Abstract: There is provided an n.sup.+ -p-.pi.-p.sup.+ APD having a shallow and abrupt p-n junction located about 1 to 2 .mu.m into the APD and having a p-type conductivity region containing acceptors in an uncompensated excess concentration corresponding to a dose of between about 5 and 10.times.10.sup.11 acceptors/cm.sup.2. The combination of the shallow p-n junction and the doping profile in the p-type concentration region gives rise to an electric field profile having multiplication spread substantially throughout the entire thickness of the central active region of the APD and having no drift region. The electric field profile peaks adjacent the p-n junction in a value of about 2.9.times.10.sup.5 volts/cm. The electric field profile diminishes over the distance that the p-type conductivity region extends into the APD but remains at about 1.6.times.10.sup.5 volts/cm to maintain multiplication throughout the thickness of the active region of the APD.

Abstract: There is provided a super luminescent light emitting device comprising a semiconductor body including a central region and two opposing end regions extending a predetermined distance from the end faces. A gain guiding linear strip of material adjacent to a side of the active region extends between the end faces and is inclined along its longitudinal axis at a predetermined angle relative to a direction normal to at least one of the end faces. An optical beam path of the device has an optical axis of symmetry extending between the end faces parallel to the longitudinal axis of the strip. The beam path has end lateral boundaries at each of the end regions whose lateral carrier and optical confinement is determined by the gain guiding strip to allow light reflected at the end faces to be refracted out of the optical beam path.

Abstract: The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surface. This photodetector includes a light-absorptive region, an active region overlying the absorptive region forming a heterojunction therebetween. The photodetector includes a central zone which has a greater concentration of conductivity modifiers than the remainder of the active region and is located in the active region extending into the absorptive region. A cap region overlies the active region and has the opposite conductivity type. The cap region extends a greater distance in the lateral direction than the central zone. A photodetector having a central zone extending across the heterojunction between the active region and light absorptive region have exhibited response times comparable with those of photodetectors having a quaternary layer located between the active region and the absorptive region.

Abstract: There is disclosed a light emitting device which includes a header and an angle stripe light emitting diode. The header has a longitudinal axis and a forward mounting surface. The forward mounting surface includes a leading edge portion which extends perpendicular to the longitudinal axis. The mounting surface further includes a trailing alignment edge portion which extends rearwardly from the leading edge portion at a predetermined compensating angle. The light emitting diode is affixed in electrical and heat transfer relation to the mounting surface of the header such that the emitting facet is aligned with the trailing alignment edge portion of the header. The trailing alignment edge portion compensates for the offset angle that light is emitted from a stripe light emitting diode.

Abstract: The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surface. This photodetector includes a light-absorptive region, an active region overlying the absorptive region and having a central zone which has a greater concentration of conductivity modifiers than the remainder of the active region. A cap region overlies the first region, has the opposite conductivity type and extends a greater distance in the lateral direction than the central zone. The invention is also a method of forming this detector comprising the steps of forming a first region of the active region, embedding an excess concentration of conductivity modifiers into a portion thereof and then forming a second region of the active region on the first region. A cap region of opposite conductivity type is then formed over the active region. The cap region has a greater lateral extent than the portion containing the excess concentration of conductivity modifiers.

Abstract: The invention is an improved avalanche photodiode having reduced electrical noise arising from spurious surface generation of charge carriers. The avalanche photodiode includes active and neighboring regions adjacent a first surface of a semiconductor body with a gap region therebetween and a channel extending a distance into the semiconductor body from a portion of the second opposed surface opposite the gap region. A P-N junction is formed between regions of opposite conductivity type including a portion thereof over the channel. Since the dopant concentration at the junction is less over the channel, the local avalanche gain over the channel is less, thereby reducing the noise contribution from carriers generated in the gap region.

