Abstract: A light emitting device is provided including a switching element. The light emitting device includes a light emitting unit having a plurality of nanostructures that can emit lights with injection of currents, and a transistor provided in correspondence with the light emitting unit and controlling amounts of the currents injected in the nanostructures.

Abstract: Embodiments of the disclosure pertain to a system for transferring an optical signal from one photonics chip or integrated circuit (PIC) to another. The system includes a first PIC having (i) an optical emitter or optical transmission mechanism and (ii) a focusing mirror thereon, and a second PIC having an optical receiver and a reflecting mirror thereon. The reflecting mirror is configured to reflect light transmitted by the optical emitter or optical transmission mechanism back to the first PIC. The focusing mirror is configured to (i) further reflect the light reflected by the reflecting mirror and (ii) focus the further reflected light on the optical receiver. Methods of using and manufacturing the system are also disclosed.

Abstract: Provided is a mask changing unit for a laser bonding apparatus, and more particularly, a mask changing unit for a laser bonding apparatus, wherein the mask changing unit supplies or changes a mask to or in the laser bonding apparatus for bonding a semiconductor chip to a substrate by using a laser beam. The mask changing unit for a laser bonding apparatus, a plurality of masks that are used in performing laser bonding of a semiconductor chip to a substrate while the semiconductor chip is being pressed may be easily supplied to the laser bonding apparatus or changed in the laser bonding apparatus.

Abstract: A semiconductor laser diode is specified, the semiconductor laser diode includes a semiconductor layer sequence having an active layer which has a main extension plane and which, in operation, is adapted to generate light in an active region and to emit light via a light-outcoupling surface, the active region extending from a rear surface opposite the light-outcoupling surface to the light-outcoupling surface along a longitudinal direction in the main extension plane, the semiconductor layer sequence having a surface region on which a first cladding layer is applied in direct contact, the first cladding layer having a transparent material from a material system different from the semiconductor layer sequence, and the first cladding layer being structured and having a first structure.

Abstract: A corrected mesa structure for a VCSEL device is particularly configured to compensate for variations in the shape of the created oxide aperture that result from anisotropic oxidation. In particular, a corrected mesa shape is derived by determining the shape of an as-created aperture formed by oxidizing a circular mesa structure, and then ascertaining the compensation required to convert the as-created shape into a desired (“target”) shaped aperture opening. The compensation value is then used to modify the shape of the mesa itself such that a following anisotropic oxidation yields a target-shaped oxide aperture.

Abstract: A laser arrangement includes a laser array, and an optical arrangement. The laser array includes lasers in a first pattern emitting a same laser emission profile around a first optical axis with a divergence angle ?/2. The optical arrangement has a diffusor with an array of optical elements in a second pattern, with a second optical axis, and with an illumination pattern along a first illumination axis in a field-of-view if laser light is received within a defined range smaller than or equal to a range of angles between ?/+? with respect to the second optical axis. A row of lasers parallel to the first illumination axis has a pitch p. A row of m optical elements is parallel to the first axis. Each optical element has a diameter L, and contacts its neighbor. The n lasers and the m optical elements satisfy n*p=m*L with a deviation smaller than +/?5%.

Abstract: A near-eye display apparatus is configured to be disposed in front of at least one eye of a user and includes an illumination system, a display device, and a micro-lens array. The illumination system is configured to provide an illumination beam including sub-illumination beams. The display device is located on a transmission path of the illumination beam. The sub-illumination beams form corresponding sub-illumination regions on the display device, and the display device is configured to convert the sub-illumination beams irradiating the display device and corresponding to the sub-illumination regions into sub-image beams. An exit angle of each sub-image beam emitted from the display device is less than or equal to 20 degrees. The near-eye display apparatus provided herein is capable of eliminating stray light and characterized by good quality.

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: A light projection system includes a light source configured to emit image light and an optical assembly configured to provide positive optical power to the image light and optically correct the image light. The optical assembly comprises a plurality of optical elements configured to correct differential distortion related to the image light across a field of view (FOV) within a threshold amount. The differential distortion is corrected based in part on asymmetry of the plurality of optical elements relative to an optical axis shared by the plurality of optical elements.

