An optical circuit that has a first input waveguide, at least a first output waveguide and an optical path between the first input waveguide and the at least a first output waveguide. A first totally internally reflecting (TIR) waveguide switch lies on the optical path between the first input waveguide and the at least a first output waveguide. A wavelength selective filter is disposed on the optical path between the first input waveguide and the at least one output waveguide, the wavelength selective filter being transmissive for light in a first wavelength range and reflective for light in a second wavelength range.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

A cross-connect switch architecture is described. A cross-connect switch device includes a cross-point switch array, a plurality of photo detectors and a plurality of amplifiers. The cross-point switch array includes a plurality of switches. Each switch is coupled between a respective photo detector and a respective amplifier and is configured to couple the respective photo detector to the respective amplifier when the switch is selected.

A pseudo all-to-all connected system for optical communications are provided. A plurality of nodes are grouped into a node-division multiplexing (NDM) node. An electrical shuffle comprising a plurality of electrical traces connects each port of the plurality of nodes to at least one optical transceiver. The at least one optical transceiver is configured to multiplex a plurality of electrical signals from the plurality of nodes into a plurality of wavelength division multiplexing (WDM) optical signals, the electrical shuffle being configured to route the plurality of electrical signals from each port of the plurality of nodes to form one of a plurality of ordered sequences of signals from the plurality of nodes. A fiber shuffle is configured to route the plurality of WDM optical signals to and from a plurality of NDM connectors.

Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.

A data center network node (28) comprises one or more switch (18,19,22,23) configured to link an optical transceiver (16,17) to an optical connection comprising a multi-core optical fiber (30) having a plurality of cores (31). For each core (31), the one or more switch (18,19,22,23) is configurable between a first configuration in which an optical signal on a said core (31) of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core (31) of the multi-core optical fiber (30).

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.

An optical device includes a plurality of optical input ports, a plurality of optical output ports, a wavelength dispersion arrangement and at least one optical beam steering arrangement. The plurality of optical input ports is configured to receive optical beams each having a plurality of wavelength components. The wavelength dispersion arrangement receives the optical beams and spatially separates each of the optical beams into a plurality of wavelengths components. The optical beam steering arrangement has a first region onto which the spatially separated wavelength components are directed and a second region onto which any subset of the plurality of wavelength components of each of the optical beams is selectively directed after the wavelength components in each of the subsets are spatially recombined with one another. The optical beam steering arrangement selectively directs each of subset of the plurality of wavelength components to a different one of the optical output ports.

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode.