Abstract: A two-dimensional photonic-crystal surface-emitting laser includes an active layer, a two-dimensional photonic crystal, and electrodes. The two-dimensional photonic crystal contains a plate-shaped base material arranged on one side of the active layer and different refractive index portions arranged at lattice points of a predetermined lattice in the base material and having a refractive index different from that of the base material, a band edge frequency for each position in an electric current supply region, which is at least a part of the two-dimensional photonic crystal, is monotonically increased in one direction parallel to the base material. Such a two-dimensional photonic crystal occurs when the different refractive index portion has a refractive index smaller than that of the base material, a filling factor, which is a ratio of a volume occupied by the different refractive index portion in a unit lattice constituting the lattice, is monotonically increased in the one direction.

Abstract: A micro-LED chip includes multiple micro-LEDs. At least one micro-LED of the multiple micro-LEDs includes: a first type conductive layer; a second type conductive layer stacked on the first type conductive layer; and a light emitting layer formed between the first type conductive layer and the second type conductive layer. The light emitting layer is continuously formed on the whole micro-LED chip, the multiple micro-LEDs sharing the light emitting layer. A profile of the first type conductive layer perpendicularly projected on a bottom surface of the second type conductive layer is surrounded by an edge of the second type conductive layer.

Abstract: An external resonator-type semiconductor laser device 1A includes an external resonator formed of one or a plurality of laser diode light sources and a VBG; an optical fiber which outputs output light La from the laser diode light source toward the VBG, and into which return light Lb from the VBG is input; and a displacement unit that displaces a disposition position of the VBG with respect to an input and output end surface of the optical fiber.

Abstract: An apparatus that relies on patterned metasurfaces to reduce speckle when illuminating an object with coherent light. The metasurfaces serve to increase one or more of angle diversity and wavelength diversity resulting from illumination by a coherent source.

Abstract: An apparatus comprises an array of vertical-cavity surface-emitting lasers. Each of the vertical-cavity surface-emitting lasers is configured to be a source of light. The apparatus also comprises an optical arrangement configured to receive light from a plurality of the vertical-cavity surface-emitting lasers and to output a plurality of light beams.

Abstract: In various embodiments, pointing errors in a non-wavelength-beam-combining dimension of a laser system are at least partially alleviated via staircased collimation lenses.

Abstract: A vertical-cavity surface-emitting laser (VCSEL) including a substrate including a plurality of emitters forming an array region, a lower mirror, an upper mirror, an active layer interposed between the lower mirror and the upper mirror, an aperture forming layer interposed between the upper mirror and the active layer and including an oxidation region and a window region, a connector disposed on the upper mirror, a plurality of oxidation holes passing through the upper mirror and the aperture forming layer, an upper insulation layer covering the plurality of oxidation holes, and a pad electrically connected to the connector, in which at least a portion of the connector is disposed in the plurality of oxidation holes, and the plurality of emitters is disposed in substantially a honeycomb shape on the substrate.

Abstract: An optical semiconductor device includes a semiconductor substrate; a plurality of mesa stripes, which are arranged side by side on the semiconductor substrate, and each of which includes an active layer and a diffraction grating, the diffraction grating extending up to a back end surface of each of the plurality of mesa stripes; a plurality of electrodes, each of which is electrically connected to an upper surface of a corresponding one of the plurality of mesa stripes, having a pad portion for wire bonding; a plurality of waveguides, each of which is optically connected to the active layer of a corresponding one of the plurality of mesa stripes; and a reflective film provided at back end surfaces of the plurality of mesa stripes, and wherein at least two mesa stripes, of the plurality of mesa stripes, are configured to be driven at the same time.

