Abstract: A semiconductor structure configured for use in a VCSEL or RCLED. The semiconductor structure includes an oxidizing layer constructed from materials that can be oxidized during a lithographic process so as to create an oxide aperture. The semiconductor structure further includes a number of layers near the oxidizing layer. A passivation material is disposed on the layers near the oxidizing layer. The passivation material is configured to inhibit oxidation of the layers.

Abstract: The embodiment relates to a semiconductor light-emitting device comprising a semiconductor substrate, a first cladding layer, an active layer, a second cladding layer, a contact layer, and a phase modulation layer located between the first cladding and active layers or between the active and second cladding layers. The phase modulation layer comprises a basic layer and plural first modified refractive index regions different from the basic layer in a refractive index. In a virtual square lattice set on the phase modulation layer such that the modified refractive index region is allocated in each of unit constituent regions constituting square lattices, the modified refractive index region is arranged to allow its gravity center position to be separated from the lattice point of the corresponding unit constituent region, and to have a rotation angle about the lattice point according a desired optical image.

Abstract: A laser light source device having a simple configuration and an inspection device are provided. A laser light source device 200 according to an exemplary embodiment in accordance with the present invention has a repetition frequency of 1 MHz or higher, and includes fundamental wave generation means 201 for oscillating laser light including a fundamental wave with its center wavelength being included in one of first to fourth wavelength bands, and means 205 for generating a sixth harmonic of pulsed laser light extracted from the fundamental wave generation means 201. The first wavelength band is 1064.326 nm to 1064.511 nm. The second wavelength band is 1064.757 nm to 1064.852 nm. The third wavelength band is 1063.805 nm to 1063.878 nm. Further, the fourth wavelength band is 1063.962 nm to 1064.031 nm.

Abstract: III-V lasers integrated with silicon photonic circuits and methods for making the same include a three-layer semiconductor stack formed from III-V semiconductors on a substrate, where a middle layer has a lower bandgap than a top layer and a bottom layer; a mirror region monolithically formed at a first end of the stack, configured to reflect emitted light in the direction of the stack; and a waveguide region monolithically formed at a second end of the stack, configured to transmit emitted light.

Abstract: Methods for characterizing atmospheric turbulence along an optical path from a laser transmitter to a laser receiver can include the steps of counting the number of laser speckles at the receiver imaging plane, and then finding Fried's parameter r0 using the counting result to characterize the turbulence along the path. Before counting speckles, images at the receiver image plane can be preprocessed by capturing the images. The captured images at the image plane can then be blurred and a threshold can be chosen so that only certain pixels in the image are further processed. The thresholding can be via Otsu's methods or via variants of a Gaussian fit. Kostelec's method can then be used to count speckles in the portions of the image that have made it through the thresholding step. Other counting methods could be used. Fried's can then be found using the speckle count.

Abstract: A quantum cascade laser includes a substrate including first and second regions arranged along a first axis; a stacked semiconductor layer disposed in the second region, the stacked semiconductor layer having an end facet located on a boundary between the first and second regions, the stacked semiconductor layer including a core layer and a cladding layer that are exposed at the end facet thereof; and a distributed Bragg reflection structure disposed in the first region, the distributed Bragg reflection structure including a semiconductor wall and a covering semiconductor wall that covers the end facet of the stacked semiconductor layer. The semiconductor wall and the covering semiconductor wall are made of a single semiconductor material. The semiconductor wall provides first and second side surfaces. The covering semiconductor wall provides an end facet that is located away from the first and second side surfaces of the semiconductor wall.

Abstract: A wavelength-tunable vertical-cavity surface-emitting laser (VCSEL) with the use of microelectromechanical system (MEMS) technology is provided as a swept source for Optical Coherence Tomography (OCT). The wavelength-tunable VCSEL comprises a bottom mirror of the VCSEL, an active region, and a MEMS tunable upper mirror movable by electrostatic deflections. The bottom mirror comprising a GaAs based distributed Bragg reflector (DBR) stack, and the active region comprising multiple stacks of GaAs based quantum dot (QD) layers, are epitaxially grown on a GaAs substrate. The MEMS tunable upper mirror includes a membrane part supported by suspension beams, and an upper mirror comprising a dielectric DBR stack. The MEMS tunable quantum dots VCSEL can cover an operating wavelength range of more than 100 nm, preferably with a center wavelength between 250 and 1950 nm, and the sweeping rate can be from a few kHz to hundreds of kHz, and up to a few MHz.

