Abstract: A simple and compact laser resonator is proposed which makes it possible to symmetrically operate a gain medium, preferably a semiconductor, which possesses more than one channel of emission. As a result higher output powers and/or better beam qualities and/or better spectral characteristics can be achieved. The resonator is very compact and ideally comprises only three optical elements: a laseractive gain medium (1), a cylindrical collimation lens (5), and a prism (6) which is adapted to the angle between the two emissions (4) and which carries a beam splitter (7) and a feedback mirror (9) on its faces. Preferably the gain medium (1) possesses a feedback element (2) and an antireflective coating (3) on its faces. If no antireflective coating (11) is desired the same effect can be achieved by arranging the angle of incidence to fulfill the Brewster-condition.

Abstract: The present invention provides a low-cost, high-bandwidth optical laser array where subsequent streams of data are injected in a serial fashion. The invention permits the creation of multiple channels of data on a single optical substrate without the use of costly multiplexer arrays to consolidate various optical signals. Further, the serial array eliminates the need for the parallel alignment of optical data sources, such as lasers, and instead allows for the serial alignment of the optical data sources, resulting in decreased footprint applications.

Abstract: Provided is a distributed feedback semiconductor laser structure including: a first clad layer; a first ridge waveguide formed on the first clad layer; an active layer formed on the first ridge waveguide; a second ridge waveguide formed on the active layer; a second clad layer formed on the second ridge waveguide; an ohmic contact layer formed on the second clad layer; and a plurality of gratings formed in at least one of the first and second clad layers, making a predetermined angle with the first ridge waveguide or the second ridge waveguide, and periodically arranged in a longitudinal direction of the first or second ridge waveguide. As a result, a general hologram lithography process capable of mass production is applied to the present invention so that process time can be reduced. Also, a distributed feedback semiconductor laser structure using a quantum-dot active layer that does not require an additional process for obtaining a pure single-wavelength is provided.

Abstract: A Distributed Bragg Reflector (DBR) that has relatively low light absorption, relatively low electrical resistance, and/or relatively good thermal conductivity. The DBR may include a first mirror layer and a second mirror layer, with an interface therebetween. A step transition is provided in the aluminum concentration and in the doping concentration at or near the interface between the first mirror layer and the second mirror layer. To reduce optical absorption, the interface between the first and second mirror layers may be positioned at or near a null in the optical electric field within the DBR. A graded junction may also be provided. The graded junction may be more lightly doped, have a graded aluminum concentration, and may be placed at or near a peak in the optical electric field.

Abstract: A semiconductor laser module includes a distributed-feedback laser. When a predetermined transmission loss, a predetermined number of channels, and a predetermined modulation factor per channel are given, a cavity length of the distributed-feedback laser satisfies a condition that a distortion is less than a predetermined distortion level and a carrier-to-noise ratio is more than a predetermined value based on a relation between transmission loss, number of channels, modulation factor per channel, and the cavity length of the distributed-feedback laser.

Abstract: A second-order multi-mode partial distributed feedback (p-DFB) laser having increased electrical-to-optical power conversion efficiency, stabilized wavelength and narrowed emission linewidth. The laser includes an abbreviated grating housed in the laser cavity that is separated from both the front-end and the back-end of the laser facets.

Abstract: A distributed feedback semiconductor laser may have (1) a controlled complex-coupling coefficient which is not affected by grating etching depth variation, and (2) facet power asymmetry with no facet reflection which eliminates a random effect of facet grating phase. The device comprises a multiple-quantum-well active region, and a complex-coupled grating formed by periodically etching grooves through a part of the active region. The semiconductor materials for a barrier layer where the groove etching is to be stopped, a regrown layer in the etched groove, and a laser cladding layer, are chosen all the same, so as to form an active grating entirely buried in the same material, providing a complex-coupling coefficient which is defined independently of the etching depth. Facet power symmetry may also be provided by composing the laser cavity of two sections (“front” and “back” sections) having different (“front” and “back”) Bragg wavelengths.

Abstract: A semiconductor laser is a distributed feedback semiconductor laser in which the lasing wavelength can be changed, and includes a semiconductor substrate and a semiconductor layer portion provided on the substrate and including first and second active layers and an intermediate layer that optically couples the first active layer and the second active layer. The first active layer, the intermediate layer, and the second active layer are arranged in that order in a predetermined axis direction. The semiconductor laser further includes a diffraction grating that is optically coupled with the first and second active layers of the semiconductor layer portion, a first electrode and a second electrode for injecting carriers into the first active layer and the second active layer, respectively, and a third electrode for supplying the intermediate layer with a current. The grating extends in the predetermined axis direction and has a period that is uniform in the predetermined axis direction.

