Abstract: A mounting of semiconductor laser chip on a heat sink or metal mount is improved so as to enable high accuracy of position and direction. A heat sink or metal mount, on which a semiconductor laser chip is mounted, comprises two parts, namely a main mount or larger portion and a sub-mount or smaller portion. The semiconductor laser chip is soldered by a solder layer on the sub-mount utilizing a microscope so as to assure an accurate position and an accurate direction with respect to the sub-mount. Then, the sub-mount is soldered on the main mount by a solder layer with an accurate relation both in position and direction by engaging a linear ridge as a first engaging means provided on the upper face of the main mount with a straight groove and a rear end face as a second engaging means. As a result of the above-mentioned structure, accurate position and direction of the semiconductor laser chip with respect to the mount is easily obtainable with a high yield.

Abstract: The invention provides a polyolefin-based rubber composition capable of giving a vulcanizate having excellent flame retardancy along with high mechanical strengths. The composition comprises: (A) 100 parts by weight of a polyolefin-based synthetic rubber, e.g. EPDM rubber; (B) 1 to 100 parts by weight of an organopolysiloxane; (C) 1 to 100 parts by weight of a bromine-containing flame retardant agent and/or red phosphorus; (D) 5 to 200 parts by weight of aluminum hydroxide and/or magnesium hydroxide; and (E) 0.5 to 20 parts by weight of zinc carbonate and/or manganese carbonate.

Abstract: A mounting of semiconductor laser chip on a heat sink or metal mount is improved so as to enable high accuracy of position and direction. A heat sink or metal mount, on which a semiconductor laser chip is mounted, comprises two parts, namely a main mount or larger portion and a sub-mount or smaller portion. The semiconductor laser chip is soldered by a solder layer on the sub-mount utilizing a microscope so as to assure an accurate position and an accurate direction with respect to the sub-mount. Then, the sub-mount is soldered on the main mount by a solder layer with an accurate relation both in position and direction by engaging a linear ridge as a first engaging means provided on the upper face of the main mount with a straight groove and a rear end face as a second engaging means, or by engaging a square recess as a first engaging means and the square bottom of the sub-mount as a second engaging means with each other.

Abstract: The invention provides a highly flame-retardant polyolefin-based rubber composition free from the problem of the formation of toxic or corrosive gases and a large volume of smoke by burning of conventional flame-retardant rubber compositions impregnated with a large amount of a halogen-containing flame retardant agent. The inventive rubber composition comprises (a) a synthetic rubber of polyolefin type, (b) an organopolysiloxane resin which is preferably formed of monofunctional siloxane units and tetrafunctional siloxane units in a molar ratio of 0.6/1.0 to 2.0/1.0, (c) red phosphorus and (d) aluminum hydroxide or magnesium hydroxide in a specified proportion.

Abstract: On a semiconductor laser substrate, a groove of tapered width is formed, and at least one crystal layer is formed on the substrate. The crystal layer is usable as a waveguide with two light input ends l.sub.1 and l.sub.2 and one light output end l.sub.3 as shown in FIG. 4(C).

Abstract: In a semiconductor laser of terraced substrate type, comprising on a terraced substrate (11) of n-GaAs substrate, a first clad layer (12) of n-GaAlAs, an active layer (13) of non-doped GaAlAs, a second clad layer (14) of p-GaAlAs and a current limiting layer (15) of n-GaAs, and further thereon a thick overriding layer (19) of n-GaAlAs with strip shaped opening (191), are epitaxially formed, and a current injection layer (16) is formed by Zn diffusion through the opening (191) in a manner one corner (161) of the injection front penetrate the current limiting layer (15) and reaches the second clad layer (14). By means of thick overriding layer (19), shortcircuiting between the active layer (13) and a p-side electrode (7) is prevented.

Abstract: A stem for a semiconductor laser device of a terraced substrate structure which has a tilted active layer against flat parts of the substrate, the stem comprises a base plate and a heat sink block, a flat face of the heat sink block for bonding the semiconductor laser device thereonto is tilted with respect to a base face of the base plate; this stem has features that the polarization direction of the lased light from the semiconductor laser device can be set to be parallel to (or perpendicular to) the base face of the base plate, and therefore it becomes much easier to make adjustments related with the polarization direction of the lased light.

Abstract: A terrace-substrate laser is improved by forming a stripe-shaped impurity diffused current-injection region (27) from the cap layer (25) at least so as to reach the oblique lasing region (231) of the active layer (23), so that the corner part of the current injection region (27) touches the lasing region (231); thereby current injection efficiency to the lasing region is highly improved and the injected current is effectively limited in the oblique lasing region even when a large current is injected, and furthermore, a threshold current can be greatly reduced. This laser can perform a stable fundamental transverse mode oscillation even at a large current operation.

Abstract: A very narrow current injection region (16") is made by means of terrace-shaping of the surface of the current limiting layer (13) forming a step thereon, the current limiting layer being on the epitaxially grown double hetero structure layers (10, 11 and 12) including the active layer (11). By so terrace-shaping, when Zn as a p-type impurity to form the current injection region (16) is diffused from the surface of the current limiting layer (13), the diffused region is formed to have a deeper part (16") and a shallower part (16'), and the deeper part (16") can be made very narrow by selecting the position of the stripe-shaped diffused region with respect to the step (14).