Abstract: A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

Abstract: A tunable distributed feedback (DFB) semiconductor laser based on a series mode or a series and parallel hybrid mode. A grating structure of the laser is a sampling Bragg grating based on the reconstruction-equivalent chirp technology. DFB lasers with different operating wavelengths based on the reconstruction-equivalent chirp technology are integrated together by a sampling series combination mode or a series/parallel hybrid mode, one of the lasers is selected to operate via a current, and the operating wavelength of the laser can be controlled by adjusting the current or the temperature, so that the continuous tuning of the operating wavelengths of the lasers can be realized. Various wavelength signals in parallel channels are coupled and then output from the same waveguide. An electrical isolation area (1-11) is adopted between lasers connected in series or lasers connected in series and connected in parallel to reduce the crosstalk between adjacent lasers.

Abstract: An optically pumped semiconductor disk laser including a pump light source, at least one semiconductor body (2), which semiconductor body (2) has at least one window region (8), an active region (7) and a reflection device (P), which reflection device has at least one first P-reflection element (P1) for the pump wavelength. The first P-reflection element (P1) is embodied and arranged such that pump light emerging from the pump light source (3) can be guided for at least two passes through the active region (7). A total thickness of the active region (7) and of the window region (8) in the direction of an optical axis of the semiconductor disk laser is less than three times the laser wavelength in the active region (7).

Abstract: A method for producing a semiconductor light receiving device includes the steps of growing a stacked semiconductor layer on a principal surface of a substrate, the stacked semiconductor layer including a light-receiving layer having a super-lattice structure, the super-lattice structure including a first semiconductor layer and a second semiconductor layer that are stacked alternately; forming a mask on the stacked semiconductor layer; forming a mesa structure on the substrate by etching the stacked semiconductor layer using the mask so as to form a substrate product, the mesa structure having a side surface exposed in an atmosphere; forming a fluorinated amorphous layer on the side surface of the mesa structure by exposing the substrate product in fluorine plasma; and after the step of forming the fluorinated amorphous layer, forming a passivation film containing an oxide on the side surface of the mesa structure.

Abstract: A device for measuring and characterizing solid-state devices or integrated circuits at RF frequencies up to 1.0 THz and beyond is provided that includes a transmitting photomixing probe structure and a receiving photomixing probe structure. The transmitting photomixing probe structure and the receiving photomixing probe structure are ac-coupled to the solid-state device or integrated circuit in a contact-free manner.

Abstract: Waveguides and electromagnetic cavities fabricated in hyperuniform disordered materials with complete photonic bandgaps are provided. Devices comprising electromagnetic cavities fabricated in hyperuniform disordered materials with complete photonic bandgaps are provided. Devices comprising waveguides fabricated in hyperuniform disordered materials with complete photonic bandgaps are provided. The devices include electromagnetic splitters, filters, and sensors.

Abstract: A mode locked semiconductor disk laser with an output beam having an ultra-short pulse length which provides the incident beam to a non linear microscope. The wavelength of the beam is at or near the action cross section maximum absorption wavelength for creating two photon excited fluorescence of a fluorescent biological marker in a sample. Semiconductor disk lasers combine excellent beam quality and output power, stability while maintaining simplicity and easiness of operation. In addition, these types of lasers are ideally suited for mass production as they are built in wafer-scale technology enabling a high level of integration. Importantly this non expensive, turn-key, compact laser system could be used as a platform to develop portable non-linear bio-imaging devices for clinical studies, facilitating its wide-spread adoption in “real-life” applications.

Abstract: Concatenated distributed feedback lasers having multiple laser sections laid out in series are disclosed. The concatenated distributed feedback lasers utilize quantum cascade core designs to produce optical gain in the mid-infrared region and may generate several wavelengths simultaneously or sequentially. Methods of making along with methods of using such devices are also disclosed.

