Abstract: The preferred embodiment describes a regulating device (400) that regulates current flow through a thermoelectric cooler (TEC) (420) with higher power efficiency than conventional regulating methods. The regulating device includes a voltage controller (415) that receives an input voltage from a comparator (435) that has determined whether there has been a change in temperature surrounding a temperature sensitive device, such as a laser, by way of a thermistor (425). The controller (415) then controls two pulse width modulated (PWM) synchronous rectifiers (405, 410). The combination of the controller (415) and the synchronous rectifiers (405, 410) improves the power efficiency of the regulating device (400). Each PWM synchronous rectifier (405, 410) includes two field effect transistors (FETs) that supply substantially a constant current flow through the TEC (420) to either heat or cool a control surface (430).

Abstract: In the case of a multiple semiconductor laser structure containing a plurality of laser pn junctions stacked vertically one on top of the other, different operating temperatures of the active zones occur during operation on account of the different distance within the layer structure from a common heat sink. The displacements in the emission wavelength caused by the temperature influence are compensated by a variation of the thickness and/or material composition of the active zones, so that a narrow wavelength distribution is achieved.

Abstract: In a semiconductor laser having a ridge-shaped stripe and made of nitride III-V compound semiconductors, opposite sides of the ridge are buried with a buried semiconductor layer of AlxGa1-xAs (0<×≦1), (AlxGa1-x)yIn1-yP (0≦×≦1, 0≦y≦1) or ZnxMg1-xSySe1-y (0≦×≦1, 0≦y≦1) to stably control transverse modes, thereby minimizing higher mode oscillation during a high power output, and improving the heat dissipation property.

Abstract: A semiconductor laser with lateral optical cavity based on III-V or II-VI semiconductor compounds and their alloys is suggested. The essence of the disclosure is in the use of polygonal surface optical grating resonator (PGR) for lateral confinement of the light and selective excitation of the chosen optical mode. PGR allows fabricating of single mode semiconductor lasers needed for various applications such as CD and DVD pick up heads, high quality laser printers and others. Also, PGR allows controlled multiple wavelength operation of semiconductor lasers needed for telecommunication purposes. The technological advantage of PGR over traditional mesa-structure or ridge optical cavity resonators is in simplicity of integration of surface optical grating fabrication process into planar semiconductor technology.

Abstract: An integrated electroabsorption modulated laser (EML) device includes a distributed feedback (DFB) laser and modulator. The DFB laser includes an active layer and a complex index grating. The modulator includes an active layer. The EML device includes a first electrical contact over the DFB laser and a second electrical contact over the modulator. The EML device includes a stop etch layer above the active layer of both the DFB laser and the modulator. An electroabsorption modulated partial grating laser (EMPGL) device includes a distributed feedback (DFB) laser, an amplifier and a modulator. An ion implantation region in the EML/EMPGL devices provides electrical isolation between the DFB laser/amplifier and the modulator.

Abstract: A distributed feedback semiconductor laser (DFB laser) in which light feedback is performed by using a diffraction grating, and in which influence of external feedback noises can be decreased to suppress fluctuation of an optical output. The DFB laser comprises a diffraction grating structure portion which constitutes a resonator and which is divided into a plurality of regions along the longitudinal direction of the resonator, and one or more phase shift portions each disposed between adjacent regions of the diffraction grating structure portion, wherein total phase shift obtained by all of the phase shift portions has a quantity corresponding to &lgr;/n, where &lgr; is an oscillation wavelength, and n is an integer larger than 4 (n>4) and less than or equal to 16 (n≦16). The total phase shift may have a quantity corresponding to a value within a range between &lgr;/5 and &lgr;/8.

Abstract: A method for making of an optoelectronic device and the device therefor comprising confinement layers, waveguides and active layers, all of which comprise a superlattice of binary III-V compounds.

Abstract: There is provided a laser diode drive signal processor for driving a laser diode to be used to emit a laser beam for accessing an optical information recording medium with the laser beam. The processor has an alternating current side driving current supply circuit for supplying a first driving current according to a signal level of an alternating current component; a photo diode coupled to the laser diode for detecting a light amount of the laser beam; error signal generating circuit for generating an error signal based on the detected light amount of the laser beam and a reference signal; direct current side driving current supply circuit for supplying a second driving current according to a signal level of the error signal; and adding circuit for adding the first driving current from the alternating current side driving current supply circuit and the second driving current from the direct current side driving current supply circuit to generate a third driving current.

Abstract: A DFB laser in which a thickness of an active layer changes periodically and a greater part of current injected from external sides is selectively injected into the thick regions (projected regions) of the active layer. Therefore, the ratio of the gain coupling to the refractive index coupling can be further increased, and a threshold current can be lowered, and stability of single mode oscillation can also be improved.

