Abstract: A semiconductor laser module in which an exciting laser beam output is always allowed to be in a multi-mode and the variation of optical output does not occur. In the semiconductor laser module, a semiconductor laser device, light coupling means and an optical fiber are disposed, and further, a light feedback (return) portion where a laser beam of a specific wavelength is reflected is formed, and the reflection spectrum at the light feedback portion has a shape similar to a rectangular one.

Abstract: The semiconductor laser device has the lower clad layer, active layer, upper clad layer, contact layer, the insulating film, and the positive electrode sequentially formed on the semiconductor substrate. The upper clad layer, the contact layer and the insulating film form the ridge. The positive electrode covers the upper and side faces of the ridge. The thickness of the positive electrode on the upper and side faces of the ridge is preferably substantially the same and it is not less than 150 nm.

Abstract: A semiconductor laser diode including: a resonator structure including a first facet having a reflection film and a second facet having an antireflection film; and an active region including a linear section a uniform width extending from the first facet along a direction of the resonator and a flared section extending from the linear section toward the second facet, the flared section having a tapered width increasing toward the second facet, wherein the relation of d<&lgr;0/{2·(2·n0·&Dgr;n)0.5} holds. The semiconductor laser diode which emits in a stabled fundamental mode can be realized by satisfying the above relation for increasing the effect for suppressing the spatial hole-burning phenomenon.

Abstract: A GaAs based semiconductor laser has a combination of cladding layers including a ridge structure part, and a remaining part which overlays the active layers of the laser, and an etch stop layer sandwiched between the ridge structure part and the remaining part. The remaining part preferably overlies the entire surface of laser active layers and has a thickness “D” which satisfies 1.1×W>D≧0.5×W wherein W is the width of a spot size having a strength of {fraction (1/e2)} as measured at the laser front facet in a direction perpendicular to the active layers, wherein “e” is the base of the natural logarithm. The semiconductor laser solves the kink phenomenon to obtain an excellent linear relationship between the optical output power and the injected current.

Abstract: A passivation layer suppresses an output end face of a semiconductor laser having a band of an oscillation wavelength of 980 nm from being degraded and contributes to securance of the long-term reliability of the semiconductor laser. In a passivation layer, for a semiconductor laser, having a two-layered structure and constituted by a first thin film directly formed on the output end face of the semiconductor laser and a second thin film formed on a surface of the first thin film, the thickness of the first thin film is set such that, in a calculation expression for calculating the reflectance of the passivation layer by a matrix method, a differential coefficient obtained when the calculation expression is differentiated by the film thickness of the first thin film is zero.

Abstract: A exemplary method of fabricating a semiconductor laser device includes forming an electrode on each of a top surface and a bottom surface of a laminated structure comprised of semiconductor materials, then cleaving the laminated structure to form facets of a cavity, and next epitaxially growing a compound semiconductor on the facets of the cavity. Works involved in the cleavage and the epitaxial crystal growth are performed in a low oxygen and moisture concentration atmosphere, so that the occurrence of COD is suppressed in the fabricated semiconductor laser device.

Abstract: The semiconductor laser element comprises, from bottom to top, the p-AlxGa1−xAs upper clad layer, p-AlyGa1−yAs resistance control layer, and p-GaAs cap layer (where x>y>0.2). A portion of only the resistance control layer and cap layer is selectively etched. The etchant used for this etching is a mixture of organic acid and hydrogen peroxide based mixture, has such a composition such that the ratio of dissolution rate of the upper clad layer to the cap layer is between 10 and 20, and pH is between 7.4 and 7.6.

Abstract: In a semiconductor laser device comprising a semiconductor laser main body having an active layer formed between a pair of cladding layers, and a non-absorbing layer of InGaP formed on the facets of the semiconductor laser main body and having a band gap greater than the band gap of the active layer,a diffusion blocking layer of, for example, Si, SiN or Ge is formed on the surface of the non-absorbing layer, and a di-electric protective layer of, for example, AlO.sub.x, SiO.sub.x, SiN.sub.x or MgO.sub.x for regulating reflectance at the facets and protecting the non-absorbing layer is formed on the diffusion blocking layer.

Abstract: A surface emission semiconductor laser device has a semiconductor laminate mirror constituted of a plurality of pairs of InGaAS/InAlP films epitaxially grown on a GaAs or InGaAs substrate and a laser element bonded to the laminate mirror. The InAlP films of the laminate mirror are lattice-matched or not lattice-matched due to the amount of Al in the InAlP films. The laminate mirror has a high relative refractive index between the InGaAs and InAlP films and thus has a high reflectance to thereby improve the emission efficiency of the surface emission laser device.