Abstract: A method provides acceptable performance from a semiconductor transmitter photonic integrated circuit (TxPIC) that contains a plurality of modulated sources each comprising a laser source and an external modulator where each laser source provides a different emission wavelength and each modulated source forms a separate signal channel, comprising the steps of providing at least some of the signal channels with an extended identical active layer (EIAL) so that the modulated sources each have an identical active region wavelength and detuning the laser emission wavelength in each laser source within the EIAL from the laser active region wavelength.

Abstract: A vertical cavity surface emitting laser includes: a substrate; a first mirror layer; an active layer; a second mirror layer; a current constriction layer; a first area connected to the first mirror layer and including a plurality of oxide layers; and a second area connected to the second mirror layer and including a plurality of oxide layers. The first mirror layer, the active layer, the second mirror layer, the current constriction layer, the first area, and the second area configure a laminated body. The laminated body includes a first portion, a second portion, and a third portion between the first portion and the second portion. When a width of the oxide area is W1 and a width of an upper surface of the first portion is W2, W2/W1?3.3.

Abstract: A light-trapping sheet of the present disclosure includes: a light-transmitting sheet; and light-coupling structures arranged in an inner portion of the light-transmitting sheet. The light-coupling structure includes first, second and third light-transmitting layers. A refractive index of the first and second light-transmitting layers is smaller than that of the light-transmitting sheet; and a refractive index of the third light-transmitting layer is larger than those of the first and second light-transmitting layers. The third light-transmitting layer has a diffraction grating parallel to the surfaces of the light-transmitting sheet. The light-trapping sheet further includes a transparent cover sheet opposing at least one of the surfaces of the light-transmitting sheet with a gap interposed therebetween.

Abstract: The present disclosure generally pertains to optical communication apparatuses having field-tunable power characteristics. In one exemplary embodiment, an optical communication apparatus has an optical transmitter. The optical transmitter is coupled to logic that receives a user input indicative of a desired transmit mode for the transmitter, and the logic then dynamically tunes the transmitter's output power according to the selected transmit mode. In addition, the optical communication apparatus may have an optical receiver for receiving optical signals. The sensitivity of the receiver is controlled by a bias voltage that is applied to the receiver by the logic. The logic is configured to receive a user input indicative of a desired receive mode and then to tune the receiver's sensitivity via the bias voltage according to the selected receive mode.

Abstract: Re-emitting semiconductor constructions (RSCs) for use with LEDs, and related devices, systems, and methods are disclosed. A method of fabrication includes providing a semiconductor substrate, forming on a first side of the substrate a semiconductor layer stack, attaching a carrier window to the stack, and removing the substrate after the attaching step. The stack includes an active region adapted to convert light at a first wavelength ?1 to visible light at a second wavelength ?2, the active region including at least a first potential well. The attaching step is carried out such that the stack is disposed between the substrate and the carrier window, which is transparent to the second wavelength ?2. The carrier window may also have a lateral dimension greater than that of the stack. The removal step is carried out so as to provide an RSC carrier device that includes the carrier window and the stack.

Abstract: A Mach-Zehnder modulator (MZM) is horizontally integrated with a VCSEL. The horizontally-integrated MZM overcomes wavelength dependence problems of horizontally-integrated EA modulators and yet has the same advantages as horizontally-integrated EA modulators in terms of overcoming the ER and modulation range problems associated with the vertically-integrated EA and EO modulators. By overcoming these problems with the existing integrated modulators, the operation speed of the VCSEL is increased and the modulation signal range is extended to allow a wider range of modulation signals and modulation schemes, including large-signal digital modulation schemes.

Abstract: In the semiconductor laser including a diffraction grating in which a first diffraction grating region with a first pitch, a second diffraction grating region with a second pitch and a third diffraction grating region with the first pitch, an anti-reflection film coated on an end facet to the light-emitting side, and a reflection film coated on an opposite end facet, the first diffraction grating region is greater than the third diffraction grating region, and the second diffraction grating region is formed, in such a manner that phases of the first and third diffraction grating regions are shifted in a range of equal to or more than 0.6 ? to equal to or less than 0.9 ?, phases are successive on a boundary between the first and second diffraction grating regions and the phases are successive on a boundary between the second and third diffraction grating regions.

