Abstract: Systems and methods for electrically pumped, surface-emitting and edge emitting ZnO ultraviolet diode lasers are disclosed. The ZnO diode laser may be fabricated using growth processes (e.g., MBE) to form Sb-doped ZnO as a p-type layer and doped ZnO as an n-type layer. ZnO-based quantum well structures may be further formed in between the n- and p-type ZnO layers. The ZnO layers and quantum wells may be grown in columnar structures which act as resonant cavities for generated light, significantly improving light amplification and providing high power output. For example, ultraviolet lasing at around 380 nm was demonstrated at about room temperature at a threshold current density of about 10 A/cm2. The output power was further measured to be about 11.3 ?W at about 130 mA driving current.

Abstract: A semiconductor laser device includes a lower cladding layer; an active layer disposed on the lower cladding layer; all upper cladding layer disposed on the active layer; a diffraction-grating layer disposed on the upper cladding layer, the diffraction-grating layer including periodic projections and recesses; and a buried layer disposed on the periodic projections and recesses in the diffraction-grating layer. In addition, the diffraction-grating layer and the buried layer constitute a diffraction grating. The lower cladding layer, the active layer, and the upper cladding layer constitute a first optical waveguide, the active layer constituting a first core region in the first optical waveguide. The upper cladding layer, the diffraction-grating layer, and the buried layer constitute a second optical waveguide, the diffraction-grating layer constituting a second core region in the second optical waveguide.

Abstract: A surface emitting laser includes a cavity region formed on a group-III-V compound substrate, which includes an active layer and a current confinement layer that has an aluminum oxide compound and confines a current path through which a current is injected into the active layer, an upper DBR mirror and a lower DBR mirror formed on the substrate, sandwiching the cavity region, and a graded-composition layer disposed to contact the current confinement layer, which has an aluminum composition ratio decreasing monotonically as a distance from the current confinement layer increases. The graded-composition layer includes a first region that contacts the current confinement layer and an oxidation stop layer that contacts the first region and that has a change rate of the aluminum composition ratio larger than that of the first region. The graded-composition layer is oxidized from an interface with the current confinement layer to at least a portion of the oxidation stop layer.

Abstract: An optical noise signal is added to an optical data signal on the receiver side, and a signal quality of the data signal is determined. The magnitude of the added noise signal is varied, and a function of the signal quality of the data signal is determined in dependence on the added noise signal. Subsequently, a first straight line is approximated to the previously determined function for smaller values of the added noise signal, and a second straight line for larger values of the added noise signal. The optical signal-to-noise ratio is read from the intersecting point of the first straight line with the second straight line. Thus, the ASE present is derived from the controlled addition of additional ASEs, and the optical signal-to-noise ratio is determined. The process is particularly suited for DWDM systems because it works even with very narrow channel separations, or with narrowband optical filtration along the separation.

Abstract: Optoelectrical conversion of the received optical service signal (OSS), bandpass filtering and subsequent squaring produce a spectral line at the clock frequency (fT). This clock line (TL) is selected by means of narrowband filtering and rectified. The service signal voltage (VTLM) obtained in this manner is used to switch on a Raman pump laser (11).

Abstract: A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.

Abstract: The present invention relates to external cavity laser (ECL) apparatuses and manufacturing processes, and more particularly to implementing low noise narrow bandwidth ECLs on planar lightwave circuit (PLC) platforms for harnessing high-performance, high-stability operation from a compact-footprint, low-power packaged device. An ECL device with narrow linewidth and low noise is disclosed, the device comprising a PLC device and a gain chip butt-coupled to each other. The PLC device has a planar Bragg grating (PBG) integrated onto a rectangular waveguide. The PLC device has anti-reflection coatings (ARC) on its input facet and output facet. The waveguide is designed to be selective of a single polarization. The gain chip has high-reflection coating (HRC) on a back facet and an ARC on a front facet. An operating wavelength of the ECL is aligned to a longer wavelength red slope of a reflectivity spectrum of the PBG. The operating wavelength may be tuned thermally, electrically, or thermo-electrically.

Abstract: A vertical cavity surface emitting laser including a substrate, a first semiconductor multilayer film reflector formed on the substrate, an active region formed on the first semiconductor multilayer film reflector, a second semiconductor multilayer film reflector formed on the active region, an electrode formed on the second semiconductor multilayer film reflector, a light absorption layer, and a light transmission layer. In the electrode, a light emitting aperture is formed. The light absorption layer is formed in a peripheral region of the light emitting aperture, and absorbs emitted light. The light transmission layer is composed of a material which the emitted light can pass through, and formed in a central region of the light emitting aperture. Thicknesses of the light absorption layer and the light transmission layer are selected so that phases of light from the light absorption layer and from the light transmission layer are adjusted.

Abstract: An optoelectronic (OE) package or system and method for fabrication is disclosed which includes a silicon layer with wiring. The silicon layer has an optical via for allowing light to pass therethrough. An optical coupling layer is bonded to the silicon layer, and the optical coupling layer includes a plurality of microlenses for focusing and or collimating the light through the optical via. A plurality of OE elements are coupled to the silicon layer and electrically communicating with the wiring. At least one of the OE elements positioned in optical alignment with the optical via for receiving the light. A carrier is interposed between electrical interconnect elements. The carrier is positioned between the wiring of the silicon layer and a circuit board and the carrier is electrically connecting first interconnect elements connected to the wiring of the silicon layer and second interconnect elements connected to the circuit board.

Abstract: A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface-emitting light emitter or modulator or as an edge-emitting light emitter or modulator.