Abstract: The diode laser comprises a laser bar having a semiconductor body and an active layer, wherein the laser bar has a plurality of individual emitters. At least some individual emitters are respectively assigned a section of the semiconductor body and a current regulating element connected in series therewith, such that, during operation of the individual emitters as intended, an electrical operating current I0 fed to the individual emitter in each case flows completely through the assigned section of the semiconductor body and in the process a voltage drop UH occurs at the section and at least part of said operating current I0 flows through the assigned current regulating element and experiences an electrical resistance RS in the process. In the case of the individual emitters, the current regulating element assigned in each case is configured such that the resistance Rg at an operating temperature T0 has a positive temperature coefficient dRS/dT|T0.

Abstract: A laser device comprises a hermetic housing that has an interior and is made at least in part of printed circuit board material, a laser element located in the interior, and at least one inorganic layer which hermetically shields the interior from the printed circuit board material.

Abstract: A header for a semiconductor package includes: an eyelet having an upper surface and a lower surface; a first metal block molded integrally with the eyelet, protruding at the upper surface, and having a substantially U shape; a first lead sealed in a first through hole penetrating the eyelet; a first substrate having a front surface formed with a first signal pattern electrically connected to the first lead and having a back surface fixed to a first end surface of the first metal block; a second lead sealed in a second through hole penetrating the eyelet; and a second substrate having a front surface formed with a second signal pattern electrically connected to the second lead and having a back surface fixed to a second end surface of the first metal block.

Abstract: In one embodiment, the semiconductor laser (1) comprises a semiconductor layer sequence (2) based on the material system AlInGaN with at least one active zone (22) for generating laser radiation. A heat sink (3) is thermally connected to the semiconductor layer sequence (2) and has a thermal resistance towards the semiconductor layer sequence (2). The semiconductor layer sequence (2) is divided into a plurality of emitter strips (4) and each emitter strip (4) has a width (b) of at most 0.3 mm in the direction perpendicular to a beam direction (R). The emitter strips (4) are arranged with a filling factor (FF) of less than or equal to 0.4. The filling factor (FF) is set such that laser radiation having a maximum optical output power (P) can be generated during operation.

Abstract: A method of fabricating a radiation emitter including fabricating a layer stack that includes a first reflector, at least one intermediate layer, an active region and a second reflector; locally oxidizing the intermediate layer and thereby forming at least one unoxidized aperture; and locally removing the layer stack, and thereby forming a mesa that includes the first reflector, the unoxidized aperture, the active region, and the second reflector. Before or after locally removing the layer stack and forming the mesa: forming at least a first unoxidized aperture and at least a second unoxidized aperture inside the intermediate layer; etching a trench inside the layer stack, the trench defining a first portion and a second portion of the mesa, wherein the trench severs the intermediate layer(s) so that the first aperture is located in the first portion and the second aperture is located in the second portion of the mesa.

Abstract: Provided is a preparation method of a detector material. The present disclosure epitaxially grows a buffer layer on a surface of a gallium arsenide substrate, deposits a silicon dioxide layer on the buffer layer, and etches the silicon dioxide layer on the buffer layer according to a strip pattern by photolithography and etching to form strip growth regions with continuous changes in width. Finally, a molecular beam epitaxy (MBE) technology is used to epitaxially grow the detector material in the strip growth regions under set epitaxy growth conditions. Because of the same mobility of atoms arriving at the surface of the substrate, numbers of atoms migrating to the strip growth regions are different due to different widths of the strip growth regions, such that compositions of the material change with the widths of the strip growth regions or a layer thickness changes with the widths of the strip growth regions.

Abstract: Arrays of optical emitters, modulators, receivers and/or optoelectronic devices used in communication are printed with redundant elements to provide multiple solutions to select from at screening time to improve overall yield. Multiple optoelectronic devices are printed on common chiplets, tightly packed, or printed in sub-arrays.

Abstract: A broadband tuning system includes a first chip and a second chip. The first chip includes a first light amplification region, a first forward grating region and a first backward grating region that are sequentially arranged in a first direction. The first light amplification region is configured to amplify a first light source and to turn on or turn off the first light source, and the first forward grating region and the first backward grating region are configured to tune the first light source. The second chip includes a second light amplification region, a second forward grating region and a second backward grating region that are sequentially arranged in a second direction. The second light amplification region is configured to amplify a second light source and to turn on or turn off the second light source, and the second forward grating region and the second backward grating region are configured to tune the second light source.