Abstract: A thermal barrier coating having a reduced high temperature thermal conductivity includes group II germanate constructs. This thermal barrier coating may be applied directly to a substrate, applied to a bond-coated substrate, and/or incorporated into a protective coating including one or more other thermal barrier coating layers. The thermal barrier coating provides improved thermal protection properties over current industry standards and materials considered for thermal protection applications.

Abstract: One embodiment relates to a pillar-supported array of micro electron lenses. The micro-lens array includes a base layer on a substrate, the base layer including an array of base electrode pads and an insulating border surrounding the base electrode pads so as to electrically isolate the base electrode pads from each other. The micro-lens array further includes an array of lens holes aligned with the array of base electrode pads and one or more stacked electrode layers having openings aligned with the array of lens holes. The micro-lens array further includes one or more layers of insulating pillars, each layer of insulating pillars supporting a stacked electrode layer. Another embodiment relates to a method of fabricating a pillar-supported array of micro electron lenses. Other embodiments, aspects and features are also disclosed.

Abstract: The invention relates to a method and a device for three-dimensional measurement of an object. The device includes a laser source for generating an illumination beam, a focusing optics for focusing the illumination beam on at least one measuring point on a surface of the object to be measured, a detector for detecting an observation beam reflected by the surface of the object, a confocal observation optics which allows only the observation beam that is focused on the surface of the object to pass through to the detector. The laser source includes multiple coherent laser elements, the laser elements simultaneously emitting illumination beams that are focused on multiple measuring points on the surface of the object, so that the laser elements are arranged to reduce the speckle effect in the 3D-image data generated by the measurement.

Abstract: A monolithically integrated, tunable semiconductor laser with an optical waveguide, comprising a laser chip having epitaxial layers on a substrate and having first and second reflectors bounding an optical gain section and a passive section, wherein at least one of the reflectors is a distributed Bragg reflector section comprising a grating and configured to have a tunable reflection spectrum, wherein the laser is provided with a common earth electrode, wherein control electrodes are provided on the optical waveguide in at least the optical gain section and the at least one distributed Bragg reflector section, wherein the passive section is provided with an electrode or electrical tracking on the optical waveguide, the passive section is configured not to be drivable by an electrical control signal, and no grating is present within the passive section.

Abstract: A monolithically integrated, tunable semiconductor laser with an optical waveguide, comprising epitaxial layers on a substrate and having first and second reflectors bounding an optical gain section and a non-driven region, wherein at least one of the reflectors is a distributed Bragg reflector section configured to have a tunable reflection spectrum, wherein control electrodes are provided to at least the optical gain section, and the distributed Bragg reflector section, and wherein the non-driven region has a length of at least 100 ?m, is without an electrical contact directly contacting onto the epitaxially grown side of the non-driven region, and the non-driven region is without a reflective Bragg grating within the epitaxial layers of the non-driven region.

Abstract: A wavelength-tunable vertical-cavity surface-emitting laser (VCSEL) with the use of microelectromechanical system (MEMS) technology is provided as a swept source for Optical Coherence Tomography (OCT). The wavelength-tunable VCSEL comprises a bottom mirror of the VCSEL, an active region, and a MEMS tunable upper mirror movable by electrostatic deflections. The bottom mirror comprising a GaAs based distributed Bragg reflector (DBR) stack, and the active region comprising multiple stacks of GaAs based quantum dot (QD) layers, are epitaxially grown on a GaAs substrate. The MEMS tunable upper mirror includes a membrane part supported by suspension beams, and an upper mirror comprising a dielectric DBR stack. The MEMS tunable quantum dots VCSEL can cover an operating wavelength range of more than 100 nm, preferably with a center wavelength between 250 and 1950 nm, and the sweeping rate can be from a few kHz to hundreds of kHz, and up to a few MHz.

Abstract: A semiconductor laser that includes a single mode semiconductor laser coupled to a flared power amplifier is provided, the device including an internal or an external optical element that reinforces the curved wave front of the flared section of the device through phase-matching. By reinforcing the curved wave front via phase-matching, the device is less susceptible to thermal and gain-index coupled perturbations, even at high output powers, resulting in higher beam quality. Exemplary phase-matching optical elements include a grating integrated into the flared amplifier section; an intra-cavity, externally positioned binary optical element; and an intra-cavity, externally positioned cylindrically curved optical element.