Abstract: A method and structure for producing lasers having good optical wavefront characteristics, such as are needed for optical storage includes providing a laser wherein an output beam emerging from the laser front facet is essentially unobstructed by the edges of the semiconductor chip in order to prevent detrimental beam distortions. The semiconductor laser structure is epitaxially grown on a substrate with at least a lower cladding layer, an active layer, an upper cladding layer, and a contact layer. Dry etching through a lithographically defined mask produces a laser mesa of length lc and width bm. Another sequence of lithography and etching is used to form a ridge structure with width w on top of the mesa. The etching step also forming mirrors, or facets, on the ends of the laser waveguide structures. The length ls and width bs of the chip can be selected as convenient values equal to or longer than the waveguide length lc and mesa width bm, respectively.

Abstract: A resonantly pumped, trivalent thulium ion (Tm3+) doped, crystal laser with improved efficiency is disclosed. Embodiments are pumped from the 3H6 ground state manifold to the 1st excited 3F4 state manifold by photons with wavelengths between 1.4 and 2.2 microns and laser wavelengths ranging from 1.5 to 2.4 microns arising from 3F4 to 3H6 transitions ensue, with output wavelengths dependant upon the choice of pump wavelength, crystalline host, and resonator optics.

Abstract: The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned, and to improved optical reflector assemblies for use in such optical rotary joints.

Abstract: A device for generating light pulses includes a seed laser source for generating input light pulses. An optical pre-amplifier having variable gain receives the input light pulses from the seed laser source. An optical power amplifier receives the light pulses from the optical pre-amplifier and amplifies and compresses the received light pulses. The light pulses are compressed in the optical power amplifier in such a manner that the pulse duration of the output light pulses of the optical power amplifier is tunable via adjusting the gain of the optical pre-amplifier. Wavelength-tunable light pulses are obtained by supplying the output light pulses of the optical power amplifier to a highly non-linear optical fiber.

Abstract: In a method of allocating a bandwidth of a passive optical network, downward data are transmitted by varying a wavelength based on a wavelength division method and upward data are transmitted using a time division method. Thereby, by efficiently allocating a network bandwidth, data can be transmitted and by realizing statistical multiplexing, transmission efficiency can be improved.

Abstract: Electrically pumped mid-IR semiconductor lasers that are operable at room temperature and possess a range of tunability up to 1100 nm, which constitutes a revolutionary (1-2 orders of magnitude) improvement in the range of tunability over existing semiconductor laser technology utilizing Doped quantum confined host material (DQCH) with characteristic spatial dimension of the confinement tuned to enable the overlap of the discrete levels of the host and impurity ions and efficient energy transfer from the separated host carriers to the impurity, wherein: said DQCH material has the formula TM:MeZ and/or MeX2Z4, wherein Me is selected from the group consisting of Zn, Cd, Ca, Mg, Sr, Ba, Hg, Pb, Cu, Al, Ga, In; Z is selected from the group consisting of S, Se, Te, O, N, P, As, Sb and their mixtures; X being selected from the group consisting of Ga, In, and Al; and TM is selected from the group consisting from V, Cr, Mn, Fe, Co, and Ni.

Abstract: A semiconductor laser device includes: a semiconductor laser having a reflector region, a gain region for laser oscillation and a plurality of refraction index controllers, the reflector region having a plurality of segments in which a diffraction region and a space region are coupled to each other, the plurality of segments being separated into a plurality of segment groups having a same optical length, the plurality of refractive index controllers being provided according to each segment group and controlling an equivalent refraction index of each segment group; a wavelength controller controlling an oscillation wavelength of the semiconductor laser by controlling the plurality of the refraction index controllers as at least one of control parameters; and a dither controller inputting a dither signal into only one of the segment groups having the most segments from one of the refractive index controllers according to the segment group.

Abstract: The present invention relates to a green laser generation device which can be applied to a cellular phone, and more particularly to a green laser generation device which is ultra compact in size having volume of 1 cc or less, despite having a built-in thermo electric cooler, and has sufficient output power, despite having low power consumption, and a portable electronic machine having a laser projection display using the said device. The present invention provides a green laser generation device comprising an LD pump constituted by a photo diode; a fundamental generator generating infrared light laser according to the driving of the LD pump; a second harmonic generator generating green light using the generated infrared light laser; a polarization maintenance unit inserted between the fundamental generator and the second harmonic generator to maintain the polarization of the laser; and a temperature controller controlling an internal temperature of the green laser generation device.

Abstract: To detect a wavelength drift of laser light with no error, an optical transmission module (10) includes: a laser diode (20); a laser temperature calculation section (52) for detecting the temperature of the laser diode (20) that monotonously increases with respect to a wavelength of the laser light; a wavelength calculation section (44) for detecting a transmittance of the laser light incident on an etalon filter (36) whose transmittance periodically varies with respect to the wavelength of the incident light, and a laser wavelength corresponding to the transmittance; and a wavelength error obtaining section (54) for detecting a wavelength error (wavelength drift), from a target wavelength, of the laser light output from the laser diode (20), based on the temperature detected by the laser temperature calculation section (52) and the laser wavelength detected by the wavelength calculation section (44).

Abstract: A semiconductor laser device includes a first semiconductor laser element formed on a surface of a first conductive type substrate, obtained by stacking a first conductive type first semiconductor layer, a first active layer and a second conductive type second semiconductor layer successively from the first conductive type substrate and a second semiconductor laser element obtained by successively stacking a first conductive type third semiconductor layer, a second active layer and a second conductive type fourth semiconductor layer, wherein the third semiconductor layer is electrically connected to the first semiconductor layer by bonding a side of the third semiconductor layer to the surface of the first conductive type substrate through a fusible layer.