Patent classifications
G01S7/4916
Laser sensor module for particle detection with offset beam
A laser sensor module for detecting a particle density of particles, which includes: a laser; a detector; and a mirror. The laser is arranged to emit a laser beam to the mirror. A movement of the mirror is arranged to redirect the laser beam. The laser beam is displaced with respect to a rotation axis of the mirror such that a focus region of the laser beam is moving with a velocity having components normal and parallel to the optical axis of the redirected laser beam such that an angle between the parallel and the normal velocity component is at least a threshold angle of 2°. The detector is arranged to determine a self mixing interference signal of an optical wave within a laser cavity of the laser, the self mixing interference signal being generated by laser light of the laser beam reflected by at least one of the particles.
Photonic edge coupler
A photonic edge coupler includes a slab waveguide and a ridge waveguide. The ridge waveguide includes a silicon wire waveguide, which includes a tapered portion. A first end of the slab waveguide is joined to the ridge waveguide at a junction, and a second end of the slab waveguide forms a first facet. The ridge waveguide defines a longitudinal axis that is associated with a direction of a light signal therein. The first facet is angled at less than 90 degrees relative to the longitudinal axis associated with the direction of the light signal therein. The first facet is disposed opposite to a laser facet associated with a laser waveguide. The longitudinal axis of the ridge waveguide defines a first center point, and the laser facet and the associated laser waveguide define a second center point. The second center point is laterally offset from the first center point.
Handling obstructions and transmission element contamination for self-mixing particulate matter sensors
A portable electronic device is operable in a particulate matter concentration mode where the portable electronic device uses a self-mixing interferometry sensor to emit a beam of coherent light from an optical resonant cavity, receive a reflection or backscatter of the beam into the optical resonant cavity, produce a self-mixing signal resulting from a reflection or backscatter of the beam of coherent light, and determine a particle velocity and/or particulate matter concentration using the self-mixing signal. The portable electronic device is also operable in an absolute distance mode where the portable electronic device determines whether or not an absolute distance determined using the self-mixing signal is outside or within a particulate sensing volume associated with the beam of coherent light. If not, the portable electronic device may determine a contamination and/or obstruction is present that may result in inaccurate particle velocity and/or particulate matter concentration determination.
Measurement of ocular parameters using vibrations induced in the eye
Described is a system, method and apparatus for measuring a vibrational response in an eye for determination of ocular parameters such as intraocular pressure, corneal elasticity and scleral pressure. The method comprises positioning an air jet nozzle to direct an excitation stimulus at a single frequency to the apex of the eye along the optical axis of the eye; positioning a sensor to direct incident light at a fixed position of the eye distinct from the apex of the eye; exciting vibration in the eye with the excitation stimulus; directing incident light from the sensor to the fixed position of the eye; and detecting backscatter light from the eye with the sensor, to measure the vibrational response. Algorithms are used to calculate the ocular pressure from the vibrational response of the cornea or sclera. The method does not require contact with the eye, and is reliable and accurate.
METHOD OF REDUCING FALSE-POSITIVE PARTICLE COUNTS OF AN INTERFERENCE PARTICLE SENSOR MODULE
A method reduces false-positive particle counts detected by an interference particle sensor module, which has a laser and a light detector. The method including: emitting laser light; providing a high-frequency signal during the emission of the laser light, a modulation frequency of the high-frequency signal being between 10-500 MHz; detecting an optical response by the light detector in reaction to the emitted laser light while providing the high-frequency signal, which is arranged such that a detection signal caused by a macroscopic object positioned between a first and second distance is reduced in comparison to a detection signal caused by the macroscopic object at the same position without providing the high-frequency signal. The high-frequency signal is provided to a tuning structure of the particle sensor module which is arranged to modify a resonance frequency of an optical resonator comprised by the laser sensor module upon reception of the high-frequency signal.