Abstract: An optical signal transmitting device includes direct modulators configured to be driven using electric signals of channels to generate directly-modulated optical signals of channels, a beat light source configured to generate beat light at a specific frequency spacing, subcarrier converters configured to modulate, using the beat light from the beat light source, the directly-modulated optical signals of the channels from the direct modulators to generate optical subcarrier modulation signals of channels, probe light sources configured to generate probe light of channels having frequencies that are different from frequencies of the directly-modulated optical signals of the channels, multiplexers configured to multiplex, for individual channels, the optical subcarrier modulation signals of the channels with the probe light of the channels, and nonlinear optical media configured to perform, for individual channels, optical cross modulation for the optical subcarrier modulation signals and the probe light, which

Abstract: Described are embodiments of hybrid optical apparatuses including anti-resonant optical waveguides, and methods for making such apparatuses and systems. In one embodiment, a hybrid optical apparatus may include a first semiconductor region including an active region of one or more layers of semiconductor materials and a second semiconductor region coupled with the first semiconductor region. The second semiconductor region may include an optical waveguide configured to transmit light inputted by a light input component. The optical waveguide may be defined by a first trench disposed on a first side of the waveguide, and a second trench disposed on a second side of the waveguide opposite the first side. A width of each trench may vary along a length of the apparatus to control optical power density of the light transmitted along the optical waveguide. Other embodiments may be described and/or claimed.

Abstract: A X-ray waveguide includes a core for guiding X-rays having a wavelength band in which the real part of refractive index of material is smaller than 1 and a cladding for confining the X-rays in the core. The core has a one-dimensional periodic structure in which a plurality of layers respectively formed of inorganic materials having different real parts of refractive index are periodically laminated. The core and the cladding are configured so that a critical angle for total reflection for the X-rays at an interface between the core and the cladding is larger than a Bragg angle due to a periodicity of the one-dimensional periodic structure. A critical angle for total reflection for the X-rays at an interface between layers in the one-dimensional periodic structure is smaller than the Bragg angle due to the periodicity of the one-dimensional periodic structure.

Abstract: Optically pumped laser structures incorporate reflectors that have high reflectivity and are bandwidth limited to a relatively narrow band around the central laser radiation wavelength. In some cases, the reflectors may be ¾-wavelength distributed Bragg reflectors (DBRs).

Abstract: The present invention relates to an optical element for VECSELs or VECSEL arrays. The optical element is formed of a substrate (200) which is transparent at least in a wavelength region of optical radiation. A first interface of the substrate (200) comprises one or several curved regions forming part of an optical lens or of an array of optical lenses (220) integrated in the substrate (200). The substrate (200) further comprises one or several optical mirrors (210) formed on a second interface of the substrate (200) opposing the first interface or embedded in the substrate (200). The optical mirrors (210) are arranged and designed to back reflect a fraction of optical radiation incident on the first or second interface. The optical mirrors (210) are flat mirrors or curved mirrors having a radius of curvature different from the radius of curvature of the curved region (220).

Abstract: A light emitting device is disclosed. The light emitting device includes a first-conductive-type semiconductor layer, a second-conductive-type semiconductor layer, and an active layer interposed between the first-conductive-type semiconductor layer and the second-conductive-type semiconductor layer. The second-conductive-type semiconductor layer includes an electron blocking region closely disposed to the active layer and having a pattern with a plurality of elements spaced apart from each other.

Abstract: A system and method for providing laser diodes with broad spectrum is described. GaN-based laser diodes with broad or multi-peaked spectral output operating are obtained in various configurations by having a single laser diode device generating multiple-peak spectral outputs, operate in superluminescene mode, or by use of an RF source and/or a feedback signal. In some other embodiments, multi-peak outputs are achieved by having multiple laser devices output different lasers at different wavelengths.

Abstract: Disclosed are a nitride semiconductor light-emitting element having a superior current spreading effect as a result of using a current spreading part containing current spreading impurities, and a method for manufacturing same. The nitride semiconductor light-emitting element according to the present invention comprises: an n-type nitride layer; a current spreading part, which is formed from nitride comprising current spreading impurities, and which is disposed on the n-type nitride layer; an activation layer disposed on the current spreading part; and a p-type nitride layer disposed on the activation layer, wherein the current spreading impurities comprise carbon (C).

