The present invention relates to accurately determining a contour of a depolarizing region.

An image processing apparatus extracts a depolarizing region in a polarization-sensitive tomographic image of a subject's eye, and detects, in a tomographic intensity image of the subject's eye, a region corresponding to the extracted depolarizing region. The tomographic intensity image corresponds to the polarization-sensitive tomographic image,

An eye-tracking device includes an optical device that includes a light source with an optical cavity and a light sensor. The light source is positioned to output coherent light toward an eye of a user and receive at least a portion of the coherent light back from the eye of the user as feedback light. The feedback light enters the optical cavity and causes modulation of an intensity of the coherent light. The light sensor is optically coupled with the light source for detecting the modulated intensity of the coherent light and generating one or more signals based on the detected intensity of the coherent light. The eye-tracking device also includes one or more processors that are coupled to the optical device for determining, from the one or more signals, movement information of the eye. A method of detecting movement of an eye using the eye-tracking device is also disclosed.

Aspects of the present disclosure describe Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination. In illustrative configurations, systems, methods, and structures according to the present disclosure employ a two stage modulation arrangement providing short interrogator pulses resulting in a greater number of sensing data points and reduced effective sectional length. The increased number of data points are used to mitigate Rayleigh fading via a spatial combining process, multi-location-beating combining (MLBC) which uses weighted complex-valued DAS beating results from neighboring locations and aligns phase signals of each of the locations, before combining them to produce a final DAS phase measurement. Since Rayleigh scattering is a random statistic, the MLBC process allows capture of different statics from neighboring locations with correlated vibration/acoustic signal. The combined DAS results minimize a total Rayleigh fade, in both dynamic fading and static fading scenarios.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

A device includes a first component, a second component having a reconfigurable distance from the first component, an optical element, an SMI sensor, and a processor. The optical element has a fixed relationship with respect to the first component, and has a known optical thickness between a first surface and a second surface of the optical element. The SMI sensor has a fixed relationship with respect to the second component, and has an electromagnetic radiation emission axis that intersects the first and second surfaces of the optical element. The processor is configured to identify disturbances in an SMI signal generated by the SMI sensor, relate the disturbances to the known optical thickness of the optical element, and to determine a distance between the first and second components using the SMI signal and the relationship of the disturbances to the known optical thickness of the optical element.

A laser sensor includes a laser source configured to emit a laser beam, and optics configured to project the laser beam as a one- or two-dimensional patterned laser beam onto an object to be examined, such that a distance of the patterned laser beam from the laser source varies along the patterned laser beam projected on the object. The laser sensor further includes a detector configured to determine a self-mixing interference signal generated by laser light of the patterned laser beam reflected from the object back into the laser source, and circuitry configured to analyze a spectrum of the self-mixing interference signal and extract from the spectrum of the self-mixing interference signal multiple frequencies that are indicative of at least one of the following: multiple distances along the patterned laser beam from the laser source, or multiple velocities along the patterned laser beam with respect to the laser source.

A method of estimating a velocity of an object using an SMI sensor. The method includes driving a light emitter of the SMI sensor with a chirped waveform. The chirped waveform includes a first chirp and a second chirp separated by a first time interval, and a third chirp separated from the second chirp by a second time interval. The method also includes deriving a frequency-based velocity from an output of the SMI sensor; generating a first comb of possible velocities in response to analyzing an output of the SMI sensor generated in response to the first chirp and the second chirp; generating a second comb of possible velocities in response to analyzing an output of the SMI sensor generated in response to the second chirp and the third chirp; and determining a velocity of the object using the first comb, the second comb, and the frequency-based velocity.

Disclosed herein are electronic devices having touch input surfaces. A user's touch input or press on the touch input surface is detected using a set of lasers, such as vertical-cavity surface-emitting lasers (VCSELs) that emit beams of light toward the touch input surface. The user's touch causes changes in the self-mixing interference within the VCSEL of the emitted light with reflected light, such as from the touch input surface. Deflection and movement (e.g., drag motion) of the user's touch is determined from detected changes in the VCSELs' operation due to the self-mixing interference.

Disclosed herein are wearable devices, their configurations, and methods of operation that use self-mixing interferometry signals of a self-mixing interferometry sensor to recognize user inputs. The user inputs may include voiced commands or silent gesture commands. The devices may be wearable on the user's head, with the self-mixing interferometry sensor configured to direct a beam of light toward a location on the user's head. Skin deformations or vibrations at the location may be caused by the user's speech or the user's silent gestures and recognized using the self-mixing interferometry signal. The self-mixing interferometry signals may be used for bioauthentication and/or audio conditioning of received sound or voice inputs to a microphone.

A light source of a self-mixed interferometer (SMI) emits infrared light. The infrared light is directed to an eyebox location with the scanning module by scanning the infrared light into a waveguide. Feedback infrared light is measured by a light sensor of the SMI.