PHOTONIC CIRCULATOR FOR A LIDAR DEVICE
A photonic circulator deployed on a chip-scale light-detection and ranging (LiDAR) device includes a first arm that includes a first waveguide that is bonded onto a first member at a first bonding region, and a second arm that includes a second waveguide that is bonded onto a second member at a second bonding region. A first thermo-optic phase shifter is arranged on the first member and collocated with the first waveguide, and a second thermo-optic phase shifter is arranged on the second member and collocated with the second waveguide. The magneto-optic material and the first thermo-optic phase shifter of the first member cause a first phase shift in a first light beam travelling through the first waveguide, and the magneto-optic material and the second thermo-optic phase shifter of the second member cause a second phase shift in a second light beam travelling through the second waveguide.
APPARATUS AND SYSTEM FOR A LIDAR ANTENNA
An apparatus including a light detection and ranging (LiDAR) antenna of an optical phased array includes a silicon-on-insulator substrate including a silicon wire waveguide embedded within the substrate and a grating layer disposed over the substrate. The grating layer includes a silicon nitride layer coating the silicon-on-insulator substrate and including a plurality of etchings formed in a direction perpendicular to a longitudinal axis of the optical phased array and a silicon oxynitride layer coating the silicon nitride layer and filling the etchings. The etchings are relatively thin in the direction of the longitudinal axis of the optical phased array at a first end of the optical antenna and are relatively thick in the direction of the longitudinal axis at a second end. The etchings gradually increase in thickness between the first end of the optical phased array and the second end of the optical antenna.
LIDAR DEVICE
An architecture for a chip-scale optical phased array-based scanning frequency-modulated continuous wave (FMCW) Light-detection and ranging (LiDAR) device is described. The LiDAR device includes a laser, a transmit optical splitter, an optical circulator, photodetectors, and an optical phased array. The laser, the transmit optical splitter, the optical circulator, the photodetectors, and the optical phased array are arranged as a chip-scale package on a single semiconductor substrate. The laser generates a first light beam that is transmitted to the optical phased array aperture via the transmit optical splitter, the optical circulator, and the optical phased array. A fraction of the first light beam is transmitted to the photodetectors via the transmit optical splitter to serve as the optical local oscillator (LO), the aperture of the optical phased array captures a second light beam that is transmitted to the photodetectors via the optical phased array and the optical circulator.
PHOTONIC CIRCULATOR FOR A LIDAR DEVICE
An integrated photonic circulator is described, an application of which may be deployed on a chip-scale light-detection and ranging (LiDAR) device. The photonic circulator includes a micro-ring resonator waveguide, a heating element, first and second bus waveguides, a magneto-optic substrate, a magneto-optic element, a magnetic ring disposed on a photonic substrate, and a silicon substrate. The first and second bus waveguides are coupled to the micro-ring resonator waveguide, and the micro-ring resonator waveguide is affixed onto a first side of the photonic substrate. The magneto-optic element and the magneto-optic substrate are arranged on the micro-ring resonator waveguide, the magnetic ring is affixed to the magneto-optic substrate, the heating element is affixed to the photonic substrate, the photonic substrate is affixed to the silicon substrate, and the magnetic ring is concentric with the micro-ring resonator.
PHOTONIC EDGE COUPLER
A photonic edge coupler includes a slab waveguide and a ridge waveguide. The ridge waveguide includes a silicon wire waveguide, which includes a tapered portion. A first end of the slab waveguide is joined to the ridge waveguide at a junction, and a second end of the slab waveguide forms a first facet. The ridge waveguide defines a longitudinal axis that is associated with a direction of a light signal therein. The first facet is angled at less than 90 degrees relative to the longitudinal axis associated with the direction of the light signal therein. The first facet is disposed opposite to a laser facet associated with a laser waveguide. The longitudinal axis of the ridge waveguide defines a first center point, and the laser facet and the associated laser waveguide define a second center point. The second center point is laterally offset from the first center point.