Abstract: A method for operating a display of a virtual reality or augmented reality headset includes determining a direction of movement of a user's eye, estimating a future gaze direction from the determined direction of movement, and rendering an image on the display having higher resolution image data in a region including the estimated gaze direction and lower resolution image data outside of the region including the determined gaze direction. The determining the direction of movement of the user's eye includes illuminating the user's eye with a beam of light emitted by a first laser, receiving, at the first laser, light redirected from the user's eye_such that self-mixing interference occurs within the laser cavity between light generated by the first laser and the light redirected from the user's eye, measuring the self-mixing interference, and determining a direction of movement of the user's eye-from the measured self-mixing interference.

Abstract: A rotary encoder for providing a control signal in dependence upon an angular position of a controller rotatable about an axis of rotation. The rotary encoder includes a component for rotation with said controller about said axis of rotation. The rotary encoder also includes a radiation source and detector arrangement configured to direct radiation towards a target region and generate a detector signal dependent upon radiation reflected from within that target region. The rotary encoder further includes a computer processor configured to process said detector signal to determine a measure of distance or change of distance to a reflecting surface region within said target region, and to use said measure to provide said control signal. The component defines a reflecting surface that passes through said target region such that a reflecting surface region is present within said target region with a distance that varies with the angular position.

Abstract: An eye tracking device for integrating in a frame for mounting to a user's head includes a laser output unit for fixing to the frame. The laser output unit is configured to provide a laser beam for illuminating a cornea of the user's eye when in use. The eye tracking device also includes a receiver unit for fixing to the frame. The receiver unit is configured to receive a reflection of the laser beam and to provide a tracking signal usable for determining a distance or velocity of the cornea. The eye tracking device further includes a processing unit for determining a rotation of the user's eye from the tracking signal.

Abstract: A self-mixing interferometry sensor module for multilayer target detection includes a light emitter, a detector unit and an array of light detectors. The light emitter is operable to emit coherent electromagnetic radiation out of the sensor module, and undergo self-mixing interference (SMI) caused by reflections of the emitted electromagnetic radiation from layers of different depths of a multilayer target to be placed outside the sensor module. The detector unit is operable to generate an SMI output signal indicative of the SMI of the light emitter. Light detectors of the array are operable to generate auxiliary output signals indicative of a distribution of relative reflections of the emitted electromagnetic radiation from layers of different depths.

Abstract: A self-mixing interferometry sensor module includes at least two light emitters of the same type, a detector unit and an electronic processing unit. Each light emitter is operable to emit coherent electromagnetic radiation out of the sensor module and undergo self-mixing interference (SMI) caused by reflections of the emitted electromagnetic radiation from an external object outside the sensor module. The detector unit is operable to generate output signals indicative of the SMI of the light emitters, respectively. The electronic processing unit is operable to generate a difference signal from the output signals indicative of a movement of the external object.

Abstract: In an embodiment a includes providing the self-mixing interferometer including a laser diode, emitting laser light and receiving a reflected portion of the emitted laser light to modulate an optical power of the laser diode, the interferometer having a transfer function of the optical power of the laser diode having fringes, locking a phase of the laser light to at least one of the fringes to obtain an operating point, generating an interrogation signal to change a wavelength of the laser light to obtain a response signal indicative of an offset of the operating point from a desired operating point and generating a compensation signal depending on the response signal.

Abstract: An optical device includes a display and an optical sensor. The display includes display circuitry. The optical sensor is arranged behind the display. The optical sensor includes an emitter for emitting light through the display and a receiver for receiving light reflected back through the display. An absorption of the display is wavelength dependent and the absorption of the display is 50% at a first wavelength. The emitter is configured to emit light at a second wavelength greater than the first wavelength.

Abstract: An optical device for proximity sensing includes a tunable laser source for emitting laser light. The tunable laser source includes a vertical cavity surface emitting laser, VCSEL. The VCSEL includes a microelectromechanical system, MEMS, for tuning the VCSEL by changing a length of a laser cavity of the VCSEL and includes a receiver configured to receive laser light emitted by the tunable laser source and reflected from an object.

Abstract: A method for operating a display of a virtual reality or augmented reality headset includes determining a direction of movement of a user's eye, estimating a future gaze direction from the determined direction of movement, and rendering an image on the display having higher resolution image data in a region including the estimated gaze direction and lower resolution image data outside of the region including the determined gaze direction. The determining the direction of movement of the user's eye includes illuminating the user's eye with a beam of light emitted by a first laser, receiving, at the first laser, light redirected from the user's eye_such that self-mixing interference occurs within the laser cavity between light generated by the first laser and the light redirected from the user's eye, measuring the self-mixing interference, and determining a direction of movement of the user's eye-from the measured self-mixing interference.

