Abstract: A single-mode optical fiber for outputting high-power light wherein a diameter of a mode field at an output end of the optical fiber is made large to thereby lower a light power density. Material higher in thermal conductivity or melting temperature than material of the optical fiber is coated on the end face of the fiber. A thickness of the coating film is set to cause light wavelength to be phase-shifted by 1/4 of the wavelength to reduce reflection at the connecting end face. The same type of optical fiber is used as a party optical fiber to be connected therewith.

Abstract: Column wirings are divided into at least two groups of first column wirings and second column wirings. Image data corresponding to different rows in one frame are supplied to these groups of column wirings at the single timing. At the same timing, row signals are applied to the different wirings at e.g. j=1 and j=17. Rows and columns can be replaced by each other.

Abstract: In a semiconductor laser device comprising a plurality of semiconductor layers laminated in a vertical direction on a substrate to form a laser resonator, the laser resonator comprises a saturable absorbing region. A spot size of a light waveguide profile in the vertical direction is greater than 0.4 .mu.m. The laser resonator further comprises first and second reflecting films to provide a reflectivity greater than 50(%).

Abstract: A multipurpose optical sensor including an even number of optical fiber bundles, and optical systems for converting light guided through optical fiber bundles and leaving leading ends of optical fiber bundles into a substantially parallel light beam in a direction at right angles with the axes thereof, and converging substantially parallel light beam incident on axes from a direction at right angles therewith and guiding the thus converged light beam from leading ends into optical fiber bundles in the form of guide light.

Abstract: A semiconductor laser device includes an active region, a cladding region, and a carrier blocking layer of the same conductivity type as the cladding region disposed on tho same side of the active region as the cladding region. The carrier, blocking layer has a greater impurity concentration than the cladding region.

Abstract: This invention is a semiconductor device including a p-type InP substrate having a mesa stripe in which at least an active layer and an n-type cladding layer are formed, and a semiconductor layer so formed as to bury the side surfaces of the mesa stripe and having at least an n-type current blocking layer and a p-type current blocking layer, wherein the n-type current blocking layer contains approximately 8.times.10.sup.17 cm.sup.-3 or more of Se as an impurity and the n-type current blocking layer and the n-type cladding layer are not contacting each other.

Abstract: A VCSEL for emitting long wavelength light including a first mirror stack with mirror pairs in a GaAs/AlGaAs material system lattice matched to a GaTlP active region with an active structure sandwiched between a first cladding region adjacent the first mirror stack and a second cladding region, the active structure having a quantum well, and a second mirror stack lattice matched to the second cladding region and having mirror pairs in a GaAs/AlGaAs material system.

Abstract: Disclosed are optical couplers and optical coupling systems for coupling a source of non-coherent light to a light distribution harness, wherein the couplers are polygonal in cross section to increase light mixing. The couplers have inlet and outlet arms, and an intermediate bend region configured to achieve compactness and minimal light loss through the bend region. In one embodiment, the bend region is an integral part of the coupler, with the inlet arm having a different cross-sectional dimension from the outlet art in such manner that substantially all light directed from the inlet portion to the bend portion reaches the outlet arm portion, and light rays parallel to the inlet axis are reflected in the bend portion to be directed substantially parallel to the outlet axis. In a second embodiment, the bend region comprises a prism having a pair of parallel spaced surfaces, and inlet, outlet, and third surfaces that are non-parallel to the spaced surfaces.

Abstract: A new light-transmitting device using a SCIN glass core and a novel calcium sodium cladding has been developed. The very high index of refraction, radiation hardness, similar solubility for rare earths and similar melt and viscosity characteristics of core and cladding materials makes them attractive for several applications such as high-numerical-aperture optical fibers and specialty lenses. Optical fibers up to 60 m in length have been drawn, and several simple lenses have been designed, ground, and polished. Preliminary results on the ability to directly cast optical components of lead-indium phosphate glass are also discussed as well as the suitability of these glasses as a host medium for rare-earth ion lasers and amplifiers.

Abstract: An optical fiber having a core for propagating light, where the core includes first, second and third regions. The first, second and third regions are concentrically arranged with the second region around the first region and the third region around the second region. The third region includes a dopant for increasing the refractive index of the third region. The first region includes a first dopant for providing an amplification band and a second dopant for expanding the amplification band. The second region has an impurity concentration which is lower than the concentration of the dopant in the third region and is lower than the concentrations of the first and second dopants in the first region. Upon production of the fiber, the second region acts as a barrier to prevent diffusion of dopants. As a result, the amplification band can be effectively expanded. Various other arrangements of core and clad regions and dopants are provided.

Abstract: The invention relates to a III-V laser (amplifier) with an active region (4A) which encloses a small angle with the end faces (50, 51), is separated therefrom by a preferably current-blocking cladding layer (5) and has a tapering end (40) of which a first side face (42) coincides with a side face (42) of the remainder of the strip-shaped active region (4A), while a second side face (43) thereof encloses an acute angle with the perpendicular to the end faces (50, 51). Such a laser has an amplification ripple, which is undesirable. In a laser according to the invention, the second side face (43) of the tapering portion (40) encloses an angle with the perpendicular to the end face (50, 51) which lies between 0.degree. and 30.degree., preferably between 0.degree. and 10.degree., and which is preferably approximately 0.degree.. The laser according to the invention has a particularly low reflection, as a result of which said amplification ripple is absent or at least very small.