Abstract: A laser diode includes a semiconductor structure having an n-type layer, an active region, and a p-type layer. One of the n-type and p-type layers includes a lasing aperture thereon having an optical axis oriented perpendicular to a surface of the active region between the n-type and p-type layers. First and second contacts are electrically connected to the n-type and p-type layers, respectively. The first and/or second contacts are smaller than the lasing aperture in at least one dimension. Related arrays and methods of fabrication are also discussed.

Abstract: An optoelectronic device includes a semiconductor substrate and an array of optoelectronic cells, formed on the semiconductor substrate. The cells include first epitaxial layers defining a lower distributed Bragg-reflector (DBR) stack; second epitaxial layers formed over the lower DBR stack, defining a quantum well structure; third epitaxial layers, formed over the quantum well structure, defining an upper DBR stack; and electrodes formed over the upper DBR stack, which are configurable to inject an excitation current into the quantum well structure of each optoelectronic cell. A first set of the optoelectronic cells are configured to emit laser radiation in response to the excitation current. In a second set of the optoelectronic cells, interleaved with the first set, at least one element of the optoelectronic cells, selected from among the epitaxial layers and the electrodes, is configured so that the optoelectronic cells in the second set do not emit the laser radiation.

Abstract: A mobile device includes an image sensor separated from a processing component by an open space. The image sensor includes one or more light source modules and the processing component includes one or more light sensors aligned with the one or more light source modules. Image data from the image sensor may be transmitted to the processing component via light signals exchanged between the one or more light source modules and the one or more light sensors. In some embodiments, light signals transmitted between one or more light source modules of an image sensor and one or more light sensors of the processing component are used to determine positional and angular data about the image sensor.

Abstract: An optical apparatus is provided for an optical transceiver. The optical apparatus includes an interposer, a glass lens chip bonded to the interposer, and a plurality of bottom-emitting vertical-cavity surface-emitting lasers (VCSELs) flip chipped to the interposer. Each of the bottom-emitting VCSELs is fabricated on a respective substrate, at least one bottom-emitting VCSEL is capable of emitting an optical signal having a wavelength of about 850 nm, and at least a portion of the respective substrate on which the at least one bottom-emitting VCSEL is fabricated is removed to permit the at least one bottom-emitting VCSEL to emit the optical signal having the wavelength of about 850 nm to the glass lens chip.

Abstract: A method of manufacturing a light emitting device includes: providing a light emitting device in which a first and second semiconductor laser elements are connected in series; performing a first measurement that includes supplying current to the first semiconductor laser element to measure at least one property of the first semiconductor laser element, and supplying current to the second semiconductor laser element to measure at least one property of the second semiconductor laser element; supplying current to the first and second semiconductor laser elements for a length of time; performing a second measurement that includes supplying current to the first semiconductor laser element to measure the at least one property of the first semiconductor laser element, and supplying current to the second semiconductor laser element to measure the at least one property of the second semiconductor laser element, and evaluating the first and second semiconductor laser elements.

Abstract: Techniques of minimizing or eliminating stresses in silicon photonic integrated circuits (Si-PICs) and in semiconductor packages having one or more Si-PICs (Si-PIC packages) are described. An Si-PIC or an Si-PIC package includes a stress minimization solution that assists with filtering out stresses by selectively isolating photonic and/or electronic devices, by isolating components or devices in an Si-PIC or an Si-PIC package that are sources of stress, or by isolating an Si-PIC in an Si-PIC package. The stress minimization solution may include strategically placed cavities and a stage that assist with minimizing or preventing transfer of stress to one or more photonic and/or electronic devices in an Si-PIC or an Si-PIC package.

Abstract: An optoelectronic device includes a semiconductor substrate and an array of optoelectronic cells, formed on the semiconductor substrate. The cells include first epitaxial layers defining a lower distributed Bragg-reflector (DBR) stack; second epitaxial layers formed over the lower DBR stack, defining a quantum well structure; third epitaxial layers, formed over the quantum well structure, defining an upper DBR stack; and electrodes formed over the upper DBR stack, which are configurable to inject an excitation current into the quantum well structure of each optoelectronic cell. A first set of the optoelectronic cells are configured to emit laser radiation in response to the excitation current. In a second set of the optoelectronic cells, interleaved with the first set, at least one element of the optoelectronic cells, selected from among the epitaxial layers and the electrodes, is configured so that the optoelectronic cells in the second set do not emit the laser radiation.