Abstract: A vertical-cavity surface-emitting laser incorporating a supported air gap distributed Bragg reflector is disclosed. The supported air gap DBR includes a regrowth layer of material that provides mechanical support for the original material layers. The supported air gap DBR is fabricated by first growing alternating pairs of a first material and a sacrificial material over a suitable substrate. The layer pairs of the first material and sacrificial material are covered by a suitable dielectric material. The dielectric material is then selectively removed exposing regions of the first material and sacrificial material where selective regrowth of additional material is desired. The selective regrowth of the additional material provides mechanical support for the semiconductor material that remains after a selective etch removal of the sacrificial material.

Abstract: A Distributed Feed-Back (DFB) laser integrated with an Electroabsorption (EA) modulator whose facet at the end of EA modulator section has finite reflectively to create adiabatic chirp by optical feedback to the DFB laser.

Abstract: A quantum dot laser operates on a quantum dot ground-state optical transition. The laser has a broadband (preferably ?15 nm) spectrum of emission and a high output power (preferably ?100 mW). Special measures control the maximum useful pump level, the total number of quantum dots in the laser active region, the carrier relaxation to the quantum dot ground states, and the carrier excitation from the quantum dot ground states. In one embodiment, a spectrally-selective loss is introduced into the laser resonator in order to suppress lasing on a quantum dot excited-state optical transition, thereby increasing the bandwidth of the emission spectrum.

Abstract: A distributed feedback (DFB) quantum dot semiconductor laser structure is provided. The DFB quantum dot semi-conductor laser structure includes: a first clad layer formed on a lower electrode; an optical waveguide (WG) formed on the first clad layer; a grating structure layer formed on the optical WG and including a plurality of periodically disposed gratings; a first separate confinement hetero (SCH) layer formed on the grating structure layer; an active layer formed on the first SCH layer and including at least a quantum dot; a second SCH layer formed on the active layer; a second clad layer formed on the second SCH layer; an ohmic layer formed on the second clad layer; and an upper electrode formed on the ohmic layer. Accordingly, an optical WG is disposed on the opposite side of the active layer from the grating structure layer, thereby increasing single optical mode efficiency.

Abstract: The present invention relates to an analog transmitter using an external cavity laser (ECL) in which specific characteristics of the ECL are enhanced and exploited to improve 2nd and 3rd order distortion while increasing the threshold for the occurrence of deleterious stimulated Brillouin scattering (SBS). The performance of the ECL shows a substantial reduction in distortion occurring over certain narrow ranges of operating temperatures. Optical, electronic, thermal and/or mechanical methods are described that cause this “distortion dip” to be moved to, or created at, stable regions of ECL operation, away from mode hops. Methods are also described that allow the distortion dip to be moved to, or created at, ECL operating regions in which sufficiently high chirp occurs, thereby reducing SBS. Transmitters and other devices employing these and related techniques are also described.

Abstract: A surface-emitting photonic device including a structure disposed therein to enhance a performance thereof. The structure includes a two dimensionally periodic second order distributed feedback device (DFB) to emit diffraction limited outcoupled laser light having a predetermined wavelength along a propagation direction that is substantially normal to a plane of the DFB, and a first order distributed Bragg reflector (DBR) coplanar with, adjacent to and surrounding the DFB, a geometry of the DBR being selected such that a bandgap of the DBR is maximized and centered around the predetermined wavelength of the emitted light, a substrate, and either an optical gain layer, or a semi-conductor quantum well laser disposed within the substrate.

Abstract: A directly modulated distributed feedback (DFB) laser with improved optical field uniformity and mode stability may include a laser cavity and a distributed reflector and/or external reflectors. The distributed reflector may be a Bragg grating and may extend asymmetrically over a only portion of the laser cavity. The external reflectors may themselves be distributed Bragg reflectors and may have unequal reflectances. Optical field uniformity may be improved by adjusting the length and/or position of the distributed reflector in the laser cavity. Optical field uniformity may be improved by adjusting a coupling strength parameter, which is a function of a coupling coefficient, ?, and the length of the distributed reflector.

