passive alignment techniques as well as having additional processing requirements. Alternatively, active alignment and soldering/fixing where feasible is also complex and time consuming with 3, 4, or 6-axis control of each element. However, microelectromechanical (MEMS) systems can sense, control, and activate mechanical processes on the micro scale. Beneficially, therefore the inventors combine silicon MEMS based micro-actuators with silicon CMOS control and drive circuits in order to provide alignment of elements within a silicon optical circuit either with respect to each other or with other optical elements hybridly integrated such as compound semiconductor elements. Such inventive MEMS based circuits may be either maintained as active during deployment or powered off once the alignment has been locked through an attachment/retention/latching process.

Methods and systems for grating couplers incorporating perturbed waveguides are disclosed and may include in a semiconductor photonics die, communicating optical signals into and/or out of the die utilizing a grating coupler on the die, where the grating coupler comprises perturbed waveguides. The perturbed waveguides may include rows of continuous waveguides with scatterers extending throughout a length of said perturbed waveguides a variable width along their length. The grating coupler may comprise a single polarization grating coupler comprising perturbed waveguides and a non-perturbed grating. The grating coupler may comprise a polarization splitting grating coupler (PSGC) that includes two sets of perturbed waveguides at a non-zero angle, or a plurality of non-linear rows of discrete shapes. The PSGC may comprise discrete scatterers at an intersection of the sets of perturbed waveguides. The grating coupler may comprise individual scatterers between the perturbed waveguides.

Methods and systems for grating couplers incorporating perturbed waveguides are disclosed and may include in a semiconductor photonics die, communicating optical signals into and/or out of the die utilizing a grating coupler on the die, where the grating coupler comprises perturbed waveguides. The perturbed waveguides may include rows of continuous waveguides with scatterers extending throughout a length of said perturbed waveguides a variable width along their length. The grating coupler may comprise a single polarization grating coupler comprising perturbed waveguides and a non-perturbed grating. The grating coupler may comprise a polarization splitting grating coupler (PSGC) that includes two sets of perturbed waveguides at a non-zero angle, or a plurality of non-linear rows of discrete shapes. The PSGC may comprise discrete scatterers at an intersection of the sets of perturbed waveguides. The grating coupler may comprise individual scatterers between the perturbed waveguides.

Methods and devices for a plasmonic circuit are described. A planar plasmonic device is configured with a controlling gate structure and when coupled to a complementary plasmonic device, a switching circuit can be realized. Also, by varying the properties of the complementary plasmonic device, the circuit can also operate as an amplifier. By use of combinations of this plasmonic circuit element, more advanced circuits and logic functions can be arrived at.

An optical apparatus comprising an optical device having an optical input-output face, at least two planar waveguide arms being located on a substrate, an optical splitter being located on the substrate, and, an optical grating coupler being located on the substrate. The optical splitter has an optical input and a plurality of optical outputs, each optical output being optically connected to a corresponding one of the planar waveguide arms. The optical grating coupler is connected to receive light from each planar waveguide arm and form diffraction pattern therefrom such that a principal maximum of one of the diffraction patterns overlaps with a principal maximum of another of the diffraction patterns on the optical input-output face of the optical device, the principal maxima of the one and another of the diffraction patterns being directed in different directions.

An optical apparatus comprising an optical device having an optical input-output face, at least two planar waveguide arms being located on a substrate, an optical splitter being located on the substrate, and, an optical grating coupler being located on the substrate. The optical splitter has an optical input and a plurality of optical outputs, each optical output being optically connected to a corresponding one of the planar waveguide arms. The optical grating coupler is connected to receive light from each planar waveguide arm and form diffraction pattern therefrom such that a principal maximum of one of the diffraction patterns overlaps with a principal maximum of another of the diffraction patterns on the optical input-output face of the optical device, the principal maxima of the one and another of the diffraction patterns being directed in different directions.

The optical device coupleable to a waveguide to receive an optical signal from the waveguide generally has at least two diffraction grating devices optically coupled to one another and having corresponding spectral responses, the spectral response of at least one of said diffraction grating devices being tunable to adjust an amount of overlapping between the spectral responses of the at least two diffraction grating devices.