Abstract: A method for depth mapping includes operating a projector at a first temperature to project a pattern of optical radiation onto a reference plane, capturing a first image of the projected pattern on the reference plane, using the first image and an optical and thermal model of the projector to compute multiple reference images associated with different respective temperatures of the projector. Using the projector, the pattern is projected onto a scene, and a temperature of the projector is measured while projecting the pattern. The method further includes capturing a second image of the projected pattern on the scene, selecting one of the reference images responsively to the measured temperature; and computing a depth map of the scene by comparing the pattern in the second image to the selected one of the reference images.

Abstract: Optical apparatus (38) includes an electro-optical layer (46), contained within a transparent envelope (43, 44) and having an effective local index of refraction at any given location that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes (50) is disposed over a surface of the transparent envelope. Control circuitry (42) is configured to apply voltage waveforms to the excitation electrodes so as to generate across at least a part of the active area of the electro-optical layer a phase modulation profile (60, 63, 64, 65, 66, 67, 70) comprising spatially alternating peaks (61) and troughs (62) separated by phase transitions chosen so as to emulate a Fresnel lens. The troughs have respective phase modulation depths that vary by at least one quarter wavelength at a nominal wavelength of 500 nm across at least the part of the active area of the electro-optical layer that emulates the Fresnel lens.

Abstract: A method for depth mapping includes providing a depth mapping device comprising a projector, which is configured to project a pattern of optical radiation onto a target area over a first field of view about a projection axis, and a camera, which is configured to capture images of the target area within a second field of view, narrower than the first field of view, about a camera axis, which is offset transversely relative to the projection axis. The projector projects the pattern onto first and second planes at first and second distances from the camera, and the camera captures first and second reference images containing first and second parts of the pattern on the first and second planes, respectively. The first and second reference images are combined to produce an extended reference image including both the first and second parts of the pattern.

Abstract: Adaptive spectacles include a spectacle frame and first and second electrically-tunable lenses, mounted in the spectacle frame and having respective focal powers and optical centers that are determined by control voltages applied thereto. Control circuitry is configured to apply the control voltages so as to shift the optical centers of the electrically-tunable lenses responsively to the focal powers of the electrically-tunable lenses.

Abstract: An augmented reality system includes an augmented reality projector that is configured to project an image to an eye of an observer and to allow the observer to view a real scene through the projector. The system further includes first and second electrically-tunable dynamic lenses, which are positioned respectively on opposing first and second sides of the projector, and a controller that is coupled to the projector and the first and second electrically-tunable dynamic lenses. The controller is configured to receive an adjustable accommodation parameter and a specified distance of interest and to set respective first and second refractive powers of the first and second dynamic lenses responsively to the adjustable accommodation parameter and the distance.

Abstract: An optical device includes an electro-optical layer and conductive electrodes disposed over opposing first and second side of the electro-optical layer. Control circuitry is configured to apply at least first control voltage waveforms and second control voltage waveforms between the conductive electrodes so as to generate respective first and second phase modulation profiles in the electro-optical layer, which cause rays of optical radiation that are incident on the device to converge or diverge with respective first and second focal powers, and to change from the first focal power to the second focal power by concurrently applying overshoot control voltages to each of a plurality of the conductive electrodes for different, respective transition periods, followed by application of the second control voltage waveforms.

Abstract: An augmented reality system (70, 100, 140, 180, 190) includes an augmented reality projector (72, 102, 142, 192) that is configured to project an image to an eye (82, 118, 154, 206) of an observer and to allow the observer to view a real scene (80, 116, 164, 204) through the projector. The system further includes first and second electrically-tunable dynamic lenses (74, 76, 104, 106, 144, 146, 194, 196), which are positioned respectively on opposing first and second sides of the projector, and a controller (78, 110, 150, 198) that is coupled to the projector and the first and second electrically-tunable dynamic lenses. The controller is configured to receive an adjustable accommodation parameter and a specified distance of interest and to set respective first and second refractive powers of the first and second dynamic lenses responsively to the adjustable accommodation parameter and the distance.

