Abstract: An embodiment waveguide polarization rotator includes an optical waveguide and an overlay strip. The optical waveguide has an input end and an output end oppositely disposed thereon. The optical waveguide is operable to receive, at the input end, an input optical signal having a mode having an input polarization. The optical waveguide is further operable to generate, at the output end, an output optical signal having an output polarization orthogonal to the input polarization. The overlay strip is disposed over and non-orthogonally crosses the optical waveguide. The overlay strip has a first end laterally offset from the optical waveguide by a first offset distance and a second end laterally offset from the optical waveguide by a second offset distance.

Abstract: Embodiments are provided for an improved 2×1 switch cell design with integrated photodiode for off-state monitoring. In an embodiment, am optical switch comprises a 2×1 multi-mode interferometer (MMI) coupler including two input waveguides jointly coupled to an output waveguide, and a photodetector coupled to an edge of a first waveguide of the input waveguides, and positioned next to a side of the output waveguide. In another embodiment, an optical chip comprises two input waveguides parallel to each other, and an output waveguide coupled to the two input waveguides. The optical chip further includes a photodetector coupled to a first waveguide of the two input waveguides, and positioned next to the output waveguide, and a branch waveguide extending from the first waveguide into the photodetector.

Abstract: Recursive optimization algorithms can be used to determine which idle photonic switching elements to configure in N×N switching fabrics to achieve crosstalk suppression. Different algorithms are used to achieve different levels of optimization. Embodiment full optimization techniques may configure all inactive cells to reduce crosstalk, and consequently may provide the best noise performance and highest power usage. Partial optimizations may configure fewer than all inactive cells to reduce crosstalk, and may provide sub-optimal noise performance at lower power usages. Differential partial optimization algorithms configure inactive cells in different stages of a photonic switching fabric. Fewer than all cells in a given stage may be configured by some algorithms.

Abstract: Crosstalk can be reduced in optical waveguide bundles by varying the widths of individual waveguides. Using different width waveguides reduces the growth of crosstalk between the optical waveguides, thereby allowing the waveguides to be placed in closer proximity to increase waveguide density on the chip and/or reduce the routing space required for the waveguide bundle. Moreover, varying the width of a waveguide spiral may reduce crosstalk, which can increase power efficiency when implemented in coiled or folded waveguide thermal optical (TO) devices.

Abstract: Crosstalk can be suppressed in photonic switching fabrics by activating unused photonic elements in a manner that manipulates the inactive connections and inhibits the propagation of cross-talk over the switching fabric. For example, unused photonic elements can be set to a cross or bar configuration to block first and second order crosstalk from propagating to the output ports, thereby reducing noise in the output signals. All of the unused elements can be activated in order to maximize crosstalk suppression. Alternatively, fewer than all of the unused elements may be activated to achieve a balance between crosstalk suppression and power conservation. Photonic switch architectures can be configured to use pre-determined cross-talk suppression maps (e.g., patterns of activated unused cells) for the various switching configurations, which may be computed using a recursive algorithm.

Abstract: The invention provides a method for fabricating planar waveguiding structures with embedded microchannels. The method includes the step of depositing, over a planar template having at least one indented feature comprising a ridge of a first optical material and a narrow trench adjacent thereto, a second optical material, and the step of subsequent annealing thereof, so that an embedded hollow microchannel forms within the trench. The method provides planar structures wherein the ridge and the embedded microchannel cooperate to form an optical waveguiding structure having a waveguiding direction collinear with the embedded microchannel. Embodiments of the method for forming microfluidic devices integrating ridge waveguides with hollow microchannels having surface access points for fluid delivery, and for forming photonic crystals, are disclosed together with corresponding device embodiments.

Abstract: The invention provides a method for fabricating planar waveguiding structures with embedded microchannels. The method includes the step of depositing, over a planar template having at least one indented feature comprising a ridge of a first optical material and a narrow trench adjacent thereto, a second optical material, and the step of subsequent annealing thereof, so that an embedded hollow microchannel forms within the trench. The method provides planar structures wherein the ridge and the embedded microchannel cooperate to form an optical waveguiding structure having a waveguiding direction collinear with the embedded microchannel. Embodiments of the method for forming microfluidic devices integrating ridge waveguides with hollow microchannels having surface access points for fluid delivery, and for forming photonic crystals, are disclosed together with corresponding device embodiments.

Abstract: A tapered optical fiber component is provided that has an optical fiber with a cladded region. An optical core passes through the cladded region. The cladded region has a tapered extended first region drawn down in diameter to form an effective area region that has a predetermined effective area. The tapered extended first region is formed to adiabatically concentrate an optical signal for propagation through the effective area region of reduced diameter. The power density of the optical signal propagating through the effective area region is increased as an inverse function of the effective area.

Abstract: A tapered optical fiber component is provided that has an optical fiber with a cladded region. An optical core passes through the cladded region. The cladded region has a tapered extended first region drawn down in diameter to form an effective area region that has a predetermined effective area. The tapered extended first region is formed to adiabatically concentrate an optical signal for propagation through the effective area region of reduced diameter. The power density of the optical signal propagating through the effective area region is increased as an inverse function of the effective area.