Abstract: An active region of a VCSEL at one (i.e., n doped) end having an expanded effectively undoped region, and another (i.e., p doped) end having a significantly doped region up to or even including a portion of the active region. A previous way had heavy doping of the n and p doped regions up to the active region, at least close to it or even partially into it.

Abstract: Described embodiments provide a method and apparatus for transmission of optical communications. An embodiment provides an optical transmitter which includes a control circuit to enhance the stability of output power levels, a modulator circuit with precise impedance matching for high frequency performance, and an optical coupling mechanism that relaxes the alignment tolerances between the laser and the fiber and decreases the sensitivity of the gain medium to feedback from devices coupled to the fiber. These features allow the transmitter to deliver an optical output beam which can be modulated over a wide range of frequencies, duty cycles and amplitudes with very precise definition of the rising and falling edges of the waveform. In combination these features result in an optical transmitter that may be fabricated with relatively low cost and a reduced form factor when compared with prior art optical transmitters.

Abstract: A laser for delivering laser radiation at a selected one of a plurality of equally-spaced frequencies extending over a frequency range includes a laser resonator defined by two end mirrors. The resonator includes a surface-emitting semiconductor multilayer gain-structure in optical contact with one of the mirrors. A third mirror located in the laser resonator forms an etalon with that mirror. The third mirror is movable for adjusting a peak transmission frequency of the etalon to align with the selected frequency. The resonator end mirrors are spaced apart by an optical distance selected such that the frequency and frequency-spacing of possible longitudinal lasing modes of the resonator correspond with the plurality of equally-spaced frequencies. When the peak transmission frequency of the etalon is aligned with the selected frequency the laser resonator delivers radiation in a single longitudinal mode at the selected frequency.

Abstract: Multiwavelength laser source transmitting a luminous flux including as many amplifier wave-guides as potential transmission wavelengths, a collimation optic system for collimating the beams transmitted by the wave-guides, a network and a retroreflector making up the network, a dispersive retroreflecting device that defines with each wave-guide, an external resonating cavity, whereas each wave-guide has an inner face and an outer face with respect to its associated cavity. A Fabry-Perot interferometer with reduced fine adjustment is placed in the cavity between the collimation optic system and the network, whereby the interferometer is tilted with respect to the axis of the cavity and forms a little selective filter, whose variation law of the wavelength transmitted in relation to the angle of incidence is identical with that of the dispersive retroreflecting device.

Abstract: An optical device structure includes a first substrate structure and a second substrate structure. The first substrate structure includes a first substrate, at least an active region formed on the first substrate, and at least a first electric connector portion provided corresponding to the active region for injecting a current into or applying a voltage to the active region. The second substrate structure includes a second substrate, and at least a second electric connector portion formed on the second substrate corresponding to the first electric connector portion. The first and second substrates are bonded to each other using an anisotropic electrically-conductive adhesive containing electrically-conductive particles and having an elctrically-conductive characteristic only in a direction perpendicular to the first and second substrates, such that the corresponding first and second electric connector portions on the first and second substrates are electrically connected to each other.

Abstract: The present invention aims at providing a light source for a semiconductor laser beam scanner having high resolution in scanning and a high degree of mounting freedom, and suitable for emitting a laser beam from the surface. Therefore, a surface emission type semiconductor laser includes at least a first mirror 102, an active layer 103, a current narrowing layer 113, a contact layer 106, and a second mirror 111, which are formed on a semiconductor substrate 101; wherein the current narrowing layer 113 is made of a stripe AlAs layer 105, and an Al oxide layer 108 formed to surround the AlAs layer 105; the region of the contact layer 106, which overlaps the Al oxide layer, is formed in a comb shape 109, and independent contact electrodes 110 are respectively formed on the upper surfaces of the teeth of the comb shape 109 of the contact layer.