Abstract: A light emitting device includes: a substrate including a main surface; a first projection positioned on the main surface, the first projection including an upper surface and first and second lateral surfaces, wherein the first lateral surface of the first projection comprises a first reflective part, and the second lateral surface of the first projection comprises a second reflective part; a first laser element positioned on the main surface at a first reflective part side with respect to the first projection, the first laser element being configured to irradiate first laser light to the first reflective part; a second laser element positioned on the main surface at a second reflective part side with respect to the first projection, the second laser element being configured to irradiate second laser light to the second reflective part; and a first optical member bonded to the upper surface of the first projection.

Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: A laser chip including a plurality of stripes is disclosed, where a laser stripe can be grown with an initial optical gain profile, and its optical gain profile can be shifted by using an intermixing process. In this manner, multiple laser stripes can be formed on the same laser chip from the same epitaxial wafer, where at least one laser stripe can have an optical gain profile shifted relative to another laser stripe. For example, each laser stripe can have a shifted optical gain profile relative to its neighboring laser stripe, thereby each laser stripe can emit light with a different range of wavelengths. The laser chip can emit light across a wide range of wavelengths. Examples of the disclosure further includes different regions of a given laser stripe having different intermixing amounts.

Abstract: In a WBC system of the present disclosure, an LD bar array constituted by a plurality of LD bars is configured such that a main axis direction of an off-angle of at least one LD bar is reversed with respect to a main axis direction of an off-angle of the other LD bar. By doing so, even in the LD bar in which a wavelength distribution in a wafer exists, a difference between a designed lock wavelength and a gain peak wavelength can be kept within a range where an LD oscillation due to an external resonance is possible for all emitters in the LD bar, thereby an output in the WBC system can be maximized.

Abstract: A laser integrated photonic platform to allow for independent fabrication and development of laser systems in silicon photonics. The photonic platform includes a silicon substrate with an upper surface, one or more through silicon vias (TSVs) defined through the silicon substrate, and passive alignment features in the substrate. The photonic platform includes a silicon substrate wafer with through silicon vias (TSVs) defined through the silicon substrate, and passive alignment features in the substrate for mating the photonic platform to a photonics integrated circuit. The photonic platform also includes a III-V semiconductor material structure wafer, where the III-V wafer is bonded to the upper surface of the silicon substrate and includes at least one active layer forming a light source for the photonic platform.

Abstract: A laser module, includes: an optical fiber; n laser diodes LDi (i=1, 2, . . . , n) arranged in an order corresponding to a descending order of optical path lengths LOi of optical paths respectively extending from the laser diodes LDi to the optical fiber; and n collimating lenses SLi respectively disposed in the optical paths to be distant from the respective laser diodes LDi and from the optical fiber. When a distance from each of the laser diodes LDi to a corresponding one of the collimating lenses SLi is defined as a collimation length LCi, at least one of a collimation length LC1 and a collimation length LCn differs from a certain distance SL that is set with respect to each of the collimating lenses SLi.

Abstract: A wavelength tunable light source includes: a common wavelength filter that has periodic transmission peak wavelengths or reflection peak wavelengths and is commonly used for a plurality of channels; a wavelength tunable filter that is coupled to the common wavelength filter and has a one-input and multiple-output configuration which has a plurality of output ports, and that has a plurality of transmission peak wavelengths corresponding to the plurality of channels at the plurality of output ports; and a plurality of gain media optically coupled to the plurality of output ports of the wavelength tunable filter, wherein a plurality of laser cavities that perform laser oscillation at a plurality of different wavelengths are formed between the common wavelength filter and the plurality of gain media.