Abstract: An interferometric optical multiplexer 10 for use in optical communication systems and especially for use in optical communication systems employing fibre optical amplifiers is disclosed. The interferometric optical multiplexer has two input ports 12, 14, an output port 16 and an output monitoring port 18. The interaction of the input signals is monitored by a photodetector situated in the monitoring part 18. In conjunction with a feedback circuit 24 wavelength separation of signals input at pods 12, 14 is ensured.

Abstract: A vertical cavity surface emitting laser (VCSEL) device with an integral photodetector structure has improved intensity control characteristics. A laser optical source of the VCSEL emits light upward through a cavity formed in an upper electrode. A monitoring photodetector is formed below the laser optical source to receive light transmitted from the source downward. The intensity of the light transmitted downward from the optical source is proportional to the intensity of the light emitted upward through the cavity. Thus the detection signal provided by the photodetector sensing the downward transmitted light may be used for precise control of the driving voltage applied to the optical source. Because to the proportionality between the upward and downward emitted light, this control arrangement allows for improved control of emitted intensity of the VCSEL. An optical pickup apparatus adopting the improved VCSEL is also disclosed.

Abstract: A thermal optical switching cell has a channel of either gas or boilable liquid that crosses an optical waveguide at a forty-five degree angle. Two or more appropriately placed heaters use the water/steam/dry states of thermal ink jet technology to quickly insert, or extract, boilable liquid respectively into, or from, the channel. The boilable liquid has an index of refraction close to that of the guide. In the wet state, the channel contains the liquid and nearly all the light of the incoming guide traverses the liquid along the axis of the guide. In the dry state, the channel contains gas. Total internal reflection (TIR) occurs and light is directed at right angles away from the axis of the incoming channel. Adding a second waveguide, perpendicular to, and intersecting the first waveguide at the channel, forms a cross-bar switch. These liquid switching cells toggle between the wet and dry states. No power is required to hold the switch in the most recent state.

Abstract: A semiconductor light emitting device and a semiconductor laser device having an epitaxial growth layer composed of a III-V group nitride semiconductor. An AlN buffer layer, an n-type GaN intermediate layer, an n-type Al.sub.1-x Ga.sub.X N cladding layer, an In.sub.1-Y Ga.sub.Y N active layer and a p-type Al.sub.1-X Ga.sub.X N cladding layer, and a p-type GaN contact layer are successively formed on an n-type 6H--SiC substrate having a {0001} crystal growth plane. A p-side electrode is formed on the upper surface of the p-type GaN contact layer, and an n-side electrode is formed on the lower surface of the n-type 6H--SiC substrate, after which the n-type 6H--SiC substrate is cleaved along a {1120} plane to form a cavity facet.

Abstract: Several methods are used in novel ways with newly identified and viable parameters to decrease the peak transition energies of the pseudomorphic InGaAs/GaAs heterostructures. These techniques, taken separately or in combination, suffice to permit operation of light emitting devices at wavelengths of 1.3 .mu.m or greater of light-emitting electro-optic devices. These methods or techniques, by example, include: (1) utilizing new superlattice structures having high In concentrations in the active region, (2) utilizing strain compensation to increase the usable layer thickness for quantum wells with appropriately high In concentrations, (3) utilizing appropriately small amounts of nitrogen (N) in the pseudomorphic InGaAsN/GaAs laser structure, and (4) sue of nominal (111) oriented substrates to increase the usable layer thickness for quantum wells with appropriately high In concentrations.

Abstract: Several methods are used in novel ways with newly identified and viable parameters to decrease the peak transition energies of the pseudomorphic InGaAs/GaAs heterostructures. These techniques, taken separately or in combination, suffice to permit operation of light emitting devices at wavelengths of 1.3 .mu.m or greater of light-emitting electro-optic devices. These methods or techniques, by example, include: (1) utilizing new superlattice structures having high In concentrations in the active region, (2) utilizing strain compensation to increase the usable layer thickness for quantum wells with appropriately high In concentrations, (3) utilizing appropriately small amounts of nitrogen (N) in the pseudomorphic InGaAsN/GaAs laser structure, and (4) sue of nominal (111) oriented substrates to increase the usable layer thickness for quantum wells with appropriately high In concentrations.

Abstract: A printed circuit board with a face plate having a connector support located behind it and being movable for access to the connector support. The connector support has a connector mounting for connecting two fiber connectors, the geometry being such that with the face plate removed, the rearwardly directed connector and accompanying fiber is accessible together with the forwardly directed fiber and connector for cleaning purposes without removal of the circuit board from operational position within a shelf.

Abstract: The present invention concerns an optical fiber cable containing a plurality of optical fibers split up into modules, each module being covered with a supporting sheath in contact with the outer optical fibers of the module so as to hold the optical fibers contained in said module tightly so that they are mechanically coupled to one another, the entire set of modules being disposed inside a covering made of an insulating material, which covering is in contact with the outer modules of the set of modules so as to form a compact assembly comprising all of the modules;wherein each optical fiber has a cut-off wavelength of not more than 1,350 nm, and, at a wavelength in the vicinity of 1,550 nm, has a mode field diameter lying in the range 7 .mu.m to 9 .mu.m, and wherein each optical fiber is provided with a substantially hermetic coating on its optical cladding.

Abstract: A method of generating a Bragg reflective grating in a photosensitive optical waveguide using a fringe pattern of electromagnetic radiation additionally employs a further beam of radiation to promote differential heating of the fibre in the region where the grating is being generated. The differential heating produces differential photo-sensitivity of the fibre so that the resulting grating, though it has a constant physical pitch, has an effective optical pitch that is a function of position along the length of the grating.