Abstract: A semiconductor light emitting apparatus includes a semiconductor light emitting element which includes a stripe structure and an active layer made of an InGaN material, and emits first light without laser oscillation; an optical resonator; and a first wavelength selection unit which allows resonance, in the optical resonator, of second light having a selected wavelength included in the first light emitted by the semiconductor light emitting element. Alternatively, instead of the first wavelength selection unit, a second wavelength selection unit which allows output of only the above second light from the semiconductor light emitting apparatus may be provided. In this case, the semiconductor light emitting apparatus may further include an optical detector which detects intensity of the second light; and an output regularizing unit which drives the semiconductor light emitting element based on the detected intensity so as to regularize the intensity of the second light.

Abstract: An apparatus for monitoring and controlling the wavelength of laser radiation includes at a least one optical filter for receiving laser radiation and for transmitting and reflecting first and second filtered beams, respectively. The beams are filtered according to respective first and second spectral filter functions that cross at at least one crossing wavelength. A beam comparison element compares the first and second filtered beams and produces an error signal representative of the deviation of the wavelength of the laser radiation from a set-point wavelength. Varying the angle of incidence of the laser radiation upon at least one optical filter varies the spectral filter function of that filter for selecting or varying the operating wavelength of the laser. A laser wavelength controller can receive the error signal for stabilizing or tuning the wavelength of the laser radiation.

Abstract: A resonator mirror with a saturable absorber for a laser wavelength &lgr;L formed of a series of layers of a plurality of semiconductor layers on a substrate, wherein a Bragg reflector formed of a plurality of alternately arranged layers comprising a first material with an index of refraction nH and a second material with a lower index of refraction NL compared with the latter is grown on a surface of the substrate. It is characterized in that a threefold layer is grown on the Bragg reflector, wherein a single quantum layer is embedded within two layers outside an intensity minimum for the laser radiation &lgr;L and the threefold layer has a combined optical thickness of λ L 2 .

Abstract: A variation in optical output of a semiconductor luminous device outputting an optical signal to an optical fiber which is caused due to a variation in ambient temperature and an end of a life thereof capable of being compensated for without measuring the optical output. An output variation quantity H0(Ta) of the semiconductor luminous device due to the ambient temperature Ta is operated in a step S2. In a step S4, an output reduction quantity ST of the semiconductor luminous device obtaining by accumulating an output reduction ST thereof per unit time due to a deterioration of the device is provided. In a step S5, it is judged that a life of the device reaches an end when the output reduction ST exceeds a reference value ST0. When the former fails to exceed the latter, a variation quantity IH(Ta) of a drive current command value due to the ambient temperature Ta and a current reduction quantity IST(ST, dST) determined due to a deterioration of the device are operated in a step S6.

Abstract: An optically pumped semiconductor laser with the active region partitioned such that different wavelengths can be emitted simultaneously from each partitioned region. The material of the partitioning layers is selected to be transparent to the pump wavelength, an electronic barrier to carrier diffusion, and epitaxially compatible with subsequent layers of the laser structure.

Abstract: Disclosed herein is a semiconductor laser unit equipped with a semiconductor laser chip mounted within a package, a temperature sensing component fixed within the package, and an optical component fixed within the package. At least either the fixation of the temperature sensing component or the fixation of the optical component is performed with an inorganic adhesive.

Abstract: An optical semiconductor device is a buried hetero structure type, and includes a semi-insulating semiconductor block layer, a carrier trap layer, and a clad layer and a contact layer. Each of the clad layer and the contact layer is formed by selective growth. The carrier trap layer and the semi-insulating block layer have an etched mesa-structure.

Abstract: An S3-type laser diode includes a p-type cladding layer formed on an active layer such that an inclined surface region thereof has a carrier concentration level of 1×1018 cm−3 or more, wherein the p-type cladding layer has a thickness of 0.35 &mgr;m or more.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate, first and second active regions and a plurality of individual active regions. Each of an individual active region is positioned between the first and second active regions. A first oxide layer is positioned between the first mirror and the second mirror. A plurality of tunnel junctions are positioned between the first and second mirrors.

Abstract: The present invention provides a light source for an optical network. The light source includes a semiconductor optical gain element, having an axis of symmetry; and a mechanism for reflecting wavelengths that correspond to optical transmission channels of the optical network, the reflecting means optically coupled to the semiconductor optical gain element and intersecting the axis of symmetry. The light source of the present invention is a single multi-wavelength light source. It is designed to only emit wavelengths that specifically correspond to optical transmission channels. The mechanism of the light source suppresses possible mode hopping, thus maintaining the power stability of all channels. Since multiple wavelengths are provided in a single light source, the number of lasers required to service a network can be dramatically reduced, increasing efficiency and reducing the cost of equipment and time for maintenance as well.

Abstract: The high power laser diode comprise an active region and a trapping region separated by a passive region, all situated between a p-type confinement region and an n type confinement region such that the radiation field is attracted toward and spread into the trapping region assuring a reduced value for the confinement factor into the active region.