Abstract: A storage system and method for retention-based zone determination are provided. In one embodiment, a storage system is presented comprising a memory comprising a plurality of blocks and a controller. The controller is configured to receive, from a host, a zone-create command comprising a health requirement; and in response to receiving the zone-create command, create a zone of memory from blocks of the memory that satisfy the health requirement. Other embodiments are provided.

Abstract: In a WBC system of the present disclosure, an LD bar array constituted by a plurality of LD bars is configured such that a main axis direction of an off-angle of at least one LD bar is reversed with respect to a main axis direction of an off-angle of the other LD bar. By doing so, even in the LD bar in which a wavelength distribution in a wafer exists, a difference between a designed lock wavelength and a gain peak wavelength can be kept within a range where an LD oscillation due to an external resonance is possible for all emitters in the LD bar, thereby an output in the WBC system can be maximized.

Abstract: A light emitting element (semiconductor laser element) includes a multilayer structure in which a substrate, semiconductor layers to, an insulating layer, and a metal layer are stacked in order. The light emitting element includes a plurality of light emitting portions each of which emits a laser beam. The plurality of light emitting portions each include a ridge (ridge waveguide). The distance from a specific position in an active region in at least one of the light emitting portions to an inner surface of the metal layer is different from that in another of the light emitting portions.

Abstract: A vertical cavity surface emitting laser (VCSEL) array may include a plurality of VCSELs. A size of an emission area of a first VCSEL, of the plurality of VCSELs, may be different from a size of an emission area of a second VCSEL of the plurality of VCSELs. The first VCSEL may be located closer to a center of the VCSEL array than the second VCSEL. A difference between the size of the emission area of the first VCSEL and the size of the emission area of the second VCSEL may be associated with reducing a difference in operating temperature between the first VCSEL and the second VCSEL, or reducing a difference in optical power output between the first VCSEL and the second VCSEL.

Abstract: A LIDAR sensor, including: a transceiver-array, which includes a plurality of optical-transceivers, the transceiver-array being a switched-array photonic integrated-circuit, each of the optical-transceivers being set up to in each instance take in a first scanning-spot in a first field-of-view of the LIDAR sensor; a microlens-array which has a plurality of microlenses, the microlens-array being disposed in an optical path of the LIDAR sensor in front of the transceiver array, one each of the microlenses in the optical-path being situated in front of one each of the optical-transceivers; a lens that is disposed in the optical-path in front of the microlens-array; and an optical-scanning-unit which is equipped to alter an optical-beam-path, that starts from one of the optical-transceivers, so that in each instance, a second scanning-spot in the first field-of-view of the LIDAR sensor is sensed by the optical-transceivers, the first scanning-spots lying between the second scanning-spots.

Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: A light emitting device includes a light emitting structure, first and second electrodes, and a shielding layer. The light emitting structure includes a first-type semiconductor layer, an active layer, and a second-type semiconductor layer that are stacked along a stacking direction in such order. The first electrode is electrically connected to the first-type semiconductor layer. The second electrode is electrically connected to the second-type semiconductor layer. The shielding layer is connected to aside of the light emitting structure and is adapted to absorb or reflect incident laser light.

Abstract: A light emitting device includes an edge emitting laser chip and a reflecting mirror. The edge emitting laser chip has light emitting ports arranged in parallel in a first direction. The light emitting ports emit light beams in a second direction. The reflecting mirror includes a reflecting surface used to reflect the light beams to a third direction. The first, second and third direction are perpendicular to each other. The light beams are emitted to the reflecting surface through the virtual incident plane and project first light spots on the reflecting surface. Each projected light spot has a first axis length in the first direction and a third axis length in the third direction. An interval between two immediately-adjacent light emitting ports is greater than the first axis length of one of the two projected light spots aligned with the two immediately-adjacent light emitting ports.

Abstract: An electronic power module, including at least one semiconductor component, which is arranged on a support, as well as a cooling element, which is in thermal contact with the semiconductor component, wherein the support includes a semiconductor material and, at the same time, serves as a cooling element.