Abstract: A semiconductor laser has a multiple-quantum well (MQW) structure overlying a first III-V compound semiconductor. The MQW includes a plurality of layer combinations including a strained well layer and a strained barrier layer, which are formed in a cyclic order. An ultra-thin intermediate film made of the first III-V compound semiconductor and having a thickness corresponding to from monoatomic layer to ten atomic layer is interposed between each strained well layer and each strained barrier layer. The intermediate film functions for preventing formation of mixed crystal formed between the well layer and the barrier layer, thereby improving current density threshold and other characteristics of the semiconductor laser.

Abstract: A semiconductor laser device has a GaAs substrate (11), a single- or multiple-quantum well (QW) structure including at least one InGaAs strained QW active layer (16), a pair of GaAsP or In.sub.z Ga.sub.1-z AsP barrier layers (15,17) (z.ltoreq.0.3) interposing therebetween the QW structure, and a pair of AlGaAs cladding layers (13, 19) sandwiching the pair of barrier layers (15,17) and the QW structure as a whole. The semiconductor laser prevents a catastrophic optical damage (COD) caused by recombination current due to the presence of aluminum and exhibits a high optical output power.

Abstract: A HBT comprises a collector layer, a base layer and an emitter layer overlying a semi-insulating GaAs substrate. The base layer is composed of graded-composition GaAs.sub.1-x P.sub.x wherein x is 0 at the interface between the base layer and the collector layer, linearly increases as viewed toward the emitter layer and is 0.15 at the interface between the base layer and the emitter layer. The graded-composition of GaAs base layer provides a high carbon dosage, a high current gain and a high cut-off frequency without rise in the offset voltage.

Abstract: A semiconductor laser is produced by forming a laser activation section and a light emitting section having an InGaAsP layer as a quantum well on a GaAs substrate according to metal organic chemical vapor deposition by using a selective area growth mask, in such a manner that the laser activation section and the light emitting section have different film thicknesses. The laser activation section includes a laser activation layer whose oscillation wavelength is set to 0.8 to 1.1 .mu.m, and the light emitting section includes an optical waveguide layer having a broader forbidden band than the laser activation layer.

Abstract: In an optoelectronic integrated device having an optical element section in the wavelength region of 1.33 to 1.55 .mu.m and an electronic element section such as an HEMT integrated in a monolithic form on a GaAs substrate, the optical element section includes light receiving elements or light emitting elements, and an optical absorption layer of the light receiving element or a semiconductor layer forming an active layer of the light emitting element is formed of GaAsN-series compound semiconductor which is lattice-matching with the GaAs substrate, particularly, one of GaAsN, InGaAsN, InGaAsPN, GaAlAsN, InGalAsN, AlGaAsPN and InGaAlAsPN.

Abstract: A snow vehicle of the saddle-riding type utilizes essentially the same upper structure as a motorcycle but mounts a ski on the front fork for steering and an engine-driven endless belt track assembly for powering the device. The endless belt track assembly is arranged for mounting on a rear arm structure in order to maintain surface contact between the endless belt and the snow and thereby improve the operating efficiency of the vehicle. The arm may be pivotally mounted or integral with a rear fork pivotally mounted to the vehicle. An improved endless belt construction is described in which the belt is strengthened by core members and the driving cogs of particular configuration and disposed at prescribed locations with respect to the propelling lugs in order to maintain surface contact between the belt edge and the snow surface during cornering. Also disclosed are various forms of cover structures for the track assembly that prevent the scattering of snow from the belt onto the rider or vehicle parts.

Abstract: There is provided a semiconductor laser device that can be driven for a high-output power level without degradation in the quality of the device. It comprises a double heterostructure including an active layer (5, 25) and an electrode layer (9, 29) arranged on a semiconductor substrate (1, 21) having a current injection region extending through the electrode layer (9, 29) and the active layer (5, 25), a structural scheme being provided either in a region located above the active layer (5, 25) or in a region covering an resonator of the active layer (5, 25) in order to reduce the injection current level of the device. With such an arrangement, the energy output level of the semiconductor laser device is remarkably enhanced and its reliability is greatly improved, because it can be driven for a high-output power level without degradation in the quality of the device.