A large-scale single-photonics-based optical switching system that occupies an area larger than the maximum area of a standard step-and-repeat lithography reticle is disclosed. The system includes a plurality of identical switch blocks, each of is formed in a different reticle field that no larger than the maximum reticle size. Bus waveguides of laterally adjacent switch blocks are stitched together at lateral interfaces that include a second arrangement of waveguide ports that is common to all lateral interfaces. Bus waveguides of vertically adjacent switch blocks are stitched together at vertical interfaces that include a first arrangement of waveguide ports that is common to all vertical interfaces. In some embodiments, the lateral and vertical interfaces include waveguide ports having waveguide coupling regions that are configured to mitigate optical loss due to stitching error.

An optical circuit for routing a signal includes a coupler and first and second waveguides. The coupler has an input for the signal and has first and second outputs. The first waveguide has a first optical connection to the first output, and the second waveguide has a second optical connection to the second output. Both waveguides have the same propagation length. The first and second waveguides include different widths at the respective optical connections to the respective outputs. This coupler can be used with another input couplers, two additional waveguides, and two 2×2 output couplers to provide a 90-degree hybrid for mixing signal light and local oscillator light in a coherent receiver or the like.

An optical circuit for routing a signal includes a coupler and first and second waveguides. The coupler has an input for the signal and has first and second outputs. The first waveguide has a first optical connection to the first output, and the second waveguide has a second optical connection to the second output. Both waveguides have the same propagation length. The first and second waveguides include different widths at the respective optical connections to the respective outputs. This coupler can be used with another input couplers, two additional waveguides, and two 2×2 output couplers to provide a 90-degree hybrid for mixing signal light and local oscillator light in a coherent receiver or the like.

System and methods for optical power distribution to a large numbers of sample wells within an integrated device that can analyze single molecules and perform nucleic acid sequencing are described. The integrated device may include a grating coupler configured to receive an optical beam from an optical source and optical splitters configured to divide optical power of the grating coupler to waveguides of the integrated device positioned to couple with the sample wells. Outputs of the grating coupler may vary in one or more dimensions to account for an optical intensity profile of the optical source.

An optical functional device includes: first and second optical couplers each including a multi-mode interferometer waveguide portion having a first end portion and a second end portion, two units of first input/output ports and two units of second input/output ports; and first and second arc-shaped waveguides each optically connecting one of the first and second input/output ports of the first and second optical coupler and one of the first and second input/output ports of the second optical coupler, respectively. Further, the first optical coupler, the second optical coupler, the first arc-shaped waveguide, and the second arc-shaped waveguide constitute a ring resonator, and each of the multi-mode waveguide portions of the first optical coupler and the second optical coupler have a narrow portion, an average width of the narrow portion in a longitudinal direction being narrower than widths at the first end portion and the second end portion.

An optical waveguide crosspoint comprising first and second single multimode interference sections, each single multimode interference section comprising an input face, an output face and sidewalls extending therebetween, the distance between the input face and output face for each single multimode interference section being the; length of the multimode interference section, the lengths of the first and second multimode interference sections being L1 and L2 respectively; at least one primary input optical waveguide connected to the input face of the first single multimode interference section; at least one primary output optical waveguide connected to the output face of the first single multimode interference section; the first single multimode interference section comprising a symmetry axis extending from the center of the input face to the center of the output face; at least one secondary input optical waveguide connected to the input face of the second single multimode interference section; at least one secondary output optical waveguide connected to the output face of the second single multimode interference section; the second single multimode interference section comprising a symmetry axis extending from the center of the input face to the center of the output face; the first and second single multimode interference sections intersecting to form an L shaped compound multimode interference structure; the width of each single multimode interference section in a direction normal to Its symmetry axis being less than 15% of the length of the other single multimode interference section.

In accordance with an example embodiment of the present invention, there is provided an apparatus (160) comprising two inputs configured to receive two optical signals from two fibres (155, 157) from two respective optical transmitters, a beam splitter configured to convert the optical signals into dual rail form, the apparatus being configured to cause the optical signals to interfere with each other, a plurality of single photon detectors configured to measure the dual rail form optical signals, and at least one processing core configured to obtain compensation adjustment information concerning the two fibres and to inform the optical transmitters of the compensation adjustment information.

A compressive/transform imager comprising a lens array positioned above input ports for collecting light into the input ports, waveguides routing the light from the input port to waveguide mixing regions (e.g. multi-mode interference couplers), and detectors for receiving outputs of the waveguide mixing regions.

A large-scale single-photonics-based optical switching system that occupies an area larger than the maximum area of a standard step-and-repeat lithography reticle is disclosed. The system includes a plurality of identical switch blocks, each of is formed in a different reticle field that no larger than the maximum reticle size. Bus waveguides of laterally adjacent switch blocks are stitched together at lateral interfaces that include a second arrangement of waveguide ports that is common to all lateral interfaces. Bus waveguides of vertically adjacent switch blocks are stitched together at vertical interfaces that include a first arrangement of waveguide ports that is common to all vertical interfaces. In some embodiments, the lateral and vertical interfaces include waveguide ports having waveguide coupling regions that are configured to mitigate optical loss due to stitching error.

In accordance with an example embodiment of the present invention, there is provided an apparatus (160) comprising two inputs configured to receive two optical signals from two fibres (155, 157) from two respective optical transmitters, a beam splitter configured to convert the optical signals into dual rail form, the apparatus being configured to cause the optical signals to interfere with each other, a plurality of single photon detectors configured to measure the dual rail form optical signals, and at least one processing core configured to obtain compensation adjustment information concerning the two fibres and to inform the optical transmitters of the compensation adjustment information.