Abstract: A photon source may have a substrate, a focus lens disposed above the substrate, and a plurality of optical sources disposed on the substrate. Each optical source may have a mirror disposed on the substrate configured to reflect a collimated beam emitted by an optical emitter disposed on the substrate. The plurality of mirrors may be arranged in a first ring-like configuration defining a first diameter. The plurality of optical emitters may be arranged in a second ring-like configuration defining a second diameter which is larger than the first diameter. In some aspects each optical source may include a second optical emitter emitting a second optical beam and an optical combiner configured to combine the first emitted optical beam and the second emitted optical beam to form the collimated beam. In another aspect, the photon source may be composed of a vertical array of multiple substrates.

Abstract: Provided is an optical interference light source device of a current-temperature controlled semiconductor laser, including a heat dissipation plate, a ring-shaped semiconductor refrigerating sheet, a semiconductor laser, a PCB board, a thermal sensor and a fixed plate. The first circular window copper area of the PCB is in contact with the second circular copper area through a via. A lower end of a housing of the semiconductor laser is connected to the first circular windowed copper area through a thermally conductive silicone grease. The ring-shaped semiconductor refrigerating sheet is connected to the first circular window copper area through a thermally conductive silicone grease connected to the heat dissipation plate. The thermal sensor is configured to detect a temperature of the first circular windowed copper area. The present disclosure has beneficial effects of simple structures, good thermal conductivities, high temperature control precisions, and stable output wavelengths of the laser.

Abstract: A soot particle sensor includes a laser module including a laser and a detector configured for the detection of temperature radiation. The soot particle sensor provides that the laser is configured to generate laser light, and the soot particle sensor includes an optical element situated in the beam path of the laser of the laser module, which is configured to bundle laser light originating from the laser module in a spot, and the detector is situated in the soot particle sensor so that it detects the radiation originating from the spot.

Abstract: A semiconductor light emitting device includes a mount section having an insulating property connected to a heat sink, a plurality of semiconductor laser elements disposed on the mount section, and a heat radiation block having an insulating property disposed on the plurality of semiconductor laser elements. A first wiring made of a metal is disposed on an upper surface of the mount section, and a second wiring made of a metal is disposed on a lower surface of the heat radiation block, a part of the second wiring being electrically connected to the first wiring. By electrically connecting the first wiring and the second wiring to each of the plurality of semiconductor laser elements, the plurality of semiconductor laser elements are connected in series, and have a same polarity with each other at a side that each of the plurality of semiconductor laser elements is connected to the first wiring.

Abstract: A VCSEL can include: an active region configured to emit light; a blocking region over or under the active region, the blocking region defining a plurality of channels therein; a plurality of conductive channel cores in the plurality of channels of the blocking region, wherein the plurality of conductive channel cores and blocking region form an isolation region; a top electrical contact; and a bottom electrical contact electrically coupled with the top electrical contact through the active region and plurality of conductive channel cores. At least one conductive channel core is a light emitter, and others can be spare light emitters, photodiodes, modulators, and combinations thereof. A waveguide can optically couple two or more of the conductive channel cores. In some aspects, the plurality of conductive channel cores are optically coupled to form a common light emitter that emits light (e.g., single mode) from the plurality of conductive channel cores.

Abstract: The present invention provides a multi-fiber laser output system that delivers at least three fiber outputs arranged in a circumferential pattern or otherwise at least four distinct laser outputs from a single processing cable. The present invention allows for controlling the at least three laser modules and delivering their respective outputs in a pre-determined sequence in a single processing cable, thereby providing multiple processing steps on a work piece that heretofore required separate optics for each beam. The at least three laser outputs are optimized for use in creating spot welds, seam welds or virtual wobble welds when used for seam welding.

Abstract: A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.

