Abstract: A multi-beam optical phased array on a single planar waveguide layer or a small number of planar waveguide layers enables building an optical sensor that performs much like a significantly larger telescope. Imaging systems use planar waveguides created using micro-lithographic techniques. These imagers are variants of “phased arrays,” common and familiar from microwave radar applications. However, there are significant differences when these same concepts are applied to visible and infrared light.

Abstract: MEMS-actuated optical switches can be implemented on photonic chips. These switches are compact, essentially planar, simple to implement and include only one moving MEMS component per switch. The switches exhibit low optical loss, require low power to operate, and are simple to control and easy to integrate with other optical devices. Each switch has two optical waveguides that are optically coupled in an ON switch state and not coupled in an OFF switch state. An end or a medial section of one of the two waveguides may translate between the ON and OFF states to affect the coupling. Alternatively, a coupling frustrator may translate between the ON and OFF states to affect the coupling.

Abstract: An all-solid state optical transmit/receive terminal includes binary optical switches to steer an optical beam, without mechanical components, phased array of emitters/collectors or large number of phase shifters. A lens optically couples a surface array of emitters/collectors to free space, giving each emitter/collector a respective direction in free space. The emitters/collectors are also coupled, via an “H-tree” or other branched optical waveguide network, to a common input/output port, and from there to a receiver and/or transmitter. The binary optical switches are disposed at optical junctions of the optical waveguide network. ON switches pass an optical signal through the optical waveguide network, between the common input/output port and one or more selected emitter/collectors, thereby selecting a free space direction(s). Only a relatively small subset of the binary optical switches needs to be ON, therefore powered, simultaneously at any given time.

Abstract: A multi-beam optical phased array on a single planar waveguide layer or a small number of planar waveguide layers enables building an optical sensor that performs much like a significantly larger telescope. Imaging systems use planar waveguides created using micro-lithographic techniques. These imagers are variants of “phased arrays,” common and familiar from microwave radar applications. However, there are significant differences when these same concepts are applied to visible and infrared light.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switch network. Each optical switch in the optical switch network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switch network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switch network is ON.

Abstract: A LiDAR system has a field of view and includes a polarization-based waveguide splitter. The splitter includes a first splitter port, a second splitter port and a common splitter port. A laser is optically coupled to the first splitter port via a single-polarization waveguide. An objective lens optically couples each optical emitter of an array of optical emitters to a respective unique portion of the field of view. An optical switching network is coupled via respective dual-polarization waveguides between the common splitter port and the array of optical emitters. An optical receiver is optically coupled to the second splitter port via a dual-polarization waveguide and is configured to receive light reflected from the field of view. A controller, coupled to the optical switching network, is configured to cause the optical switching network to route light from the laser to a sequence of the optical emitters according to a temporal pattern.

Abstract: A LiDAR system includes an array of optical emitters, an objective lens optically coupling each optical emitter to a respective unique portion of a field of view, an optical switching network coupled between a laser and the array of optical emitters and a controller coupled to the optical switching network and configured to cause the optical switching network to route light from the laser to a sequence of the optical emitters according to a dynamically varying temporal pattern and to vary the temporal pattern based at least in part on distance to an object within the field of view. The LiDAR system scans different portions of the field of view differently, such as with different laser power levels, different revisit rates and/or different scan patterns, for example based on likelihood of detecting objects of interest in the various portions or based on likely relative importance of objects likely to be found in the various portions.

Abstract: A LiDAR system includes an array of optical emitters, an objective lens optically coupling each optical emitter to a respective unique portion of a field of view, an optical switching network coupled between a laser and the array of optical emitters and a controller coupled to the optical switching network and configured to cause the optical switching network to route light from the laser to a sequence of the optical emitters according to a dynamically varying temporal pattern and to vary the temporal pattern in a way that reduces risk of eye injury from the laser light.

Abstract: A single photon detection circuit is described that includes a germanium photodiode that is configured with zero voltage bias to avoid dark current output when no photon input is present and also is configured to respond to a single photon input by generating a photovoltaic output voltage. A single electron bipolar avalanche transistor (SEBAT) has a base emitter junction connected in parallel with the germanium photodiode and is configured so that the photovoltaic output voltage triggers an avalanche collector current output.