Abstract: An eye tracking device for integrating in a frame for mounting to a user's head includes a laser output unit for fixing to the frame. The laser output unit is configured to provide a laser beam for illuminating a cornea of the user's eye when in use. The eye tracking device also includes a receiver unit for fixing to the frame. The receiver unit is configured to receive a reflection of the laser beam and to provide a tracking signal usable for determining a distance or velocity of the cornea. The eye tracking device further includes a processing unit for determining a rotation of the user's eye from the tracking signal.

Abstract: An optical device includes a display and an optical sensor. The display includes display circuitry. The optical sensor is arranged behind the display. The optical sensor includes an emitter for emitting light through the display and a receiver for receiving light reflected back through the display. An absorption of the display is wavelength dependent and the absorption of the display is 50% at a first wavelength. The emitter is configured to emit light at a second wavelength greater than the first wavelength.

Abstract: An apparatus may provide a control signal based on an axial position of a controller displaceable along an axis. The apparatus may include a component for displacement with said controller along said axis, a radiation source and detector arrangement configured to direct radiation towards a target region and generate a detector signal dependent upon radiation reflected from within that target region, and a computer processor configured to process said detector signal to determine a measure of distance or change of distance to a reflecting surface region within said target region, and to use said measure to provide said control signal. The component may define a reflecting surface that passes through said target region such that a reflecting surface region is present within said target region with a distance that varies with the axial position of the component along said axis.

Abstract: An electro-acoustic transducer includes a membrane, a substrate, and at least one optical device. The at least one optical device is coupled to the substrate for sensing an excursion or velocity of the membrane. The at least one optical device is disposed on an opposite side of the substrate to the membrane.

Abstract: An optical device includes a display and an optical sensor. The display includes display circuitry. The optical sensor is arranged behind the display. The optical sensor includes an emitter for emitting light through the display and a receiver for receiving light reflected back through the display. An absorption of the display is wavelength dependent and the absorption of the display is 50% at a first wavelength. The emitter is configured to emit light at a second wavelength greater than the first wavelength.

Abstract: An electro-acoustic transducer includes a membrane and at least one laser. The at least one laser is configured to emit radiation toward the membrane such that radiation emitted by the at least one laser is reflected from the membrane back toward the at least one laser to produce a self-mixing interference effect corresponding to an excursion or velocity of the membrane.

Abstract: A self-mixing interferometry sensor module, comprising a light emitter (LE), a detector unit (DU) and an optical element (OE), wherein the light emitter (LE) is operable to emit coherent electromagnetic radiation towards an external object (ET) to be placed outside the sensor module and undergo self-mixing interference, SMI, caused by reflections of the emitted electromagnetic radiation from the external object back inside the sensor module. The detector unit (DU) is operable to generate output signals indicative of an optical power output of the light emitter (LE) due to the SMI. The optical element (OE) is aligned with respect to the light emitter (LE) such that a first fraction of electromagnetic radiation is directed towards the external target (ET) or the light emitter (LE) and a second fraction of electromagnetic radiation is directed towards the detector unit (DU). An optical power ratio determined by the first and second fractions meets a pre-determined value.

Abstract: A self-mixing interferometry sensor module, comprising a light emitter (LE), a detector unit (DU) and an optical element (OE), wherein the light emitter (LE) is operable to emit coherent electromagnetic radiation towards an external object (ET) to be placed outside the sensor module and undergo self-mixing interference, SMI, caused by reflections of the emitted electromagnetic radiation from the external object back inside the sensor module. The detector unit (DU) is operable to generate output signals indicative of an optical power output of the light emitter (LE) due to the SMI. The optical element (OE) is aligned with respect to the light emitter (LE) such that a first fraction of electromagnetic radiation is directed towards the external target (ET) or the light emitter (LE) and a second fraction of electromagnetic radiation is directed towards the detector unit (DU). An optical power ratio determined by the first and second fractions meets a pre-determined value.

Abstract: A rotary encoder for providing a control signal in dependence upon an angular position of a controller rotatable about an axis of rotation. The rotary encoder includes a component for rotation with said controller about said axis of rotation. The rotary encoder also includes a radiation source and detector arrangement configured to direct radiation towards a target region and generate a detector signal dependent upon radiation reflected from within that target region. The rotary encoder further includes a computer processor configured to process said detector signal to determine a measure of distance or change of distance to a reflecting surface region within said target region, and to use said measure to provide said control signal. The component defines a reflecting surface that passes through said target region such that a reflecting surface region is present within said target region with a distance that varies with the angular position.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active layer are disclosed. In particular, the semiconductor devices have a dilute nitride active layer with a bandgap within a range from 0.7 eV and 1 eV. Photodetectors comprising a dilute nitride active layer have a responsivity of greater than 0.6 A/W at a wavelength of 1.3 ?m.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active region are disclosed. In particular, the semiconductor devices have a dilute nitride active region with at least two bandgaps within a range from 0.7 eV and 1.4 eV. Photodetectors comprising a dilute nitride active region with at least two bandgaps have a reduced dark current when compared to photodetectors comprising a dilute nitride active region with a single bandgap equivalent to the smallest bandgap of the at least two bandgaps.