Abstract: A tuneable laser includes a gain section (50) bounded by two mirrors (51 and 52) at least one mirror being a chirp grating. At least one of the mirrors includes a plurality of selectable electrodes (59 to 65) to enable the grating to be selectively activated to produce a selective reflection at a predetermined wavelength.

Abstract: A vertical-cavity, surface-emission-type laser diode includes an optical cavity formed of an active region sandwiched by upper and lower reflectors, wherein the lower reflector is formed of a distributed Bragg reflector and a non-optical recombination elimination layer is provided between an active layer in the active region and the lower reflector.

Abstract: A gain-coupled distributed feedback (DFB) semiconductor laser includes a grating formed by grooves through at least a part of an active region of a laser cavity. The DFB laser may be configured with a substantially pure gain-coupled grating and may be configured to provide facet power asymmetry. The grating may include at least a first-order grating section and a second-order grating section. A lasing wavelength may be obtained at the Bragg wavelength of the second-order grating section by substantially eliminating index coupling in the grating. The first-order grating section may act as a reflector for the lasing wavelength, thereby producing asymmetric power distribution in the laser cavity.

Abstract: An illumination light source is provided with a laser light source having a laser medium with a specified gain region, and a reflector having a narrow band reflection characteristic. A part of a laser light emitted from the laser light source is reflected and fed back by the reflector, so that an oscillation wavelength of the laser light source is fixed at a reflection wavelength. A peak of the gain region of the laser medium is shifted from the reflection wavelength by a change of an oscillation characteristic of the laser light source, so that the oscillation wavelength of the laser light source is changed from the reflection wavelength. Thus, an oscillation spectrum of the laser light source is spread to reduce speckle noise.

Abstract: A DFB quantum cascade laser element that can reliably CW-oscillate a single-mode light even at room temperature or a temperature in proximity thereof is provided. In a quantum cascade laser element 1, a top-grating approach for which a diffraction grating 7 is formed on a laminate 3 is adopted, and thus in comparison with a buried-grating approach, deterioration in temperature characteristics of the laser element and decline in the yield and reproducibility are suppressed. In addition, since the thickness of a cladding layer 5 located between an active layer 4 and the diffraction grating 7 is within a range of 42±10% of the oscillation wavelength, weakening of light seeping from the active layer 4 to the diffraction grating 7 or an increase in light leakage is prevented. Consequently, by the quantum cascade laser element 1, a single-mode light can be reliably CW-oscillated even at room temperature or a temperature in proximity thereof.

Abstract: An optical waveguide propagates a laser beam. Main diffraction grating and sub-diffraction grating couple light propagating in the optical waveguide. The main diffraction grating and the sub-diffraction grating couple the light in such a manner that propagation in a second order transverse mode of the light propagating in the optical waveguide when both the main diffraction grating and the sub-diffraction grating are disposed, is suppressed more than propagation in the second order transverse mode of the light propagating in the optical waveguide when only the main diffraction grating is disposed.

Abstract: A double-grating excimer laser cavity is disclosed which includes a first multilayer dielectric diffraction grating comprised of a dielectric stack having a plurality of continuous layers with alternating high and low refractive indices, and a nonmetallic diffraction grating disposed on the top layer of the plurality of layers. The nonmetallic diffraction grating is a single pair of layers made of a low refractive index dielectric material and a high refractive index dielectric material. Grooves extend through the pair of layers. The diffraction grating has a diffraction efficiency of greater than 85% at the laser emission wavelength. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: Exemplary embodiments of the present invention provide optical devices including optical members whose disposed positions, shapes and sizes are excellently controlled, and methods for manufacturing the same, and to provide optical modules and optical transmission devices that include the aforementioned optical devices. An optical device of the exemplary embodiments of the present invention include a device section having an optical surface, a pointed section provided in a manner to surround the optical surface, and an optical member having at least one section that is provided on the optical surface.

Abstract: Using sampled Bragg grating structure, the present invention proposes a distributed feedback (DFB) semiconductor laser based on reconstruction-equivalent-chirp technology. Namely, the Bragg grating in the said DFB semiconductor laser cavity is a sampled Bragg grating, in which there is an equivalent grating corresponding to the original ordinary DFB grating as feedback for lasing. The laser wavelength of the said semiconductor laser located within the operation bandwidth of the said equivalent grating. The said equivalent grating is designed and fabricated using REC technology and has equivalent chirps, one equivalent phase shift or multiple equivalent phase shifts. The said sampled Bragg grating has multiple ghost gratings and the wavelength spacing between neighboring ghost gratings is inversely proportional to the sampling period and the effective refractive index of the said semiconductor laser.