Abstract: In a terraced substrate type semiconductor laser comprising a semiconductor substrate (11) having a step (T) on its principal face, an active layer (13) with an oblique central region (131), defined between two bendings, as stripe-shaped lasing region near the foot of the step part (T) of the substrate (11), and a clad layer (14) formed on the active layer (13),The device is characterized by comprising a current injection region (22) which is formed by diffusing an impurity, in a manner that a diffusion front corner (221) penetrate the clad layer (14) and contacts the oblique lasing region (131) thereby to form the current injection path (221) very narrow and closely to the central part of the stripe-shaped lasing region (13), thereby effectively confining the injected current to the lasing region (131) and hence attaining very low threshold current and very high external differential quantum efficiency.

Abstract: A terraced semiconductor laser comprising semiconductor layers (10, 11, 12) including an active layer (11) formed on a terraced semiconductor substrate (9) in a manner to have an inclined part (111) ranging from the position above said step to the part shifted to the side of said thinner part,an overriding layer (13) having the opposite conductivity type to that of the uppermost layer (12) of said semiconductor layers (10, 11, 12) and formed on said uppermost layer (12),characterized by further comprising:a last layer (14) having the same conductivity type to that of the overriding layer (13) formed on the latter layer (13),said last layer (14) having a stripe-shaped through-opening (141) at the position which is a shifted position from the part immediately above said inclined part 111, thereby exposing a surface of said overriding layer (13) at the bottom of the through-opening (141),a conduction region (15) formed at least on the bottom and side faces of said stripe-shaped opening, in a manner to reach and

Abstract: In a laser comprising a GaAs substrate, an active layer of GaAlAs put between a first and a second clad layers, a buffer layer is disposed between said first clad layer and said substrate, and thermal expansion coefficient of the buffer layer is selected smaller than that of said active layer; thereby an internal stress of the active layer is released and lifetime of the laser is very much prolonged.

Abstract: In a semiconductor laser comprising an active layer epitaxially formed on a semiconductor substrate and at least a current limiting layer which defines a current injection region of a stripe shape,the improvement is that said substrate has a terrace part on its principle face,said active layer has two parallel bending parts defining a stripe shape active region facing said current injection region in between andsaid stripe shape active region is disposed with a specified angle to said principle face.

Abstract: On an n-type semiconductor substrate having a ridge part of stripe-shaped pattern, the following layers are formed by liquid phase sequential epitaxial growth: an undoped active layer; a p-type clad layer; and an n-type isolation layer. Thereafter, a Cd impurity is diffused in the isolation layer in a stripe-shaped pattern at the position above the ridge part, thereby forming a p+-type conduction region in the central part of the isolation layer. By forming the stripe-shaped ridge part on the substrate overriding the active layer, the injected current is effectively confined to the lasing region which is the thinner part of the active layer and is on the ridge part. Therefore the threshold current is decreased. Accordingly, the light lased in the active layer is effectively confined in a stripe-shaped lasing region thereof, and a stable transverse mode of lasing is obtainable.

Abstract: The invention provides a novel curable epoxy resin composition suitable for resin encapsulation of various electronic devices such as transistors, ICs, LSIs and the like with high anti-moisture resistance and without causing excessive stress upon curing to the electronic devices. The resin composition comprises an epoxy resin, a curing agent such as a phenol novolac resin, a filler and a curing catalyst such as an imidazole compound as well as an organosilicon polymer represented by the general formula ##STR1## in which R is a monovalent hydrocarbon group such as methyl, Z is a divalent organic group such as ethylene and phenylene, n is a positive number of at least 10 on an average and a and b are each zero or a positive number not exceeding 1 with the proviso that a+b is in the range from 1 to 2 inclusive, in a limited amount.

Abstract: The invention provides a novel rubber composition based on an ethylene-propylene copolymeric rubbery elastomer and curable by hot air vulcanization under atmospheric pressure giving great advantages over conventional ones vulcanizable only under pressure. The inventive rubber composition comprises, in addition to the ethylene-propylene copolymeric rubbery elastomer, an oganopolysiloxane gum having alkenyl or mercapto groups in the molecule, a reinforcing silica filler, an organic compound having at least two maleimido groups in a molecule and a curing agent which is an organic peroxide or an organic sulfur compound.

Abstract: In a semiconductor laser which has epitaxial layers including an active layer on a semiconductor substrate, a buffer layer is formed neighboring the active layer, in order to prevent undesirable diffusion of a highly diffusing dopant (Zn) into the active layer from an adjacent layer such as the second clad layer. The buffer layer has the same conductivity as that of the adjacent layer, has a broader energy gap than the active layer, and the dopant of the buffer layer is less diffusing than that of the adjacent layer.

Abstract: In a semiconductor laser, an n-type first clad layer, an undoped active layer, and a p-type second clad layer are formed on an n-type semiconductor substrate by liquid phase sequential epitaxial growth. The second clad layer is photo-etched to form a stripe-shaped thicker part at the center and thinner parts on both sides thereof. Thereafter, an n-type isolation layer is further epitaxially formed, and a Zn impurity is diffused in a thinner part of the isolation layer in a stripe-shaped pattern at the position above the thicker part, thereby forming a p+-type conduction region in the central part of the thinner part of the n-type isolation layer. By forming the stripe-shaped ridge part in the clad layer, light lased in the active layer is effectively confined in a stripe-shaped part thereof which is underneath the ridge part. Therefore, a stable transverse mode of lasing results.