Abstract: A miniature structured light illuminator is provided. The miniature structured light illuminator uses a semiconductor surface emitting array including VCSEL or RC-LED array and an array of microlens elements to generate a wide range of structured light illumination patterns. The emission beam from a surface emitter array may be selectively directed, steered, focused or expanded, by applying a lateral displacement of the microlens array, such that centers of the emission beam and microlens array are misaligned. Emitted beams may be directed through small optical components to project the structured light pattern to a distant plane. The surface emitting arrays may be configured in addressable form to be activated separately for continuous or pulsed operation with very fast pulses having <100 ps risetime. A compact structured light illuminator module with projection optics is provided in very small physical size (˜6×6×3 mm3) suitable to configure in a handheld device.

Abstract: A set of VCSEL fabrication methods has been invented which enhance the performance and long time reliability of VCSEL devices and arrays of devices. Wafer bow caused by growing a large number of epitaxial layers required to fabricate VCSEL device generates strain and results in bowing/warping of the device wafer. The stress so generated is eliminated by applying a stress compensation layer on the substrate to a surface opposite to the epitaxial layer surface. New oxidation equipment designs and process parameters are described which produce more precision apertures and reduce stress in the VCSEL device. An ultrathin fabrication procedure is described which enables high power VCSELs to be made for high power operation at many different wavelengths. A low temperature electrical contacting process improves VCSEL long term reliability.

Abstract: A miniature structured light illuminator is provided. The miniature structured light illuminator uses a semiconductor surface emitting array including VCSEL or RC-LED array and an array of microlens elements to generate a wide range of structured light illumination patterns. The emission beam from a surface emitter array may be selectively directed, steered, focused or expanded, by applying a lateral displacement of the microlens array, such that centers of the emission beam and microlens array are misaligned. Emitted beams may be directed through small optical components to project the structured light pattern to a distant plane. The surface emitting arrays may be configured in addressable form to be activated separately for continuous or pulsed operation with very fast pulses having <100 ps risetime. A compact structured light illuminator module with projection optics is provided in very small physical size (˜6×6×3 mm3) suitable to configure in a handheld device.

Abstract: A structured light source comprising VCSEL arrays is configured in many different ways to project a structured illumination pattern into a region for 3 dimensional imaging and gesture recognition applications. One aspect of the invention describes methods to construct densely and ultra-densely packed VCSEL arrays with to produce high resolution structured illumination pattern. VCSEL arrays configured in many different regular and non-regular arrays together with techniques for producing addressable structured light source are extremely suited for generating structured illumination patterns in a programmed manner to combine steady state and time-dependent detection and imaging for better accuracy. Structured illumination patterns can be generated in customized shapes by incorporating differently shaped current confining apertures in VCSEL devices.

Abstract: An apparatus and a method are provided for 3-D imaging and scanning using a 2-D planar VCSELs source configured as a lightfiled optical source. VCSELs are configured in different 2-D spatial arrangements including single VCSEL, or preferably a group, cluster, or array each to be operated effectively as an independent VCSEL array source. A set of microlens and an imaging lens positioned at a pre-determined distance collimates radiation from each VCSEL array source to a set of parallel beams. The parallel beams from different VCSEL array sources generated in a rapid pre-determined timing sequence provide scanning beams to illuminate an object. The radiation reflected from the object is analyzed for arrival time, pulse shape, and intensity to determine a comprehensive set of distance and intensity profile of the object to compute a 3-D image.

Abstract: An apparatus and a method are provided for 3-D imaging and scanning using a 2-D planar VCSELs source configured as a lightfiled optical source. VCSELs are configured in different 2-D spatial arrangements including single VCSEL, or preferably a group, cluster, or array each to be operated effectively as an independent VCSEL array source. A set of microlens and an imaging lens positioned at a pre-determined distance collimates radiation from each VCSEL array source to a set of parallel beams. The parallel beams from different VCSEL array sources generated in a rapid pre-determined timing sequence provide scanning beams to illuminate an object. The radiation reflected from the object is analyzed for arrival time, pulse shape, and intensity to determine a comprehensive set of distance and intensity profile of the object to compute a 3-D image.