Abstract: A two-dimensional photonic crystal formed by arranging in a lattice pattern a medium having a refractive index different from that of a medium layer formed near an active layer. The two-dimensional photonic crystal includes a distributed-feedback control photonic crystal in which a light propagating through the active layer as a core is subjected to a two-dimensional distributed feedback within a plane of the active layer, and the light is not radiated in a direction normal to the plane of the active layer, and a surface-emission control photonic crystal in which the light is radiated in the direction normal to the plane of the active layer, which are superimposed with each other.

Abstract: An alternating current light emitting device and the fabrication method includes forming one or more alternating current micro diode light emitting modules on a substrate, wherein the alternating current micro diode light emitting module has two micro diodes connected to one another, and each micro diode has at least two active layers and is electrically connected by a conductive structure, such that the active layers of each micro diode can take turns emitting light during the positive/negative half cycles of alternating current. A continuous and full-scale light emitting effect is thereby achieved.

Abstract: A distributed feedback semiconductor laser comprises a first cladding layer, a first optical guide layer, an active layer, a second optical guide layer, an InP semiconductor layer, an InGaAsP semiconductor layer, and a second cladding layer. The first optical guide layer is provided on the first cladding layer. The active layer is provided on the first optical guide layer. The second optical guide layer is provided on the active layer and made of AlGaInAs semiconductor. The InP semiconductor layer is provided on the second optical guide layer. The InGaAsP semiconductor layer is provided on the InP semiconductor layer. The second cladding layer is provided on the InGaAsP semiconductor layer and made of InP semiconductor. A diffraction grating for the distributed feedback semiconductor laser includes the InGaAsP semiconductor layer and the second cladding layer.

Abstract: A vertical cavity surface emitting laser device includes a first reflective mirror layer, a second reflective mirror layer, and an active layer disposed therebetween, wherein at least one of the first reflective mirror layer and the second reflective mirror layer includes a periodic-refractive-index structure in which the refractive index periodically changes in the in-plane direction and a part of the periodic-refractive-index structure includes a plurality of parts that disorder the periodicity.

Abstract: A sensor and method for surface plasmon resonance sensing, wherein a small variation of the refractive index of an ambient medium results in a large variation of loss of a sensing mode. The surface plasmon resonance sensor comprises an antiguiding waveguide including a core characterized by a refractive index and a reflector surrounding the core. The reflector has an external surface and is characterized by a band gap and a refractive index higher than the refractive index of the core. A coating is deposited on the external surface of the core, the coating defining with the ambient medium a coating/ambient medium interface. In operation, the coating is in contact with the ambient medium, and the antiguiding waveguide is supplied with an electromagnetic radiation to (a) propagate a mode for sensing having an effective refractive index lower than the refractive index of the core and higher than a refractive index of an ambient medium and (b) produce surface plasmons at the coating/ambient medium interface.

Abstract: In accordance with the present invention, GaAs-based optoelectronic devices have an active region that includes a well layer composed of a compressively-strained semiconductor that is free, or substantially free, of nitrogen disposed between two barrier layers composed of a nitrogen- and indium-containing semiconductor.

Abstract: A low optical loss and high efficiency grating is placed within a broad-area high-power laser diode or single spatial mode laser diode to narrow the spectral width and stabilize the emission wavelength. Several embodiments of grating configurations are presented, together with the measured results of a reduction to practice of a particular embodiment.

Abstract: An electro-optical element is provided including a light-emitting element part and a light-receiving element part, wherein an optical thickness d of the light-receiving element part satisfies the following condition: d=m?/2 where ? is a design wavelength of the light-emitting element part, and m is a natural number greater than or equal to one.

Abstract: A variable light controlling device comprising a substrate, an optical waveguide disposed on the substrate, a first heater and a second heater to change the optical waveguide's temperature is fabricated. And a total amount of the power supplied to the first and the second heater, or a total amount of heat emitted from both of the first and second heater, is maintained substantially constant. Then, the substrate is protected from temperature changes, thereby, stable and quick wavelength tuning operations are realized.