Abstract: Semiconductor lasers comprise a substrate; an active layer configured to generate transverse magnetic (TM) polarized light under an electrical bias; an upper cladding layer; a lower cladding layer; and a distributed feedback (DFB) grating defined by the interface of a layer of metal and a layer of semiconductor under the layer of metal, the interface periodically corrugated in the longitudinal direction of the laser with a periodicity of ?DFB=m?/(2neff), wherein m>1. The DFB grating is configured such that loss of one or more antisymmetric longitudinal modes of the laser structure via absorption to the DFB grating is sufficiently maximized so as to produce lasing of a symmetric longitudinal mode of the laser with laser emission characterized by a single-lobe beam along each direction defined by the grating diffraction orders corresponding to emission away from the plane of the grating.

Abstract: The present invention provides for a semiconductor laser having a narrow linewidth and low power consumption for optical communication applications. According to various embodiments of the invention, a semiconductor laser is provided which includes a grating layer comprising a plurality of segmented gratings, each including a non-grating portion and a grating portion. The segmented gratings are configured to enhance a fundamental mode of the semiconductor laser while sufficiently suppressing modes other than the fundamental mode, providing a narrow linewidth for example. The segmented gratings are also configured to provide an effective length longer than an actual length of the semiconductor laser, leading to smaller device areas and corresponding lower power consumption. A photonic integrated circuit is also provided which includes a plurality of semiconductor lasers, consistent with the present invention, as well as additional optical elements, all provided on a single substrate.

Abstract: A method of fabrication of barrier diode based infrared detectors, utilizing the growth of unstrained, not relaxed III-V compound semiconductor material layers having a lattice constant over 6 Angstrom, is provided. The growth is performed by the means of Molecular Beam Epitaxy (MBE) or Metal-Organic Vapor Phase Epitaxy (MOVPE). The method comprises the use of bulk crystalline substrates and the growth of a transitional layer of GaInAsSb with graded composition, followed by an optional thick layer of GaInAsSb of constant composition, lattice matched to the said III-V compound semiconductor material layers, the said optional layer of GaInAsSb of constant composition serving as a virtual substrate. The method provides high crystalline quality layers suitable for semiconductor device fabrication that can effectively interact with electromagnetic radiation of the mid-infrared spectral range with a wavelength between about 2 micrometers to about 16 micrometers.

Abstract: An apparatus comprising an optical medium, a power splitter coupled to the optical medium, a first delay line coupled to the power splitter such that the power splitter is positioned between the first delay line and the optical medium, a first comb reflector coupled to the first delay line such that the first delay line is positioned between the first comb reflector and the power splitter, and a second comb reflector coupled to the power splitter but not the first comb reflector and not the first delay line. A method comprising receiving an optical signal, splitting the optical signal into a first split optical signal and a second split optical signal, delaying the first split optical signal, tuning the delayed first split optical signal, tuning the second split optical signal, and delaying the tuned second split optical signal.

Abstract: The invention relates to an optical resonator, laser apparatus and a method of generating a laser beam inside an optical resonator. The optical resonator (100) includes an optical cavity (102) and an optical element (104.1, 104.2) at either end thereof, operable to sustain a light beam (108) therein, characterized in that each optical element (104.1, 104.2) is a phase-only optical element operable to alter a mode of the beam (108) as it propagates along the length of the optical resonator (100), such that in use the beam (108) at one end of the optical resonator (100) has a Gaussian profile while the beam (108) at the other end of the optical resonator (100) has a non-Gaussian profile.

Abstract: The wavelength tunable laser includes a thermo-electric cooler (TEC), a distributed feedback portion, and a semiconductor optical amplifier (SOA). The distributed feedback portion is disposed on the thermo-electric cooler and has a plurality of distributed feedback (DFB) lasers connected in series. Each DFB laser is configured to output an optical signal within a different temperature dependent tunable range of wavelengths. Therefore, the distributed feedback portion outputs an optical signal from one of the DFB lasers. The SOA is optically connected to the distributed feedback portion. The SOA amplifies and modulates the optical signal outputted from the distributed feedback portion.

