An integrated photonics computing system implements a residue number system (RNS) to achieve orders of magnitude improvements in computational speed per watt over the current state-of-the-art. RNS and nanophotonics have a natural affinity where most operations can be achieved as spatial routing using electrically controlled directional coupler switches, thereby giving rise to an innovative processing-in-network (PIN) paradigm. The system provides a path for attojoule-per-bit efficient and fast electro-optic switching devices, and uses them to develop optical compute engines based on residue arithmetic leading to multi-purpose nanophotonic computing.

Optical switch trees are commonly used to route light from one input channel to multiple possible output channels one at a time. As the number of output channels increases, the number of wire-bonding pads increases and the drive electronics becomes more complicated. The optical switch tree comprises an array of optical switches arranged in a plurality of rows of optical switches, each connected by a row bus, which are connected to a first multiplexer and a common power source; and a plurality of columns of optical switches, each connected by a column bus, which are connected to a second multiplexer and a common ground. A control processor selects one of the plurality of columns of optical switches to connect to the common ground, and selects one of the plurality of rows of optical switches to connect to the common power source, thereby selecting a single optical switch in the array of optical switches to activate.

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log.sub.2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.

An integrated photonics computing system implements a residue number system (RNS) to achieve orders of magnitude improvements in computational speed per watt over the current state-of-the-art. RNS and nanophotonics have a natural affinity where most operations can be achieved as spatial routing using electrically controlled directional coupler switches, thereby giving rise to an innovative processing-in-network (PIN) paradigm. The system provides a path for attojoule-per-bit efficient and fast electro-optic switching devices, and uses them to develop optical compute engines based on residue arithmetic leading to multi-purpose nanophotonic computing.

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

An integrated optical beam steering system includes a photonic crystal nanostructure having a plurality of nanoelements, an input surface to receive light from an imager, and a concave output surface which maintains a desired field of view with suitable coupling efficiency. Parameters of the nanoelements are configured to give rise to a photonic bandgap for a predetermined range of wavelengths. Waveguides are disposed in the nanostructure which comprise negative space formed by the absence of nanoelements and are employed to generate a propagating band within the photonic bandgap. The respective waveguides have inputs disposed on the input surfaces of the nanostructure where light propagates in a respective waveguide in total internal reflection. The respective waveguides further have outputs that have paths with curved portions located in the nanostructure and the outputs are configured normal to the concave output surface.

An eye tracker having a first waveguide for propagating illumination light along a first waveguide path and propagating image light reflected from at least one surface of an eye along a second waveguide path. At least one grating lamina for deflecting the illumination light out of the first waveguide path towards the eye and deflecting the image light into the second waveguide path towards a detector is disposed adjacent an optical surface of the waveguide.

An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log.sub.2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.

A laser beam steering device and a system including the same are provided. The laser beam steering device includes a waveguide through which a laser beam passes, and a cladding layer disposed on the waveguide. The cladding layer has a refractive index which changes according to an electrical signal applied thereto and thus a phase of a laser beam passing through the waveguide may be changed.