Abstract: A spectral imager, including: a photodetector including a plurality of photosensitive sites exposed on a photosensitive surface; a collimating lens including an intermediate focal plane; an array of interferometers including two main waves, each including a cavity defined by two faces; an array of microlenses arranged in a plane parallel to the photosensitive surface, each microlens paired with an interferometer to form an optical pair, including an image focal plane coinciding with the photosensitive surface and facing a section of the photosensitive surface.

Abstract: This disclosure describes an optoelectronic to provide ultra-precise and stable packaging for an optoelectronic device such as a light emitter or light detector. The module includes spacers to establish precise separation distances between various parts of the module. One of the spacers serves as a support or mount for an optical element that comprises a mask.

Abstract: A vertical cavity surface emitting laser (VCSEL) array may comprise a doped substrate layer. The VCSEL array may comprise a plurality of VCSELs on the doped substrate layer. The VCSEL array may comprise a buffer structure between the doped substrate layer and the plurality of VCSELs. The buffer structure, or a combination of the buffer structure and a layer of the plurality of VCSELs, may provide electrical isolation from the plurality of VCSELs to the doped substrate layer. The VCSEL array may comprise an isolation structure between adjacent VCSELs of the plurality of VCSELs. The isolation structure may provide electrical isolation between a first VCSEL, of the adjacent VCSELs, and a second VCSEL of the adjacent VCSELs. The first VCSEL and the second VCSEL may be different VCSELs.

Abstract: A proximity sensing module with dual transmitters includes a circuit board, a package housing, a transmitter unit and a sensing assembly. The transmitter unit includes a first transmitter and a second transmitter. The first transmitter and the second transmitter are disposed on the circuit board. The sensing assembly includes a sensor disposed on the circuit board. The transmitter unit is shielded from the sensing assembly through the package housing. One of the first transmitter and the second transmitter is nearer to the sensing assembly than the other one is.

Abstract: A highly efficient laser ignition device is provided. The highly efficient laser ignition device fundamentally includes: a pumping light source adopting a multi-chip single emitter-packaged optical fiber output laser diode; a laser medium to which ytterbium is added; and a saturated absorber as a passive Q-switch medium, wherein a pulse of 100-999 ps as the passive Q-switch laser output can be obtained. According to the disclosed, the problems of high cost/low efficiency/low reliance/non-uniformity, which are disadvantages for replacing an ignition device using an electric spark with a laser ignition device, can be solved.

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: Disclosed herein are light emitting diodes (LEDs) having a high efficiency. A light emitting diode including an active light emitting layer within a semiconductor layer is provided. The semiconductor layer has a mesa shape. The light emitting diode also includes a substrate having a first surface on which the semiconductor layer is positioned and an outcoupling surface opposite to the first surface. Light generated by the active light emitting layer is incident on the outcoupling surface and propagates toward an optical element downstream of the outcoupling surface. The light emitting diode also includes a first anti-reflection coating adjacent to the outcoupling surface; an index-matched material between the outcoupling surface and the optical element, wherein an index of refraction of the index-matched material is greater than or equal to an index of refraction of the optical element; and/or secondary optics adjacent to the outcoupling surface.

Abstract: A semiconductor laser device of an embodiment comprises: a first electrode having an opening for passage of laser light and arranged on a main surface of a substrate; and a second electrode arranged on a back surface of the substrate. A stacked structural body including an active layer and a photonic crystal layer is arranged between the substrate and the first electrode, and a current confinement layer having an opening for passage of a current is arranged between the stacked structural body and the first electrode. A maximum width of the opening of the current confinement layer is smaller than a maximum width of the opening of the first electrode, and a whole region defined by the opening of the current confinement layer fits within a region defined by the opening of the first electrode as viewed from the first electrode side toward the second electrode side.

Abstract: Photonic devices such as semiconductor lasers and photodetectors of various operating wavelengths are grown monolithically on a Silicon substrate, and formed of nanowire structures with quantum structures as active regions. A reduction of strain during fabrication results from the use of these nanowire structures, thereby allowing devices to operate for extended periods of time at elevated temperatures. Monolithic photonic devices and monolithic photonic integrated circuits formed on Silicon substrates are thus provided.

Abstract: An example device in accordance with an aspect of the present disclosure includes a slab to transmit light, and a plurality of lenses and filters disposed on first and second surfaces of the slab. The lenses include an anti-reflective coating on at least one of the plurality of lenses at an end of the slab to couple light through the anti-reflective coating, and a reflective coating disposed on remaining ones of the plurality of lenses to cause the lenses to reflect light. The filters are offset from the lenses to form an optical zig-zag.