Abstract: The present technology relates to a fast and efficient heating element based on a thick heterostructure which is monolithically integrated in close proximity to one or more components of a photonic or an electronic circuit. Inventive embodiments also relate to methods of use illustrative heating elements to control or tune the characteristics of the electronic or photonic component(s). Inventive embodiments may be particularly useful in the fast spectral tuning of the emission wavelength of single mode QCLs.

Abstract: The present disclosure relates to a tunable laser module including a light gain area unit for outputting an optical signal; an optical distributor for separating the optical signal output from the light gain area unit; two comb reflection units for reflecting a part of optical signals separated by the optical distributor and allow a part of the optical signals to penetrate; two phase units for changing phases of the optical signals penetrating the two comb reflection units; an optical coupler for combining the optical signals of which the phases are changed by the two phase units; and an optical amplifier for amplifying the optical signal combined by the optical coupler, wherein the light gain area unit oscillates a laser by totally reflecting the optical signals reflected by the two comb reflection units.

Abstract: A tunable DBR laser including: an amplifier section, a part-reflecting optical output, a connection section connected to the amplifier section, and at least two wavelength-selective reflectors optically coupled to the amplifier section via the connection section. The connection section includes at least one MMI coupler and several waveguides, so that different optical paths lead from the amplifier section to the wavelength-selective reflectors and each of the different optical paths leads through the at least one MMI coupler and through one of the waveguides. The wavelength-selective reflectors differ from one another by having different reflection spectra and each of the wavelength-selective reflectors is connected to one of several outputs of the at least one MMI coupler. By activating a phase shifter, arranged in a course of at least one of the waveguides, the DBR laser can be switched between different resonators.

Abstract: A distributed feedback (DFB) laser includes a substrate of a compound semiconductor material, and quantum-well (QW) active layer(s) overlying the substrate. A p-doped cladding layer including the compound semiconductor material is on one side of the active layer and an n-doped cladding layer is on the other side. A grating is in one of the cladding layers configured to select an operating wavelength for the DFB laser. A waveguide structure in the n-doped cladding layer includes a waveguide layer of a first composition compositionally different from the compound semiconductor material having an optical thickness of 0.7 to 1.5 of the guided wavelength. The waveguide structure can further include a hetero-waveguide stack including a plurality of alternating compositional layers beyond the waveguide layer each having a thickness between one quarter and one half the guided wavelength alternating the compound semiconductor material with a second composition defining a composition wavelength.

Abstract: A tunable DBR laser including: an amplifier section, a part-reflecting optical output, a connection section connected to the amplifier section, and at least two wavelength-selective reflectors optically coupled to the amplifier section via the connection section. The connection section includes at least one MMI coupler and several waveguides, so that different optical paths lead from the amplifier section to the wavelength-selective reflectors and each of the different optical paths leads through the at least one MMI coupler and through one of the waveguides. The wavelength-selective reflectors differ from one another by having different reflection spectra and each of the wavelength-selective reflectors is connected to one of several outputs of the at least one MMI coupler. By activating a phase shifter, arranged in a course of at least one of the waveguides, the DBR laser can be switched between different resonators.

Abstract: Distributed feedback-laser diodes are provided. The distributed feedback-laser diode may include a substrate, a lower cladding layer having a grating on the substrate, an active layer disposed on the lower cladding layer, a first upper cladding layer disposed on the active layer, a phase-shift region extending in a first direction on the first upper cladding layer, and a ridge waveguide layer extending in a second direction crossing the first direction on the phase-shift region.

Abstract: A method for manufacturing a distributed feedback laser array includes: forming a bottom separate confinement layer on a substrate; forming a quantum-well layer on the bottom separate confinement layer; forming a selective-area epitaxial dielectric mask pattern on the quantum-well layer; forming a top separate confinement layer on the quantum-well layer through selective-area epitaxial growth using the selective-area epitaxial dielectric mask pattern, the top separate confinement layer having different thicknesses for different laser units; removing the selective-area epitaxial dielectric mask pattern; forming an optical grating on the top separate confinement layer; and growing a contact layer on the optical grating. The present disclosure achieves different emission wavelengths for different laser units without significantly affect emission performance of the quantum-well material.