摘要:
A semiconductor laser device is provided which is constituted by semiconductor materials so as to emit laser light from a cavity end facet, the laser light being excited in a waveguide within an active layer sandwiched between a pair of cladding layers, wherein a window layer made of a semiconductor material having a band gap greater than that of the active layer is formed on the cavity end facet from which the laser light is emitted, so as to have a thickness sufficient to prevent local generation of crystal defects by lattice mismatching between the semiconductor material of the window layer and the semiconductor materials at the cavity end facet. There is also provided a method for producing such a semiconductor laser device with high efficiency.
摘要:
A semiconductor light emitting device which allows part of an active layer to generate light by supplying current to the part of the active layer is disclosed. The semiconductor light emitting device includes: a semiconductor substrate having upper and lower surfaces, the upper surface having a stepped portion, the stepped portion dividing the upper surface into at least a first area and a second area; a current confining layer, formed on the upper surface of the substrate, the current confining layer being discontinuous at the stepped portion, the current flowing through an area between the first area and the second area of the substrate; a multilayer structure formed on the current confining layer, the multilayer structure including the active layer; a first electrode which covers only part of an upper surface of the multilayer structure; and a second electrode formed over the lower surface of the substrate. In the semiconductor light emitting device, the light generated from part of the active layer is extracted to the outside through a portion of the upper surface of the multilayer structure which is not covered with the first electrode.
摘要:
A surface electrode on a surface of a LED has a pad, and further, at least first-order branches linearly extending from the pad, second-order branches diverged and linearly extending from the first-order branches, and third-order branches diverged and linearly extending from the second-order branches. The pad out of the surface electrode is not in electrical contact with a underlying semiconductor layer, whereas the surface electrode and the semiconductor layer are in electrical contact with each other at ends of the highest-order branches. Also, the semiconductor layer is provided along a pattern of the surface electrode in a mesa shape. Thus, ineffective light emission underneath the surface electrode is relatively reduced so that external quantum efficiency can be improved, and moreover even shorter-wavelength light can be allowed to go out at high efficiency by omitting a current diffusion layer.
摘要:
A method for producing a semiconductor laser device includes the steps of: forming window layers on either one of a top surface of an internal structure or a reverse surface of a substrate and on light-emitting end facets of the internal structure; forming a reflection film on the light-emitting end facets; removing the window layer formed on either one of the top surface or the reverse surface by using an etchant which hardly etches the reflection film; and forming electrodes on the surface from which the window layer is removed by etching and on the other surface. Another method for producing a semiconductor laser device includes the steps of: forming window layers on light-emitting end facets of the bars; inserting the bars into an apparatus having openings for forming electrodes and a supporting portion for preventing a positional shift between the bars and the openings, and forming the electrodes on the top surfaces and the reverse surfaces of the bars; and cutting the bars into the chips.
摘要:
A method for producing a semiconductor laser device includes the steps of: forming window layers on either one of a top surface of an internal structure or a reverse surface of a substrate and on light-emitting end facets of the internal structure; forming a reflection film on the light-emitting end facets; removing the window layer formed on either one of the top surface or the reverse surface by using an etchant which hardly etches the reflection film; and forming electrodes on the surface from which the window layer is removed by etching and on the other surface. Another method for producing a semiconductor laser device includes the steps of: forming window layers on light-emitting end facets of the bars; inserting the bars into an apparatus having openings for forming electrodes and a supporting portion for preventing a positional shift between the bars and the openings, and forming the electrodes on the top surfaces and the reverse surfaces of the bars; and cutting the bars into the chips.
摘要:
A light wavelength converter which includes a light source for emitting fundamental waves having a desired wavelength, a first loop-shaped optical waveguide for converting the fundemental waves into harmonics, and a second optical waveguide for receiving the light from the source, wherein the two waveguides are coupled by an optical directional coupler.
摘要:
A laser beam oscillating apparatus which includes a plurality of semiconductor laser beam oscillators (21, 22, 23) oscillating laser beams of a different wavelength from each other, an optical waveguide (12) formed on a substrate (11) so that the oscillated laser beams propagate therein and are then emitted in the same direction from the output end thereof and an optical coupler (13) to introduce the laser beams into the optical waveguide, thus allowing simultaneous introduction of these semiconductor laser beams of different wavelengths into the optical waveguide and simultaneous output of them in the same direction from the output end thereof.
摘要:
A light wavelength converter which includes a laser beam source for radiating fundamental waves, a first optical waveguide formed on a substrate so as to convert the fundamental waves into harmonics which are radiated through the substrate, a grating coupler provided on the substrate so as to receive the harmonics propagated through the substrate, and a second optical waveguide formed on the substrate, the second optical guide being connected to the grating coupler so as to radiate the harmonics outside.
摘要:
The present invention is concerning to an image management system that communicates with a first communication terminal via a communication network, the image management system comprising: an image storage unit configured to store image data; a receiving unit configured to receive, from the first communication terminal, link information that includes image identification information for identifying the image data and includes predetermined-area information that indicates a predetermined area in the image data; and a transmitting unit configured to transmit, to the first communication terminal, the image data that is indicated by the image identification information included in the link information received by the receiving unit and the predetermined-area information included in the link information.
摘要:
Disclosed is a battery system wherein safety of a lithium secondary battery can be enhanced by efficiently deactivating (inactivating) lithium metal deposited on a negative electrode of the lithium secondary battery. Also disclosed is an automobile. Specifically disclosed is a battery system comprising a lithium ion secondary battery and a temperature control unit for controlling the temperature of the lithium ion secondary battery. The temperature control unit performs such a control that the temperature T of the lithium ion secondary battery is maintained within the following range: 55° C.