Abstract: Embodiments of the present disclosure may comprise a system for filling undercuts with an index-matching liquid on a wafer, the system comprising a plurality of edge couplers, each comprising an undercut and a waveguide. Embodiments may also comprise ribs that suspend the waveguide over the undercut. Embodiments may also comprise one or more main buckets and one or more monitor buckets. Embodiments may also comprise a duct that couples together the plurality of edge couplers, the one or more main buckets, and the one or more monitor buckets.

Abstract: A photonics integrated circuit (PIC) chip includes: an input unit, including at least one optical input (IN) and a number of optical outputs (ISO); a modulation unit (MU) including a number of light modulators (M) having optical inputs(S) coupled to optical outputs ISO of the input unit, and optical outputs (T); a first stage optical switch unit (1SOSU) including a number of optical inputs (I) optically coupled to optical outputs T of the MU, and optical outputs (P), a first subset of which define a first subset of optical outputs (O) of the PIC chip; and a second stage optical switch unit (2SOSU) including a number of optical inputs I and optical outputs (O) that define second subset of the optical outputs O of the PIC chip. Each optical switch of 1SOSU and 2SOSU may be configured in a coupler mode; a bar mode; and/or a cross mode.

Abstract: An on-chip Fourier transform spectrometer based on a double-layer spiral waveguide comprises, in order, a waveguide input coupler, a 1×N optical splitter, N double-layer waveguide Y-branch structures, N double-layer spiral waveguides with incremental lengths, N double-layer waveguide Y-branch structures arranged in opposite directions, and N germanium-silicon detectors. The group index difference between the odd mode and the even mode in the double-layer waveguide makes the double-layer spiral waveguide function like an asymmetric Mach-Zehnder interferometer. N double-layer spiral waveguides with incremental lengths are used to achieve a spatial heterodyne based Fourier transform spectrometer. Spectral reconstruction from the measured interference fringes can be achieved by a regression algorithm.

Abstract: A chip-scale silicon-based hybrid-integrated LiDAR system, wherein a transmitting end thereof sequentially comprises a narrow-linewidth tunable laser source, a silicon-nitride-based beam splitter, a silicon-based phase shifter array and a silicon-nitride-based unidirectional transmitting antenna array w.r.t the optical path. Based on the principle of reciprocity of light propagation, the receiving end thereof sequentially comprises a silicon nitride unidirectional receiving antenna array, a silicon nitride beam splitter and a silicon-based coherent receiving module. It also comprises a backup system and an electric controller as the driver of the phase shifters and the processing module. Modules on the silicon platform and the silicon nitride platform are monolithic integrated in a multilayer sandwiched fashion by means of a tapered silicon/silicon nitride evanescent inter-layer coupler; and a gain chip in the tunable laser module and a silicon nitride waveguide are hybrid-integrated by horizontal coupling.

Abstract: A silicon-based reconfigurable microwave photonic multi-beam forming network chip comprises an optical fiber coupler, an optical switch array, an optical divider, an ultra-wideband continuously adjustable optical true delay line array and a detector array; the optical fiber coupler is configured for inputting a single-sideband modulated optical signal of a microwave photonic phased array radar; the optical switch array and optical divider are configured for forming the reconstruction of the number of array elements used for a microwave photonic multi-beam and a microwave photonic single-beam; the ultra-wideband continuously adjustable optical true delay line array is configured for independently adjusting the delay on each microwave array element; and the detector array is configured for outputting a microwave signal. The chip provides large instantaneous bandwidth, high resolution, and reconfigurable microwave photonic multi-beam forming for the microwave photonic phased array radar.

Abstract: A three-dimensional scanning LiDAR based on one-dimensional optical phased arrays comprises a transmitting end, a coherent receiving end and an incoherent receiving end, wherein the transmitting end, the coherent receiving end and the incoherent receiving end are all one-dimensional arrays. A phase control complexity of the three-dimensional scanning phased array is reduced, and a tunable laser with high cost and a grating array antenna with large crosstalk are avoided. The LiDAR provides pure solid-state three-dimensional scanning in speed and integration level and is highly practical.

Abstract: Integrated two-dimensional multi-beam LiDAR transmitter based on the Butler matrix, comprising an tunable laser array, a frequency modulated continuous wave modulator array, an N×N Butler optical matrix network, an N×M optical beam expanding network, an M-path phase shifter array, and an M-path two-dimensional LiDAR emitters.

Abstract: A silicon Fourier transform spectrometer and an optical spectrum reconstruction method are disclosed. The spectrometer includes a waveguide input coupler, cascaded optical switches, unbalanced subwavelength grating (SWG) waveguide pairs, and a germanium silicon detector, where the cascaded optical switches are connected through unbalanced SWG waveguide pairs. The state of the optical switches are adjusted to digitally configure the optical path, so as to constitute a series of unbalanced Mach-Zehnder interferometer (MZI) arrays with different optical path differences, to realize a Fourier transform spectrometer based on spatial heterodyne. The optical spectrum is reconstructed by using a compressed sensing algorithm.