Abstract: Optical systems and methods for collecting distance information are disclosed. An example optical system includes a bulk receiving optic, a plurality of illumination sources, a pixel array comprising at least a first column of pixels and a second column of pixels, each pixel in the first column of pixels being offset from an adjacent pixel in the first column of pixels by a first pixel pitch, the second column of pixels being horizontally offset from the first column of pixels by the first pixel pitch, the second column of pixels being vertically offset from the first column of pixels by a first vertical pitch; and a set of input channels interposed between the bulk receiving optic and the pixel array.

Abstract: An organic light emitting diode (OLED) having an organic electroluminescent layer formed between a first electrode and a second electrode. One of the first and second electrodes is a transparent electrode having a surface through which light is emitted from the OLED to the outside. The transparent electrode has a plasmonic photonic crystal structure fabricated having an artificial lattice with a pitch in density variation intermediate in size between a metallic crystal and a photonic crystal formed in the same material as the transparent electrode, thereby operable to suppress propagation of the surface plasmon polaritons at the surface.

Abstract: A vertical cavity surface emitting laser (VCSEL) array may comprise a doped substrate layer. The VCSEL array may comprise a plurality of VCSELs on the doped substrate layer. The VCSEL array may comprise a buffer structure between the doped substrate layer and the plurality of VCSELs. The buffer structure, or a combination of the buffer structure and a layer of the plurality of VCSELs, may provide electrical isolation from the plurality of VCSELs to the doped substrate layer. The VCSEL array may comprise an isolation structure between adjacent VCSELs of the plurality of VCSELs. The isolation structure may provide electrical isolation between a first VCSEL, of the adjacent VCSELs, and a second VCSEL of the adjacent VCSELs. The first VCSEL and the second VCSEL may be different VCSELs.

Abstract: The present application relates to vertically integrated assemblies including a MEMS-based optomechanical architecture. In some embodiments, the assembly includes a MEMS/optoelectronic module, an emitter module, and a detector module, where these modules are vertically integrated. Methods of fabricating such assemblies are also described herein.

Abstract: A structure includes an optoelectronic device having a Group IV substrate (e.g., Si); a buffer layer (e.g. SiGe) disposed on the substrate and a first distributed Bragg reflector (DBR) disposed on the buffer layer. The first DBR contains alternating layers of doped Group IV materials (e.g., alternating layers of SiyGe(1?y), where 0.8<y<1, and SizGe(1?z), where 0.2<z<0.4) that are substantially transparent to a wavelength of interest. The structure further includes a strained layer of a Group III-V material over the first DBR and a second DBR over the strained layer. The second DBR contains alternating layers of electrically conductive oxides (e.g., ITO/AZO) that are substantially transparent to the wavelength of interest. Embodiments of VCSELs and photodetectors can be derived from the structure. The strained layer of Group III-V material can be, for example, a thin layer of In0.53Ga0.47As having a thickness in a range of about 2 nm to about 5 nm.

Abstract: A surface-emitting semiconductor laser system contains at least one MQW unit of at least three constituent QWs, axially separated from one another substantially non-equidistantly. The MQW unit is located within the axial extent covered, in operation of the laser, by a half-cycle of the standing wave of the field at a wavelength within the gain spectrum of the gain medium; immediately neighboring nodes of the standing wave are on opposite sides of the MQW unit. So-configured MQW unit can be repeated multiple times and/or complemented with individual QWs disposed outside of the half-cycle of the standing wave with which such MQW unit is associated. The semiconductor laser further includes a pump source configured to input energy in the semiconductor gain medium and a mode-locking element to initiate mode-locking.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2, and to generate output light of a difference frequency ? by difference frequency generation. An external diffraction grating is provided constituting an external cavity for generating the first pump light and configured to be capable of changing the frequency ?1, outside an element structure portion including the active layer. Grooves respectively formed in a direction intersecting with a resonating direction are provided on a second surface of the substrate.

Abstract: Certain examples described herein relate to a surface-emitting semiconductor-laser which includes an oxide window, a light emitting cavity, and at least one phase matching window. The oxide window, the light emitting cavity, and the at least one phase matching layer are arranged so that a predetermined phase relationship is satisfied. The phase relationship facilitates high performance and stable multimode operations of the surface-emitting semiconductor laser designed to emit between 850-1060 nm wavelength for applications such as long distance optical communications in high performance computing and data servers.