Abstract: An organic distributed feedback layer, which comprises a resonator in a double layer structure comprising a photo-induced mass transfer material layer and an organic fluorescence layer, provided as an under layer below the former layer, where the photo-induced mass transfer material is a polymer material having an azobenzene skeleton represented by the following chemical structure: has such a characteristic that the laser emission wavelength is programmable by changing interference exposure conditions for forming gratings of the photo-induced mass transfer material.

Abstract: A second-order multi-mode partial distributed feedback (p-DFB) laser having increased electrical-to-optical power conversion efficiency, stabilized wavelength and narrowed emission linewidth. The laser includes an abbreviated grating housed in the laser cavity that is separated from both the front-end and the back-end of the laser facets.

Abstract: A surface-emitting type semiconductor laser includes a substrate, a first distributed Bragg reflection type mirror formed above the substrate, an active layer formed above the first mirror, a second distributed Bragg reflection type mirror formed above the active layer, and an insulation layer having an opening section that is formed in one of the first and second mirrors, wherein light generated from the active layer is emitted as a lower order mode laser beam lower order modeor a higher order mode laser beamhigher order mode, and the first mirror is formed with a number of pairs greater than the number of pairs of the second mirror such that the lower order mode laser beamlower order mode can be emitted in an upward direction of the substrate, and the opening section in the insulation layer is formed to have a size that enables the higher order mode laser beamhigher order mode to be emitted in a downward direction of the substrate.

Abstract: A traveling-wave, surface-emitting-optical-waveguide amplifier uses Bragg gratings to provide both confinement in the lateral direction and couple light out of the waveguide plane. The grating lines are parallel to the direction of flow of the optical mode in the traveling-wave amplifier and result in emission along the entire length of the amplifier. The parallel grating does not cause feedback into the optical mode so that laser oscillation in the traveling wave amplifier is avoided. At the same time the continuous output coupling provided by the grating avoids the deleterious effect of power saturation. In this way coherent light is emitted from a very wide and long area resulting in very high power and outstanding low beam divergence. A DFB or DBR laser may be included monolithically as the power source for the amplifier and to obtain a Master-oscillator-power amplifier (MOPA) with outstanding performance.

Abstract: A light wavelength converting apparatus includes a semiconductor laser having gain, phase, and DBR regions, a nonlinear optical device for receiving fundamental-wave light emitted from the semiconductor laser and outputting second harmonic wave light, a first optical detector for monitoring output of the fundamental-wave light, a second optical detector for monitoring the second harmonic wave light, and a control portion for controlling a drive current for driving the semiconductor laser. The control portion includes a control parameter determiner and wavelength controller. The control parameter determiner changes a DBR current supplied to the DBR region and a phase current supplied to the phase region to obtain a changing point, and determines a control parameter for controlling the DBR and phase currents such that the relationship therebetween is not located on the changing point. The wavelength controller controls the DBR and phase currents pursuant to the control parameter.

Abstract: A simple and compact laser resonator is proposed which makes it possible to symmetrically operate a gain medium, preferably a semiconductor, which possesses more than one channel of emission. As a result higher output powers and/or better beam qualities and/or better spectral characteristics can be achieved. The resonator is very compact and ideally comprises only three optical elements: a laseractive gain medium (1), a cylindrical collimation lens (5), and a prism (6) which is adapted to the angle between the two emissions (4) and which carries a beam splitter (7) and a feedback mirror (9) on its faces. Preferably the gain medium (1) possesses a feedback element (2) and an antireflective coating (3) on its faces. If no antireflective coating (11) is desired the same effect can be achieved by arranging the angle of incidence to fulfill the Brewster-condition.

Abstract: A control (20) and a method of controlling a tunable laser having a gain section (4), a phase change section (5) and a segmented Bragg grating reflector section (6) comprising a series of grating units (9-17) each of a different pitch, and an electrode (9a-17a) associated with each grating so that an electrical current is applicable to each individual grating. The control (20) includes a plurality of digitally controlled sources (31, 32) of electrical current which are each connected to switch means (33 or 35, 36) operable to independently connect each of said sources (31, 32) to a respective electrode (e.g. 11a or 12a) associated with a grating (e.g. 11 or 12) which is one of a subset of consecutive gratings (e.g. 11 & 12) selected from said series of grating units (9-17).

