Abstract: An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.

Abstract: The inventive optical fiber coupler array is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser.

Abstract: The invention provides an LED including a first-type semiconductor layer, an emitting layer, a second-type semiconductor layer, a first electrode, a second electrode, a Bragg reflector structure, a conductive layer and insulation patterns. The first electrode and the second electrode are located on the same side of the Bragg reflector structure. The conductive layer is disposed between the Bragg reflector structure and the second-type semiconductor layer. The insulation patterns are disposed between the conductive layer and the second-type semiconductor layer. Each insulating layer has a first surface facing toward the second-type semiconductor layer, a second surface facing away from the second-type semiconductor layer, and an inclined surface. The inclined surface connects the first surface and the second surface and is inclined with respect to the first surface and the second surface.

Abstract: A light-emitting device including at least one light-emitting unit, a wavelength conversion adhesive layer, and a reflective protecting element is provided. The light-emitting unit has an upper surface and a lower surface opposite to each other. The light-emitting unit includes two electrode pads, and the two electrode pads are located on the lower surface. The wavelength conversion adhesive layer is disposed on the upper surface. The wavelength conversion adhesive layer includes a low-concentration fluorescent layer and a high-concentration fluorescent layer. The high-concentration fluorescent layer is located between the low-concentration fluorescent layer and the light-emitting unit. The width of the high-concentration fluorescent layer is WH. The width of the low-concentration fluorescent layer is WL. The width of the light-emitting unit is WE. The light-emitting device further satisfies the following inequalities: WE<WL, WH<WL and 0.8<WH/WE?1.2.

Abstract: A semiconductor laser diode includes multiple layers stacked along a first direction, in which the multiple layers include: a first multiple of semiconductor layers; an optical waveguide on the first multiple of semiconductor layers, in which the optical waveguide includes a semiconductor active region for generating laser light, and in which the optical waveguide defines a resonant cavity having an optical axis; and a second multiple of semiconductor layers on the optical waveguide region, in which a resistivity profile of at least one layer of the multiple layers varies gradually between a maximum resistivity and a minimum resistivity along a second direction extending orthogonal to the first direction, in which a distance between the maximum resistivity and the minimum resistivity is greater than at least about 2 microns.

Abstract: A method of forming an optical device includes forming a waveguide mask on a device precursor. The device precursor includes a waveguide positioned on a base. The method also includes forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base. The method also includes removing a portion of the base while the facet mask protects a facet of the waveguide. The portion of the base that is removed can be removed such that a recess is defined in the base and/or a shelf is defined on the device precursor. A light source such as an optical fiber or laser can be received in the recess and/or positioned over the shelf such that the light source is optically aligned with the facet of the waveguide.

Abstract: Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.

Abstract: A laser diode includes a semiconductor structure of a lower Bragg reflector layer, an active region, and an upper Bragg reflector layer. The upper Bragg reflector layer includes a lasing aperture having an optical axis oriented perpendicular to a surface of the active region. The active region includes a first material, and the lower Bragg reflector layer includes a second material, where respective lattice structures of the first and second materials are independent of one another. Related laser arrays and methods of fabrication are also discussed.

Abstract: Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene.

Abstract: An optical system includes a laser die that includes a gain medium and multiple laser waveguides that are each configured to guide a different laser light signal through the gain medium. Each of the laser waveguides outputs a laser light signal at a wavelength. The laser waveguides are arranged in multiple candidate groups. Each candidate group includes multiple laser waveguides. The wavelength spacing of the laser waveguides is the same or substantially the same in different candidate groups.

Abstract: A laser array includes a plurality of laser diodes arranged and electrically connected to one another on a surface of a non-native substrate. Respective laser diodes of the plurality of laser diodes have different orientations relative to one another on the surface of the non-native substrate. The respective laser diodes are configured to provide coherent light emission in different directions, and the laser array is configured to emit an incoherent output beam comprising the coherent light emission from the respective laser diodes. The output beam may include incoherent light having a non-uniform intensity distribution over a field of view of the laser array. Related devices and fabrication methods are also discussed.

Abstract: Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.