Abstract: A vertical cavity apparatus includes a first mirror, a substrate and a second mirror coupled to the substrate. At least a first and a second active region are each positioned between the first and second mirrors. At least a first oxide layer is positioned between the first and second mirrors. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a fused mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. A first etched layer is positioned between the first and second mirrors. A first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a lattice relaxed mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a dielectric mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes a first mirror, a substrate and a second mirror coupled to the substrate. At least a first and a second active region are each positioned between the first and second mirrors. At least a first ion implantation layer is positioned between the first and second mirrors. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A modulated laser device comprising two or more vertically stacked asymmetric waveguides is provided. The laser device comprises a first waveguide having a gain region formed therein for amplifying at least a first mode of light, and a second waveguide vertically coupled to the first waveguide and having a modulator formed therein for modulating a second mode of light having an effective index of refraction different from the first mode. Light propagating in the first waveguide is transferred into the second waveguide via a lateral taper in the first waveguide. The laser device may further comprise a third waveguide positioned between the first and second waveguide for providing isolation between the gain region and modulator. Distributed bragg reflector (DBR) and distributed feedback (DFB) laser designs may be employed in the device.

Abstract: An A1-free VCSEL is grown by MOCVD procedure by growing GaInP/GaAs as a conventional distributed Bragg reflector (DBR) 36 or less periods are then formed as the active layer. The DBRs are composed of repeating layers of a 69 nm period of GaAs and a 76 nm period of InGaP to form a superlattice as quarter wave thickness stacks. After the lower layer of n-type DBR is deposited by MOCVD, a lift-off procedure opens up windows in an evaporated layer of SiO2. The active region and upper p-type DBR is then deposited by MOCVD.

Abstract: A technique for driving a laser diode on the basis of automatic power control (APC) is disclosed. The technique uses, for the bottom level feedback control, a constant reference voltage instead of a variable intermediate signal generated in the peak level feed back control. The constant reference voltage may be either a reference voltage for the peak level control or a separately generated voltage. A technique for setting the extinction ratio to 1/n is also disclosed.

Abstract: An active region of a VCSEL at one (i.e., n doped) end having an expanded effectively undoped region, and another (i.e., p doped) end having a significantly doped region up to or even including a portion of the active region. A previous way had heavy doping of the n and p doped regions up to the active region, at least close to it or even partially into it.

Abstract: An insulating member (4) of an amorphous structure partially opened to expose a substrate (1; 1, 2, 3) is formed on the substrate. At least a compound semiconductor (5, 51, 52) containing at least nitrogen as a constituent element is deposited on the insulating member (4) and the substrate (40) exposed by the opening thereby to form a semiconductor material (1, 5, 51, 52). A semiconductor material (6, 7) configured of the first semiconductor material or configured of the first semiconductor material and another semiconductor material grown on the first semiconductor material is processed thereby to form a semiconductor device.

Abstract: An integrated surface emitting laser and modulator device is disclosed that includes a detector for monitoring the optical power output of the laser and another detector for monitoring an extinction ratio of the modulator. A cleave physically and electrically separates the laser from the modulator device. The device has a collimating lens disposed on a top surface.

Abstract: To more precisely output signals of optical recording media, a semiconductor laser element is mounted in a concave portion on the surface of a semiconductor substrate so that the optical axis of signal detecting light emitted from the semiconductor laser element is substantially parallel to the surface of the semiconductor substrate, and the light emitted from the semiconductor laser element is reflected at the side surface of the concave portion that is opposed to the signal detecting light emitting side of the semiconductor laser element in a direction substantially perpendicular to the surface of the semiconductor substrate. A light receiving portion for signal detection is provided in an area outside the concave portion on the surface of the semiconductor substrate where the semiconductor laser element is mounted.

Abstract: A semiconductor laser device (100) comprises a first semiconductor laser element (31) and a second semiconductor laser element (32) of different wavelengths, which are mounted on a heat sink block (2) directly or through a sub-mount provided on the heat sink block. The optical axes (A, B) of the semiconductor laser elements are substantially parallel to each other. The first and second semiconductor laser elements (31, 32) are mounted on the heat sink block (2) in such a manner that a relationship of 0≦L≦d1+d2≦160 &mgr;m is satisfied, where d1 is a distance between the optical axis (A) of the first semiconductor laser element (31) and the center axis (O) of a condenser lens (71) arranged in front of the semiconductor laser device (i.e.