Abstract: A new VCSEL design is presented to achieve high output power and high brightness with a strong selection of a linear polarization state in high speed pulsing operation. Higher output power is achieved by including multiple gain segments in tandem, in the gain region. To achieve single mode operation with high output power, an extended cavity three reflector design is presented. High degree of polarization selectivity is achieved by a linear grating deployed with the third reflector, such that lasing is allowed only in a preferred linear polarization state. A polarization selective reflector including a linear grating is designed to impart strong polarization selectivity for a preferred linear polarization state. The polarization selective reflector used as the third reflector in an extended cavity VCSEL device, exhibits strong polarization selection for a preferred linear polarization state during high speed pulsing including in the gain switching resonance regime.

Abstract: An apparatus and a method are provided for 3-D proximity sensing, imaging and scanning using a 2-D planar VCSEL array source using reflected radiation from an object being detected. An important aspect of the apparatus is a compact high power optical source and in particular, an optical source comprising a plurality of VCSELs to illuminate the object. VCSELs in the optical source are configured in different 2-D planar arrangements, such that the optical source may be used in many different modes to adapt to different sensing, imaging and scanning requirement suited for different environments including one where shape, size and illumination mode require to be altered dynamically. When used in different modes of operation the apparatus provides a comprehensive set of measured distance and intensity profile of the object to compute a 3-D image.

Abstract: A set of VCSEL fabrication methods has been invented which enhance the performance and long time reliability of VCSEL devices and arrays of devices. Wafer bow caused by growing a large number of epitaxial layers required to fabricate VCSEL device generates strain and results in bowing/warping of the device wafer. The stress so generated is eliminated by applying a stress compensation layer on the substrate to a surface opposite to the epitaxial layer surface. New oxidation equipment designs and process parameters are described which produce more precision apertures and reduce stress in the VCSEL device. An ultrathin fabrication procedure is described which enables high power VCSELs to be made for high power operation at many different wavelengths. A low temperature electrical contacting process improves VCSEL long term reliability.

Abstract: VCSEL arrays with planar electrical contacts readily adaptable for surface mounting are provided. Monolithic VCSEL arrays are configured in array patterns on two and three-dimensional surfaces for configuring optical illuminator modules. Illuminator modules are easily expandable by increasing the array size or by modularly arranging more arrays with or without a transparent substrate, in different shapes by tiling array modules monolithically on a common substrate, or by tiling small modules. The surface mountable illuminator modules are easily assembled on a thermally conductive surface that may be air or liquid cooled for efficient heat dissipation. Array modules may be integrated with other electronic circuits such as current drivers, sensors, controllers, processors, etc.

Abstract: VCSEL arrays with planar electrical contacts readily adaptable for surface mounting are provided. Monolithic VCSEL arrays are configured in array patterns on two and three-dimensional surfaces for configuring optical illuminator modules. Illuminator modules are easily expandable by increasing the array size or by modularly arranging more arrays with or without a transparent substrate, in different shapes by tiling array modules monolithically on a common substrate, or by tiling small modules. The surface mountable illuminator modules are easily assembled on a thermally conductive surface that may be air or liquid cooled for efficient heat dissipation. Array modules may be integrated with other electronic circuits such as current drivers, sensors, controllers, processors, etc.

Abstract: Touch screen sensor systems that incorporate VCSELs or VCSEL arrays to provide illumination beams for sensing the position of objects such as a finger or stylus in a two dimensional space is provided. Normally the touch sensor is used with a display screen so that objects in the display screen are identified by positioning a finger or stylus at the object's position. The invention describes improved illumination methods using VCSELs that realize higher resolution in position sensing. VCSELs can also be integrated with detectors on a common substrate which provides both illumination and detection functions for the touch sensor system. Different methods to suitably couple light from VCSEL arrays directly, or through guided light paths such as fibers and waveguide arrays are provided to configure a touch sensor in different applications.