Abstract: A photoelectric conversion connector comprising a support, a photoelectric conversion element that is provided on said support and that can be connected to an optical fiber through an optical signal, a first resin member that is formed at the upper part of the photoelectric conversion element, and a second resin member that is formed at the upper part of the first resin member. An optical signal transmitted between the photoelectric conversion element and the optical fiber goes through both the first resin member and the second resin member.

Abstract: The disclosure is directed at a method and apparatus for producing a detector element. The detector element includes first and second electrodes located on opposites sides of a semiconductor layer. The first and second electrodes are staggered with respect to each other in a plane perpendicular to the semiconductor layer.

Abstract: An optoelectronic device comprises microwires or nanowires, each of which comprises an alternation of passivated portions and of active portions, the active portions being surrounded with an active layer, where the active layers do not extend on the passivated portions.

Abstract: An imaging system color image acquisition including: an image sensor; a tunable spectral filter arranged in an optical path of light propagation towards the image sensor; and a controller connected to the image sensor and to the tunable spectral filter. The controller is configured and operable for generating a colored image by sequentially operating the tunable spectral filter for sequentially filtering light passing towards the image sensor with three or more different spectral filtering curves during three or more corresponding integration time durations. The tunable spectral filter is configured, as an etalon and includes a pair of reflective surfaces. At least one of the reflective surfaces includes a layer of high refractive index of at least n=2.3 or even higher than 3, or a layer of low refractive index, smaller than n=1.

Abstract: The present invention relates to a laser device being formed of at least one VCSEL (15) with intracavity contacts. The VCSEL comprises a layer structure (18) with an active region (6) between a first DBR (4) and a second DBR (10), a first current-injection layer (5) of a first conductivity type between the first DBR (4) and the active region (6), and a second current-injection layer (8) of a second conductivity type between the second DBR (10) and the active region (6). The first and second current-injection layers (5, 8) are in contact with a first and a second metallic contact (11, 12), respectively. The first and/or second DBR (4, 10) are formed of alternating Aluminum oxide and Al(x)Ga(1?x)As containing layers. The proposed design of this VCSEL allows an increased efficiency and lower production costs of such a laser since the top and bottom DBRs may be formed of a considerable reduced thickness.

Abstract: Embodiments of the present invention generally relate to a method for forming a HAMR device having a photonic integrated circuit that includes an optical detector, an optical emitter, and an optical element distinct from the optical detector and the optical emitter, where the elements of the photonic integrated circuit are aligned with a near field transducer. The method includes forming one or more layers on a substrate, bonding the layers to a partially fabricated recording head, removing the substrate using epitaxial lift-off, and forming the optical elements on the partially fabricated recording head.

Abstract: An optical communication module includes a plurality of semiconductor lasers that emit optical signals with different wavelengths, a multiplexing optical system including a plurality of optical filters used for multiplexing the optical signals, each of which has been emitted from a corresponding one of the plurality of semiconductor lasers, and a substrate on which the optical filters are provided, and a plurality of lenses, each of the lenses being joined to a corresponding one of the plurality of optical filters to condense or collimate an optical signal emitted from a corresponding one of the semiconductor lasers and thereby enable the light signal to enter the optical filter. The plurality of lenses are independent from one another and have a different linear expansion ratio from that of the substrate. Furthermore, the plurality of lenses are not in contact with a second mount on which the substrate is mounted.

Abstract: An exemplary embodiment of the present disclosure illustrates a gesture sensing module disposed on a substrate. The gesture sensing module includes at least one light emitting unit, at least one light sensor, and a control circuit. The light emitting unit provides a light to illuminate a sensing area, wherein a central optical axis of the light forms an angle with a normal vector of the substrate, and the angle is not equal to 0. The light sensor senses a reflection light which a target in the sensing area reflects the light, and generate a sensing signal according to the reflection light. The control circuit coupled to the light sensor and the light emitting unit determines a traveling direction of the target according to the sensing signal.

Abstract: An image sensor including: a plurality of pixels, wherein a first pixel of the pixels includes: a first photoelectric conversion element; and a first microlens overlapping the first photoelectric conversion element, wherein the first microlens reflects wavelengths of a first region of visible light and allows wavelengths of second and third regions of visible light to pass through to the first photoelectric conversion element.