Abstract: A nanophotonic phased array is configured to generate dynamic three-dimensional imagery when employed as an oscillatory beam-steering device. A scanning nanophotonic phased array generates programmable light fields. That is, a phased array generates reconfigurable light fields when controlled to perform an angular scan of incident illumination synchronized with respect to modulation of the incident illumination.

Abstract: A multi-beam optical phased array on a single planar waveguide layer or a small number of planar waveguide layers enables building an optical sensor that performs much like a significantly larger telescope. Imaging systems use planar waveguides created using micro-lithographic techniques. These imagers are variants of “phased arrays,” common and familiar from microwave radar applications. However, there are significant differences when these same concepts are applied to visible and infrared light.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switch network. Each optical switch in the optical switch network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switch network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switch network is ON.

Abstract: A zero-optical-path-length-difference optical phased array built with essentially planar photonic devices determines a direction to an incoherent optical source, such as a star. The phased array can replace a 3-dimensional star tracker with a nearly 2-dimensional system that is smaller and lighter. The zero-optical-path-length-difference phased array can be optically connected to an interferometer. Driven by a light source, the zero-optical-path-length-difference phased array can be used as an optical projector.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switch network. Each optical switch in the optical switch network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switch network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switch network is ON.

Abstract: A LiDAR system and scanning method creates a two-dimensional array of light spots. A scan controller causes the array of light spots to move back and forth so as to complete a scan of the scene. The spots traverse the scene in the first dimensional direction and in the second dimensional direction without substantially overlapping points in the scene already scanned by other spots in the array. An arrayed micro-optic projects the light spots. Receiver optics includes an array of optical detection sites. The arrayed micro-optic and the receiver optics are synchronously scanned while maintaining a one-to-one correspondence between light spots in the two dimensional array and optical detection sites in the receiver optics.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switching network. Each optical switch in the switching network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switching network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switching network is ON.

Abstract: Embodiments described herein improve the performance of active sensing systems, such as LiDAR systems, and enable detection of objects closer to the system's sensor. Illustrative embodiments enable spatial separation of the excitation and return signal on a photonic integrated chip (“PIC”) such that separate waveguides can be used for the excitation and return signals, enabling isolation of the system's detectors from the excitation source without the use of a splitter or circulator. For example, preferred embodiments avoid loss due to the use of splitters and the need for gating the detector, and are desirably compatible with chip-scale systems. Moreover, illustrative embodiments enable keeping the excitation and detection paths on the same PIC (e.g. in an interleaved configuration), which helps keep the system more compact and avoid issues introduced by parallax.

Abstract: A monostatic optical system adaptable for use as a circulator in a LiDAR system wherein the monostatic optical system includes a photonic integrated circuit and a first light detector. The photonic integrated circuit includes a nonlinear optical device. For example, the device may be a ring resonator or a Mach-Zehnder interferometer. Transmitted light pulses are of sufficient power to alter the optical characteristics of the nonlinear optical device, whereas received reflected light is of low power thereby traveling on a different path to the first light detector. A feedback monitor and tuner may be included to tune the optical characteristics of the nonlinear optical device.

Abstract: A zero-optical-path-length-difference optical phased array built with essentially planar photonic devices determines a direction to an incoherent optical source, such as a star. The phased array can replace a 3-dimensional star tracker with a nearly 2-dimensional system that is smaller and lighter. The zero-optical-path-length-difference phased array can be optically connected to an interferometer. Driven by a light source, the zero-optical-path-length-difference phased array can be used as an optical projector.

Abstract: A coupling interface arrangement is described for a photonic integrated circuit (PIC) device. The PIC includes an interface coupling surface having optical grating elements arranged to form optical output locations that produce corresponding light output beams. A coupling lens couples the light output beams into a conjugate plane at a far-field scene characterized by one or more optical aberrations that degrade optical resolution of the light outputs. The optical grating elements are configured to correct for the one or more optical aberrations.