Abstract: A calibration system and related methods for optical phased array chips. The calibration system includes an adjustable mount module, an infrared microscopic observation module, an arrayed driver module, a two-dimensional laser beam scanning module, a photoelectric conversion module and an upper computer, and utilizes computer-vision-enabled positioning and phase error compensation algorithms as software components. Collimated laser is emitted from the target beamforming angle and aimed at the emission aperture of the chip, and is subsequently sampled by the array elements in a reversed injection manner. Based on the reciprocity of light propagation, by maximizing the power reversely output from the bus waveguide of the optical phased array chip, beamforming at the target angle is achieved supported by software implementations of optimization algorithms.

Abstract: A silicon Fourier transform spectrometer and an optical spectrum reconstruction method are disclosed. The spectrometer includes a waveguide input coupler, cascaded optical switches, unbalanced subwavelength grating (SWG) waveguide pairs, and a germanium silicon detector, where the cascaded optical switches are connected through unbalanced SWG waveguide pairs. The state of the optical switches are adjusted to digitally configure the optical path, so as to constitute a series of unbalanced Mach-Zehnder interferometer (MZI) arrays with different optical path differences, to realize a Fourier transform spectrometer based on spatial heterodyne. The optical spectrum is reconstructed by using a compressed sensing algorithm.

Abstract: A silicon- and optical phased array-based integrated optically adjustable delay line, comprising, an optical phased array transmitting unit, a slab waveguide transmitting unit, and an optical phased array receiving unit that are sequentially arranged. By the optical phase control transmitting unit, the phase difference between channels is regulated and controlled via a phase shifter to change a far-field interference light spot and form a wave beam with directivity to regulate and control an incident angle of an optical signal entering the slab waveguide, thus changing the propagation path length of the optical signal. Finally, the optical signal is received by a corresponding optical phased array receiving unit to obtain different delay amounts. Large adjustable delay amount is realized and the delay line has the advantages of simple structure and control and high integration level with high application value in optical communication and microwave photonic and optical signal processing.

Abstract: A chip-scale silicon-based hybrid-integrated LiDAR system, wherein a transmitting end thereof sequentially comprises a narrow-linewidth tunable laser source, a silicon-nitride-based beam splitter, a silicon-based phase shifter array and a silicon-nitride-based unidirectional transmitting antenna array w.r.t the optical path. Based on the principle of reciprocity of light propagation, the receiving end thereof sequentially comprises a silicon nitride unidirectional receiving antenna array, a silicon nitride beam splitter and a silicon-based coherent receiving module. It also comprises a backup system and an electric controller as the driver of the phase shifters and the processing module. Modules on the silicon platform and the silicon nitride platform are monolithic integrated in a multilayer sandwiched fashion by means of a tapered silicon/silicon nitride evanescent inter-layer coupler; and a gain chip in the tunable laser module and a silicon nitride waveguide are hybrid-integrated by horizontal coupling.

Abstract: A silicon- and optical phased array-based integrated optically adjustable delay line, comprising, an optical phased array transmitting unit, a slab waveguide transmitting unit, and an optical phased array receiving unit that are sequentially arranged. By the optical phase control transmitting unit, the phase difference between channels is regulated and controlled via a phase shifter to change a far-field interference light spot and form a wave beam with directivity to regulate and control an incident angle of an optical signal entering the slab waveguide, thus changing the propagation path length of the optical signal. Finally, the optical signal is received by a corresponding optical phased array receiving unit to obtain different delay amounts. Large adjustable delay amount is realized and the delay line has the advantages of simple structure and control and high integration level with high application value in optical communication and microwave photonic and optical signal processing.

Abstract: A three-dimensional scanning LiDAR based on one-dimensional optical phased arrays comprises a transmitting end, a coherent receiving end and an incoherent receiving end, wherein the transmitting end, the coherent receiving end and the incoherent receiving end are all one-dimensional arrays. A phase control complexity of the three-dimensional scanning phased array is reduced, and a tunable laser with high cost and a grating array antenna with large crosstalk are avoided. The LiDAR provides pure solid-state three-dimensional scanning in speed and integration level and is highly practical.

Abstract: Integrated two-dimensional multi-beam LiDAR transmitter based on the Butler matrix, comprising an tunable laser array, a frequency modulated continuous wave modulator array, an N×N Butler optical matrix network, an N×M optical beam expanding network, an M-path phase shifter array, and an M-path two-dimensional LiDAR emitters.

Abstract: An electrooptically tunable waveguide-coupled microresonator. In one example embodiment, the switch includes a photoalignment layer that enhances control of liquid crystal alignment in the cladding near the coupling region of the microresonator and waveguide.

Abstract: An electrooptically tunable waveguide-coupled microresonator. In one example embodiment, the switch includes a photoalignment layer that enhances control of liquid crystal alignment in the cladding near the coupling region of the microresonator and waveguide.