Abstract: A wavelength locker comprising a semiconductor or air gap etalon is used to monitor and maintain the output wavelength of a coherent radiation source. Said etalon may be fabricated from a commercially available silicon wafer, with individual regions of the wafer, each functioning as a separate etalon, etched or otherwise processed to produce different thicknesses. Illumination by the coherent radiation source generated transmitted signal intensities that are detected and processed to determine the output wavelength of the coherent radiation source. A wavelength tuner is then used to maintain or vary the output wavelength based on continuous measurements of etalon signal intensity.

Abstract: A vertical cavity surface emitting laser (VCSEL) device with improved power and beam characteristics. The VCSEL device contains one VCSEL or an array of VCSELs. Each VCSEL has a corresponding integrated microlens, and a heat sink is attached to the device side of the VCSEL device. The heat sink allows improved heat dissipation, and therefore provides improved power characteristics of the VCSEL device output laser beam. The microlens or microlens array allows easier and more compact focussing of the VCSEL device output laser beam. The VCSEL device can be used in a variety of optical systems, and its improved power and focusing characteristics provide a compact, low power, low cost laser system.

Abstract: A wavelength locker comprising a semiconductor or air gap etalon is used to monitor and maintain the output wavelength of a coherent radiation source. Said etalon may be fabricated from a commercially available silicon wafer, with individual regions of the wafer, each functioning as a separate etalon, etched or otherwise processed to produce different thicknesses. Illumination by the coherent radiation source generated transmitted signal intensities that are detected and processed to determine the output wavelength of the coherent radiation source. A wavelength tuner is then used to maintain or vary the output wavelength based on continuous measurements of etalon signal intensity.

Abstract: Photomasks (11, 12) are aligned on opposite sides of a wafer by directing light beams through zone plates (13 A-C) in one photomask and through aligned transparent slits (14 A-C) on the other photomask. Simulantaneous detection of the beams by photodetectors (18 A-C) indicates alignment. A method for obtaining precise centering by scanning the slits with the beams, sampling light transmitted through the slits, and fitting the samples to a parabola by the use of a computer (27) is also described.

Abstract: A photomask (30) used to form patterns on a resist coated semiconductor wafer is comprised of a transparent baseplate (31) having a thin metallic pattern (32) thereon; a transparent, planar coverplate (33) in intimate contact with the patterned baseplate (31) and an index matching fluid (34) interposed therebetween.

Abstract: A photomask (30) used to form patterns on a resist coated semiconductor wafer is comprised of a transparent baseplate (31) having a thin metallic pattern (32) thereon; a transparent, planar coverplate (33) in intimate contact with the patterned baseplate (31) and an index matching fluid (34) interposed therebetween.

Abstract: A narrow laser beam (16) scans a clad optical fiber preform (10) with a narrow, parallel scanning beam of coherent light and the deflection angle (.theta.) thereof measured as the beam exits the preform. The deflection angles (.theta.) of the scanning beam (16) are measured and compared to theoretical or empirically developed deflection angle scans of preforms having known parameters to determine the parameters of the preform. The deflection angle (.theta.) is plotted versus the incident beam position (d) and that plot is integrated to provide a curve (47) that is compared to theoretically developed plots having known parameters to determine parameters of the fiber preform such as refractive index gradient power, .gamma., and the refractive index ratio, .DELTA..

Abstract: An intensity-type optical spatial filtering system is arranged to form a composite visual image of all nonperiodic errors in a photomask or other two-dimensional pattern which contains an array of regularly spaced, normally identical elements. A coherent beam of light is diffracted by the pattern and focused onto a transparency having a second array of discrete opaque regions spaced by a distance inversely proportional to the element spacing on the pattern. The focused light, spatially modulated by the transparency, is reimaged and projected in enlarged form onto a display screen.