Abstract: Provided is a self-pulsating laser diode including: a distributed feedback (DFB) section serving as a reflector; a gain section connected to the DFB section and having an as-cleaved facet at one end; a phase control section interposed between the DFB section and the gain section; and an external radio frequency (RF) input portion applying an external RF signal to at least one of the DFB section and the gain section.

Abstract: A modulation light source capable of maintaining thermal stability of a gain part is provided. A modulation light source includes a DBR laser having a DBR part, a phase part and a gain part, a light wavelength conversion device that receives a fundamental wave from the DBR laser and from which an SHG light is emitted, and a control means for controlling the DBR laser. A substantially constant current is supplied to the gain part for a modulation time period of a PWM signal. At least one of the DBR part and the phase part is controlled for modulation using a current based on the PWM signal.

Abstract: An optical structure comprising an optical resonator is provided. The optical resonator comprises a first set of nested closed optical regions, forming a distributed feedback resonator structure with a direction of radially alternating optical refractive index, and a second set of nested optical regions, forming a distributed feedback resonator structure with a direction of radially alternating optical refractive index. Each optical region of the second set is interrupted by a first gap region with a lower refractive index, wherein the first gap regions substantially overlap in the direction of radially alternating optical refractive index. The first set is arranged nested within the second set and the optical structure further comprises a first optical waveguide optically coupled to the optical resonator via a first waveguide portion reaching into the first gap regions and being arranged coplanar to the optical resonator.

Abstract: A semiconductor laser includes an active layer on an n-type InP substrate. A diffraction grating and a p-type InP cladding layer are above the active layer. The diffraction grating has at least one phase shift portion. Facets of the distributed feedback laser each have thereon an antireflective film having a reflectance of 3% or less. The diffraction grating does not extend into end regions of the distributed feedback laser, each end region extending 1 ?m-20 ?m from a respective one of the facets toward an opposite end in a waveguide direction.

Abstract: Dual-wavelength operation is easily achieved by biasing the gain section. Multiple gratings spaced apart from each other are separated from an output aperture by a gain section. A relatively low coupling coefficient, ?, in the front grating reduces the added cavity loss for the back grating mode. Therefore, the back grating mode reaches threshold easily. The space section lowers the current induced thermal interaction between the two uniform grating sections, significantly reducing the inadvertent wavelength drift. As a result, a tunable mode pair separations (??) as small as 0.3 nm and as large as 6.9 nm can be achieved.

Abstract: A quasi-monochromatic light beam carrier for a particular telecommunication channel is likely to experience drift because of age, temperature, or other factors, and may cause the centroid wavelength of the carrier to shift. Temperature adjustments by wavelength lockers to compensate for drift on one channel may affect the performance of other channels. Embodiments of the present invention couple a quasi-monochromatic light beam through a substrate-based grating, diffract the light beam from the edge of the substrate to free space, and detect the light beam from free space at a position detector to determine the centroid wavelength based on a position of the light beam incident on the detector. The diffracted light beam may be reflected within the substrate a number of times prior to exiting the substrate towards the detector.

Abstract: A method includes, for each desired wavelength of a plurality of desired output wavelengths, selecting a light-emitting resonant structure (LERS) that emits light at the desired wavelength when exposed to a beam of charged particles; and forming the periodically complex resonant structure from the selected light-emitting resonant structures.

Abstract: Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

Abstract: A frequency modulated (FM) vertical cavity surface emitting laser (VCSEL). The frequency modulated VCSEL includes a mirror region that has an active region. The frequency modulated VCSEL also includes a phase adjustment region for use in altering the characteristics of the VCSEL. For example, by changing the index of refraction in the phase adjustment region, the wavelength of the VCSEL can be changed, resulting in frequency modulation.

Abstract: A micro-lens built-in vertical cavity surface emitting laser (VCSEL) includes a substrate and a lower reflector formed on the substrate. An active layer is formed on the lower reflector, generating light by a recombination of electrons and holes. An upper reflector is formed on the active layer including a lower reflectivity than that of the lower reflector. A micro-lens is disposed in a window region through which the laser beam is emitted. A lens layer is formed on the upper reflector with a transparent material transmitting a laser beam; the lens layer includes the micro-lens. An upper electrode is formed above the upper reflector excluding the window region a lower electrode formed underneath the substrate.