A wearable electronic device including a housing that is worn by a user and a SMI sensor contained within the housing. The SMI sensor may include an emitter that outputs coherent light toward the skin of a user when the housing is worn by the user. The SMI sensor may also include a detector that detects a portion of the coherent light reflected towards the sensor and generates electrical signals that indicate displacements of the skin based on the portion of coherent light received at the detector. The housing may include a transmitter that is operatively coupled with the SMI sensor and is configured to transmit physiological data to a receiving device based on electrical signals output from the SMI sensor.

An optical proximity sensor includes a first vertical cavity surface-emitting laser configured for self-mixing interferometry to determine distance to and/or velocity of an object. The optical proximity sensor also includes a second vertical cavity surface-emitting laser configured for self-mixing interferometry to determine whether any variation in a fixed distance has occurred. The optical proximity sensor leverages output from the second vertical cavity surface-emitting laser to calibrate output from the second vertical cavity surface-emitting laser to eliminate and/or mitigate environmental effects, such as temperature changes.

A laser sensor module includes a first laser source configured to emit first modulated light, the first modulated light being modulated laser light. The laser sensor module further includes circuitry configured to drive the first laser source with a first modulated driving current to cause the first laser source to emit the modulated laser light, a detector configured to detect the modulated laser light, which induces a photocurrent with variations resulting from modulation of the modulated laser light, and a second laser source configured to emit second modulated light. The circuitry is further configured to drive the second laser source with a second modulated driving current to cause the second laser source to emit the second modulated light. The detector is configured to detect the second modulated light. The circuitry is configured to adapt the amplitude of the second modulated driving current to induce a contribution to the photocurrent.

Self-mixed interferometer (SMI) devices and techniques are described for measuring depth and/or velocity of objects. The SMI devices and techniques may be used for eye-tracking. A light source of an SMI sensor emits coherent light that is directed to a target location with a scanning module. One or more SMI signals are measured. The one or more SMI signals are generated by the SMI sensor in response to feedback light received from the target location. The feedback light is a portion of the coherent light that illuminated the target location.

An optical sensor system including a semiconductor substrate; a self-mixing interferometry (SMI) sensor formed on the semiconductor substrate and including a semiconductor laser having a resonant cavity; and an array of photodetectors formed on the semiconductor substrate. The SMI sensor is configured to generate an SMI signal responsive to a retro-reflection of electromagnetic radiation emitted by the semiconductor laser and received into the resonant cavity. The array of photodetectors is configured to generate a set of angular-resolved scatter signals responsive to a scatter of the electromagnetic radiation emitted by the semiconductor laser.

A method and an apparatus for measuring the properties of a liquid that exploit the power modulation a laser light beam undergoes due to the retro-reflection of the laser light beam itself towards the laser cavity from which the laser is generated when this laser light is directed towards a transparent conduit through which the liquid for which the properties are to be measured flows, where this power modulation is detected by at least one photodiode arranged downstream of the transparent conduit.

The invention relates to a device and to a method for measuring an object that moves in a direction of movement along a movement axis, wherein the device has a first sensor arrangement having a first SMI sensor and a second SMI sensor, wherein the SMI sensors irradiate measurement light beams in opposite directions along a movement axis. A control and evaluation unit is configured to receive first and second measured signals, to determine a speed of the object along the movement axis from at least one of the measured signals, to detect a first characteristic change of the second measured signal, a first characteristic change of the first measured signal, and a second characteristic change of the first measured signal, and to determine an object length of the object along the movement axis.

An optical proximity sensor includes an optical path extender that extends an optical path length of the optical proximity sensor without a corresponding extension of a geometric path length of the optical proximity sensor. The optical path extender may be a high-refractive index material positioned along the optical path through the optical proximity sensor. The optical path extender may include one or more redirection features configured to change a direction of the light traveling within the optical proximity sensor. The optical path extender may include a photonic component configured to simulate an extension of the geometric path within an optical proximity sensor by applying a momentum-dependent transfer function to the light traveling through it.

Self-mixed interferometer (SMI) devices and techniques are described for measuring depth and/or velocity of objects. The SMI devices and techniques may be used for eye-tracking. A light source of an SMI sensor emits coherent light that is directed to a target location with a scanning module. One or more SMI signals are measured. The one or more SMI signals are generated by the SMI sensor in response to feedback light received from the target location. The feedback light is a portion of the coherent light that illuminated the target location.

An electronic device is described. The electronic device includes a housing, a set of one or more SMI sensors attached to the housing, and a processor. The set of one or more SMI sensors includes a set of one or more electromagnetic radiation emitters having a set of one or more resonant cavities and configured to emit a set of one or more beams of electromagnetic radiation. The set of one or more SMI sensors also includes a set of one or more detectors configured to generate indications of self-mixing within the set of one or more resonant cavities. The processor is configured to characterize, using the indications of self-mixing, an optical field speckle of a target. The processor is also configured to characterize, using the characterization of the optical field speckle, a surface quality of the target.