Abstract: Apparatus include a first laser diode situated to emit a beam from an exit facet along an optical axis, the beam as emitted having perpendicular fast and slow axes perpendicular to the optical axis, a first fast axis collimator (FAC) optically coupled to the beam as emitted from the exit facet and configured to direct the beam along a redirected beam axis having a non-zero angle with respect to the optical axis of the first laser diode, a second laser diode situated to emit a beam from an exit facet of the second laser diode along an optical axis parallel to the optical axis of the first laser diode and with a slow axis in a common plane with the slow axis of the first laser diode, and a second fast axis collimator (FAC) optically coupled to the beam as emitted from the exit facet of the second laser diode and configured to direct the beam along a redirected beam axis having a non-zero angle with respect to the optical axis of the second laser diode.

Abstract: Architecture and designs of wearable display devices are described. According to one aspect of the present invention, at least one optical conduit is embedded in or integrated with a temple of the wearable display device. The optical conduit is used to transport an optical image from one end to another end, where the optical image is generated in an image source (e.g., microdisplay) in accordance with image data. The microdisplay is powered and receives the image data and control signals via an active optical cable.

Abstract: Architecture and designs of wearable display devices are described. According to one aspect of the present invention, at least one optical conduit is embedded in or integrated with a temple of the wearable display device. The optical conduit is used to transport an optical image from one end to another end, where the optical image is generated in an image source (e.g., microdisplay) in accordance with image data. The microdisplay is powered and receives the image data and control signals via an active optical cable.

Abstract: A device for nullifying images captured by drones utilizing a high power light to overexpose said images. One or more cameras installed in the device capture images of the area surrounding the device. Computer vision and deep learning are utilized to identify drones in the captured images. If a drone is identified, the location thereof is estimated. A high power light installed in the device is directed at the estimated location of the drone to overexpose any images that are being taken of the area around the device by the drone.

Abstract: A semiconductor device has a semiconductor substrate and a first metallization stack arranged on the substrate. The substrate has and/or carries a plurality of electronic circuit elements. The first metallization stack has electrically insulating layers and at least one metallization layer. The semiconductor device further has a second metallization stack arranged on the first metallization stack and comprising further electrically insulating layers and an optical waveguide layer. The optical waveguide layer has at least one optical waveguide structure. Furthermore, one of the electrically insulating layers and one of the further electrically insulating layers are in direct contact with each other and form a pair of directly bonded layers.

Abstract: A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

Abstract: An illuminator according to an aspect of the invention includes a light source apparatus including a first light emitter that emits first light having a first color, a plurality of second light emitters that each emit second light having a second color, and a plurality of third light emitters that each emit third light having a third color, a rod integrator that combines the first light, the second light, and the third light with one another, a first lens that causes the first light, the second light, and the third light to be focused in the rod integrator, and a second lens that transmits only the first light out of the first light, the second light, and the third light. The plurality of second light emitters and the plurality of third light emitters are so disposed as to surround the first light emitter.

Abstract: A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

Abstract: A method and apparatus for enhancing the signal to noise ratio performance of a depth camera system are described. In one embodiment, the method includes exposing a portion of a pixel array of a rolling camera sensor, and activating a portion of a rolling projector to generate a portion of a projection pattern during the exposure of the portion of the pixel array. The method may also include capturing image data for the generated portion of the projection pattern with the exposed portion of the pixel array of the rolling camera sensor. Furthermore, the method may include performing depth reconstruction based, at least in part, on the captured image data.

Abstract: A multi-channel optical transceiver is disclosed. The optical transceiver has a multi-package structure. A laser array is disposed in one package. An application specific integrated circuit (ASIC) and photonic integrated circuit (PIC) are disposed in another package. An optical fiber array may couple the first package and second package together.

Abstract: The present technology includes: bonding a device formation side of a first substrate having a first device and a device formation side of a second substrate having a second device in opposition to each other; forming a protective film on at least an edge of the second substrate having the second device; and reducing a thickness of the first substrate.