Abstract: An optical device includes an electro-optical layer and conductive electrodes disposed over opposing first and second side of the electro-optical layer. Control circuitry is configured to apply at least first control voltage waveforms and second control voltage waveforms between the conductive electrodes so as to generate respective first and second phase modulation profiles in the electro-optical layer, which cause rays of optical radiation that are incident on the device to converge or diverge with respective first and second focal powers, and to change from the first focal power to the second focal power by concurrently applying overshoot control voltages to each of a plurality of the conductive electrodes for different, respective transition periods, followed by application of the second control voltage waveforms.

Abstract: An optical device (40) includes an electro-optical layer (46), having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. Conductive electrodes (50, 52) are disposed over opposing first and second side of the electro-optical layer. Control circuitry (26) is configured to apply control voltage waveforms between the conductive electrodes so as to generate a phase modulation profile in the electro-optical layer that causes rays of optical radiation that are incident on the device to converge or diverge with a given focal power, while varying an amplitude of the control voltage waveforms for the given focal power responsively to an angle of incidence of the rays that impinge on the device from a direction of interest.

Abstract: Optical apparatus includes a Fresnel lens (40), including an array of refractive bands (37) bordered by abrupt phase steps (39) of a height selected so as to focus light in different, first and second wavelength ranges from an object plane (35) toward an image plane (36) with a modulation transfer function (MTF) in excess of a predefined threshold, while focusing light in a third wavelength range, intermediate the first and second wavelength ranges, with MTF less than the predefined threshold. A display (32) is configured to generate, at the object plane of the Fresnel lens, an image including first and second pixel colors within the first and second wavelength ranges, respectively.

Abstract: Optical apparatus (38) includes an electro-optical layer (46), contained within a transparent envelope (43, 44) and having an effective local index of refraction at any given location that is determined by a voltage waveform applied across the electro-optical layer at the location. An array of excitation electrodes (50) is disposed over a surface of the transparent envelope. Control circuitry (42) is configured to apply voltage waveforms to the excitation electrodes so as to generate across at least a part of the active area of the electro-optical layer a phase modulation profile (60, 63, 64, 65, 66, 67, 70) comprising spatially alternating peaks (61) and troughs (62) separated by phase transitions chosen so as to emulate a Fresnel lens. The troughs have respective phase modulation depths that vary by at least one quarter wavelength at a nominal wavelength of 500 nm across at least the part of the active area of the electro-optical layer that emulates the Fresnel lens.

Abstract: Optical apparatus includes a Fresnel lens (40), including an array of refractive bands (37) bordered by abrupt phase steps (39) of a height selected so as to focus light in different, first and second wavelength ranges from an object plane (35) toward an image plane (36) with a modulation transfer function (MTF) in excess of a predefined threshold, while focusing light in a third wavelength range, intermediate the first and second wavelength ranges, with MTF less than the predefined threshold. A display (32) is configured to generate, at the object plane of the Fresnel lens, an image including first and second pixel colors within the first and second wavelength ranges, respectively.

Abstract: An augmented reality system (70, 100, 140, 180, 190) includes an augmented reality projector (72, 102, 142, 192) that is configured to project an image to an eye (82, 118, 154, 206) of an observer and to allow the observer to view a real scene (80, 116, 164, 204) through the projector. The system further includes first and second electrically-tunable dynamic lenses (74, 76, 104, 106, 144, 146, 194, 196), which are positioned respectively on opposing first and second sides of the projector, and a controller (78, 110, 150, 198) that is coupled to the projector and the first and second electrically-tunable dynamic lenses. The controller is configured to receive an adjustable accommodation parameter and a specified distance of interest and to set respective first and second refractive powers of the first and second dynamic lenses responsively to the adjustable accommodation parameter and the distance.

Abstract: An optical device (40) includes an electro-optical layer (46), having an effective local index of refraction at any given location within an active area of the electro-optical layer that is determined by a voltage waveform applied across the electro-optical layer at the location. Conductive electrodes (50, 52) are disposed over opposing first and second side of the electro-optical layer. Control circuitry (26) is configured to apply control voltage waveforms between the conductive electrodes so as to generate a phase modulation profile in the electro-optical layer that causes rays of optical radiation that are incident on the device to converge or diverge with a given focal power, while varying an amplitude of the control voltage waveforms for the given focal power responsively to an angle of incidence of the rays that impinge on the device from a direction of interest.