摘要:
A semiconductor laser device includes: an electrically insulating film, on the top face of a laser chip; and a metal film, on the electrically insulating film. The electrically insulating film and/or the metal film has, in plan, a polygonal shave with five or more apexes, each of the apexes having an interior angle less than 180 degrees. Stress due to a change of temperature during operation is reduced, resulting in a semiconductor laser device having a longer life and higher reliability.
摘要:
A long wavelength transmitter OEIC includes a transverse direction current injection type semiconductor laser and a high electron mobility transistor which are integrated on a semi-insulating substrate. The semiconductor laser includes at least an AlGaInAs lower cladding layer, a quantum well active layer and a high resistivity AlGaInAs upper cladding layer successively grown on the semi-insulating substrate, disordered regions formed in the quantum well active layer by diffusions of p type and n type dopants, and an active region sandwiched by the disordered regions. The transistor includes an operating layer and a carrier supplying layer both including AlGaInAs series material and formed on the high resistivity AlGaInAs upper cladding layer. This transistor uses the upper cladding layer as a leakage current preventing layer. This structure can be formed by only one epitaxial growth, resulting in low cost. In addition, since the above layers are successively grown on a flat substrate, photolithography processes for forming a gate of HEMT are performed on a flat surface, so that a fine gate pattern can be formed with high precision. As a result, a transmitter OEIC performing high speed modulation are produced.
摘要:
A semiconductor laser device provided with a broad light waveguide through which a higher order transverse oscillation modes can propagate, includes at least one of laser facet having a high reflectance region having a width of about 1/5 to 1/2 of the width of the light waveguide located at a central portion thereof and a low reflectance region having a lower reflectance than the high reflectance region located at both sides of the high reflectance region whereby higher order modes of oscillation can be suppressed.
摘要:
A laser device comprises a laser medium, a semiconductor light-emitting element for exciting the laser medium, a reflecting surface surrounding the outer periphery of the laser medium along its optical axis, and an opening provided in a part of the reflecting surface for causing light from the semiconductor light-emitting element to be incident upon the laser medium. The laser device is improved further by providing a polarizing plate and a light guide between the light-emitting element and the laser medium and by deviating the optical axis of excitation light from the central axis of the laser medium.
摘要:
A method for producing a semiconductor laser including successively growing at least two semiconductor layers simultaneously on a substrate, the finally grown layer not containing aluminum and the layer grown immediately before the finally grown layer containing aluminum, etching a stripe groove through the finally grown layer to expose part of the semiconductor layer containing aluminum, growing a second semiconductor layer not including aluminum on the finally grown layer and the exposed surface of the semiconductor layer containing aluminum, and growing a semiconductor layer including aluminum on the second semiconductor layer not containing aluminum.
摘要:
A pulsation laser includes an n-type AlGaAs cladding layer on an n-type GaAs substrate, three quantum well active layers having central increased thickness regions and disposed on the cladding layer, and a p-type AlGaAs cladding layer disposed on the quantum well active layer. The increased thickness region of the active layer is not more than one-quarter of the length of the resonator of the laser.
摘要:
A semiconductor laser device includes, on a first conductivity type GaAs substrate, successively, a first conductivity type GaAs buffer layer, a first conductivity type Al.sub.s Ga.sub.1-s As (0
摘要:
A semiconductor wafer includes a notch or a hole used in preparing an orientation flat on the wafer. The notch in the wafer includes a side that is perpendicular to the surfaces of the wafer and aligned along a cleavage plane of the wafer for forming the orientation flat by cleaving. A hole in a wafer preferably includes an axis aligned along the cleaving plane. A sharp, non-rounded cleavage is formed by preparing the notch or hole after the completion of any etching processes or other steps that may round the edges of the flat. The sharp edges aid in achieving a precision alignment using the orientation flat.
摘要:
In a method of fabricating an integrated semiconductor light modulator and laser device, a semiconductor layer having first and second regions of different crystal compositions is produced on each chip region of a semiconductor wafer by a selective crystal growth using, as a mask, a dielectric film having a prescribed pattern. Thereafter, a semiconductor laser and a light modulator that modulates laser light emitted from the semiconductor layer are produced in a first semiconductor region and a second semiconductor region, respectively, of each chip region. In this method, the shape of the dielectric mask pattern and the shape of the opening of the mask pattern on each chip region is symmetrical with the dielectric mask pattern and opening of an adjacent chip region along the optical waveguide direction of the semiconductor laser. The semiconductor layer is grown on the wafer so that the first and second semiconductor regions of different crystal compositions on each chip region are in contact with semiconductor regions having the same crystal composition of an adjacent chip region. As the result, at opposite edges of the chip region in the optical waveguide direction, the crystal compositions of the first and second semiconductor regions are the same.
摘要:
A semiconductor laser device has a thyristor current confinement structure at both sides of an active region. A p-n junction in the current confinement structure is forward biased during laser operation and is short-circuited by a metal layer or a low resistance material layer. Therefore, injection of holes from the p layer into the n layer of the short-circuited junction during laser operation is suppressed whereby the thyristor current confinement structure is not likely to be turned on. In addition, the current flowing through the blocking layer is decreased. As a result, current blocking is significantly improved, preventing a reduction in the laser output power and a reduction in the linearity of the light output versus current characteristic of the laser.