Abstract: A low noise, single mode laser includes a semiconductor gain element generating light and having a highly reflective first end forming a first end of a laser cavity. The gain element may be monolithically or discretely integrated with, or distinct from, and coupled to a waveguide comprised of a low loss material with a refractive index ‘n’ greater than 3. The waveguide includes a Bragg grating forming the second end of the laser cavity. A cavity phase control section may be provided between the gain element and the Bragg grating. Two photodetector monitors provide a feedback signal for locking the light from the gain element to a specific wavelength on the Bragg grating reflection spectrum by varying at least one of the cavity phase control section and the gain element bias current. The Bragg grating may have a physical length larger than 10 mm and that occupies at least 50% of the optical length of the external cavity.

Abstract: A laser array includes a plurality of laser emitters arranged in a plurality of rows and a plurality of columns on a substrate that is non-native to the plurality of laser emitters, and a plurality of driver transistors on the substrate adjacent one or more of the laser diodes. A subset of the plurality of laser emitters includes a string of laser emitters that are connected such that an anode of at least one laser emitter of the subset is connected to a cathode of an adjacent laser emitter of the subset. A driver transistor of the plurality of driver transistors is configured to control a current flowing through the string.

Abstract: The present invention is directed to an optical fiber grating having a core, that is capable of controlling the light signal transmission therethrough by causing at least one of: at least one spectral peak, and/or at least one spectral dip in its core light transmission spectrum, corresponding to at least one predetermined wavelength. The inventive optical fiber diffraction grating comprises at least one longitudinally positioned structural element of a predetermined geometric profile and that is configured for diffracting a portion of the transmitted light signal at at least one predefined wavelength thereof, from at least one core mode into at least one of: at least one cladding mode and/or at least one radiating mode. Various embodiments of a number of novel techniques for fabrication of the inventive optical fiber diffraction grating are provided, inclusive of a novel technique for fabricating the inventive grating from a single material.

Abstract: A laser including: a gain chip; an external cavity incorporating a Bragg grating; and a baseplate; wherein a first end of the gain chip has a high reflectivity facet forming a first end of the laser cavity; a second end of the gain chip has a low reflectivity facet; and a second part of the external cavity comprises a Bragg grating, supported by the baseplate, the temperature of the baseplate being maintained through a feedback loop; wherein the optical length of the external cavity is at least an order of magnitude greater than the optical length of the gain chip; wherein the Bragg grating is physically long and occupies a majority of the length of the external cavity and is apodized to control the sidemodes of the grating reflection.

Abstract: A wide field of view night vision system is described. The system comprises a head attachment apparatus configured to attach to a user's head and a night vision subsystem. The night vision subsystem comprises one or more night vision image sensors attached to the head attachment apparatus. Each sensor receives input light and produces a digital image of the input light. A processor processes the digital image(s) to produce a wide-field image. The wide-field image spans at least 60 degrees of a user's horizontal field of view. A display and eyepiece attached to the head attachment apparatus receives and displays the wide-field image. The eyepiece is positionable between the display and the user's eye to image the wide-field image into the user's eye.

Abstract: A laser including: a gain chip; an external cavity incorporating a Bragg grating; and a baseplate; wherein a first end of the gain chip has a high reflectivity facet forming a first end of the laser cavity; a second end of the gain chip has a low reflectivity facet; and a second part of the external cavity comprises a Bragg grating, supported by the baseplate, the temperature of the baseplate being maintained through a feedback loop; wherein the optical length of the external cavity is at least an order of magnitude greater than the optical length of the gain chip; wherein the Bragg grating is physically long and occupies a majority of the length of the external cavity and is apodized to control the sidemodes of the grating reflection.

Abstract: A nitrogen-containing semiconductor device including a first type doped semiconductor layer, a multiple quantum well layer and a second type doped semiconductor layer is provided. The multiple quantum well layer includes barrier layers and well layers, and the well layers and the barrier layers are arranged alternately. The multiple quantum well layer is located between the first type doped semiconductor layer and the second type doped semiconductor layer, and one of the well layers of the multiple quantum well layer is connected to the second type doped semiconductor layer.

Abstract: An instrument and method for analyzing a gas leak. The instrument can obtain a time series of spectra from a scene. The instrument can compare spectra from different times to determine a property of a gas cloud within the scene. The instrument can estimate the column density of the gas cloud at one or more locations within the scene. The instrument can estimate the total quantity of gas in the cloud. The instrument can estimate the amount of gas which has left the field of view of the instrument. The instrument can also estimate the amount of gas in the cloud which has dropped below the sensitivity limit of the instrument.