Abstract: An avalanche photodiode includes a region of second conductivity type extending a distance into a substrate and a region of first conductivity type extending a further distance into the substrate of first conductivity type with a P-N junction therebetween. The invention is a method for fabricating an avalanche photodiode having a specified breakdown voltage. The method includes the step of measuring the concentration of the first type conductivity modifiers and removing a portion of the surface of the substrate prior to forming the region of second conductivity type. This method provides control of the concentration of the first type conductivity modifiers at the P-N junction and thereby controls the breakdown voltage.

Abstract: The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surfaces. This photodetector includes an absorptive region, a first region overlying the absorptive region, a second region overlying the first region and having a central zone which is thinner than a peripheral zone and a third region overlying the second region. The high electric field required for avalanche multiplication is then restricted to the portion of the first region adjacent the central zone while the field at the periphery is less than that necessary for avalanche multiplication.

Abstract: The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surfaces. This photodetector includes an absorptive region, a first region overlying the absorptive region and having a higher concentration zone and a surrounding peripheral zone and a second region overlying the first region. The high electric field in the avalanche region is then restricted to the higher conductivity central zone thereby reducing the electric field at the detector surfaces when a reverse-bias voltage sufficient to produce avalanche multiplication is applied to the detector.

Abstract: The invention relates to an avalanche photodetector having a charge-multiplication region which is spatially separated from the detector surfaces. This photodetector includes an absorptive region, a first region overlying the absorptive region and having a central zone which is thicker than a surrounding peripheral zone and a second region overlying the first region. The avalanche region is then restricted to the thicker central zone of the first region.

Abstract: The invention relates to a photodetector wherein the avalanche region is separated from the detector surfaces by a region in which the electric field under reverse bias will be less than in the avalanche region. This photodetector includes an absorptive region having a planar surface area surrounded by a non-planar surface area. A first region overlies the planar area and a second region of opposite conductivity type overlies both the first region and the non-planar area of the absorptive region. The high electric fields are restricted to the first region which is isolated from the surfaces of the photodetector.

Abstract: A p-.nu.-n Si photodiode having an n-type control layer extended into the silicon body from a portion of the surface contiguous to that portion from which a p-type region extends. Photodiodes incorporating this control layer have a much higher junction resistance.The invention also includes an improved method of making a photodiode which has a reduced number of processing steps. The improvement comprises implanting As or Sb into the surface of a .nu.-type Si body to form an n-type layer prior to the steps of passivating the surface and forming a p-type region extending into the body from the surface.

Abstract: An n-p-.pi.-p.sup.+ Si avalanche photodiode wherein the number of acceptors introduced into a Si body to form the p-type conductivity region has been reduced and this region extends a distance greater than about 35 micrometers into the body from the surface and wherein the n-type conductivity region extends a distance into the body such that the p-n junction is less than about 10 micrometers from the surface of the body. The method of the invention comprises introducing a reduced number of acceptors into the surface of the body, diffusing the acceptors into the body a distance greater than about 35 micrometers and forming an n-type conductivity region such that the p-n junction is less than 10 micrometers from the surface of the device. APDs of the invention exhibit a k.sub.eff of about 0.006 which is a factor of greater than 2.5 less than that of typical prior art devices.

Abstract: The invention is an APD array having a plurality of p-n junctions. The p-n junctions comprise a plurality of separate regions which extend a distance into a semiconductor body from a surface thereof and have a conductivity type opposed to that of the body. A region of the same conductivity type as that of the body extends a further distance into the body and is composed of sub-regions which overlap one another in the direction parallel to the surface of the body. The elements so formed have a more uniform avalanche gain and, because of the overlap of the sub-regions of first conductivity type, the likelihood of electric breakdown at the surface is reduced and the electrical isolation between the elements is increased. Moreover, because of the proximity of the adjacent elements the likelihood of breakdown at the junction edges is reduced.

Abstract: A method and apparatus for welding a header to a heat sensitive cap to form an electro-optic device housing without weld flanges. A collet electrode is used to provide a radially compressive force which provides good electric and thermal contact to the wall of the heat sensitive cap and maintains the glass to metal seal under compression.