Abstract: A transistor device is provided that includes a gate electrode disposed between source and drain electrodes and overlying a quantum dot structure realized by a modulation doped quantum well structure. A potential barrier surrounds the quantum dot structure. The transistor device can be configured for operation as a single electron transistor by means for biasing the gate and source electrodes to allow for tunneling of a single electron from the source electrode through the potential barrier surrounding the quantum dot structure and into the quantum dot structure, and means for biasing the gate and drain electrodes to allow for selective tunneling of a single electron from the quantum dot structure through the potential barrier surrounding the quantum dot structure to the drain electrode, wherein the selective tunneling of the single electron is based upon spin state of the single electron.

Abstract: Heat management systems for vertical cavity surface emitting laser (VCSEL) chips are provided. Embodiments of the invention provide substrates having a vertical cavity surface emitting laser chip disposed on the substrate surface and electrically interconnected with the substrate, a thermal frame disposed on the substrate surface and proximate to at least three sides of the vertical cavity surface emitting laser chip, and a thermal interface material disposed between the at least three sides of the vertical cavity surface emitting laser chip and the thermal frame. The substrate can also include a transceiver chip that is operably coupled to a further integrated circuit chip and that is capable of driving the VCSEL chip.

Abstract: The present invention provides a surface emitting laser that provides a sufficient optical output and is suitable as a light source intended for electrophotographic apparatuses, and a surface-emitting-laser array and an image forming apparatus each including the surface emitting laser. The surface emitting laser includes a first stepped structure on a front surface of a front mirror. In the first stepped structure, a difference L between an optical path length in a first area and an optical path length in a second area satisfies the following expression: (¼+N)?<|L|<(¾+N)? where N is an integer.

Abstract: A semiconductor laser device that enables flip-chip assembly by having an embedding section around a mesa section, and that has an improved emission lifetime, as well as a photoelectric converter and an optical information processing unit each having such a semiconductor laser device. The semiconductor laser device includes: a mesa section including an active layer, and having a first electrode on a top surface; an embedding section covering the mesa section, and having a first connection aperture that reaches the first electrode; and a first wiring provided on the embedding section overlaying the first connection aperture, the first wiring being electrically connected to the first electrode through the first connection aperture.

Abstract: Lighting apparatus and method for detecting reflected light from local objects are disclosed. A controller within a lighting apparatus is used to activate and deactivate one or more LEDs within a duty cycle. The controller uses a light detection apparatus that is optically isolated from the LEDs to sample light levels during a time in which the LEDs are deactivated and during a time in which the LEDs are activated. The light level when the LEDs are deactivated is an indication of the ambient light levels within the surrounding area of the lighting apparatus. The light level when the LEDs are activated is an indication of the ambient light levels combined with any light generated by the LEDs that is reflected onto the light detection apparatus. By comparing these light levels, the controller can determine the level of light attributable to reflected light from the LEDs.

Abstract: A surface-emitting laser device includes a transparent dielectric layer provided in an emitting region and configured to cause a reflectance at a peripheral part to be different from a reflectance at a central part in the emitting region. In the surface-emitting laser device, the thickness of a contact layer is different between a region having a relatively high reflectance and a region having a relatively low reflectance in the emitting region. The contact layer is provided on the high refractive index layer of an upper multilayer film reflecting mirror, and the total optical thickness of the high refractive index layer and the contact layer in the region having the relatively low reflectance is deviated from an odd number multiple of a one quarter oscillation wavelength of laser light emitted from the emitting region.

Abstract: A two-dimensional photonic crystal laser according to the present invention includes a two-dimensional photonic crystal layer 15 having a base body made of Al?Ga1-?As (0<?<1) or (Al?Ga1-?)?In1-?P (0<=?<1, 0<?<1) with modified refractive index areas (air holes) 151 periodically arranged therein and an epitaxial growth layer 16 created on the two-dimensional photonic crystal layer 15 by an epitaxial method. Since Al?Ga1-?As and (Al?Ga1-?)?In1-?P are solid even at high temperatures, the air holes 151 will not be deformed in the process of creating the epitaxial growth layer 16, so that the performance of the two-dimensional photonic crystal layer 15 as a resonator can be maintained at high levels.