Abstract: A family of semiconductor diode lasers is made available whose emitted laser light beam intensity can be electrically modulated with low voltage, low current modulating control bias signals. By appropriate design of the diode laser devices in accordance with the invention and provision of means for adjusting the relative values of the applied modulating control bias signals, the improved diode lasers can be switched on and off electrically in addition to modulation of the emitted output laser light beam intensity. Further, the physical position of the emitted laser light beam spot along the laser facet readily can be moved by the same electrically operable control means so as to provide modulation, turn-on and turn-off and small lateral movement as well as scanning of the laser light beam in a single heterostructural diode laser device.

Abstract: An efficient light emitting diode is disclosed wherein the spatial distribution of emitted radiation is highly uniform. In accordance with the present invention, a transparent electrode is used to couple current to the light emitting diode junction in a manner that minimizes the resistance at the interface between the transparent electrode and semiconductor diode material. Specifically, it has been found that the interface resistance is significantly reduced, and device efficiency thus increased, by forming a thin metal-based layer at such interface and/or by annealing the transparent electrode after formation on the device.

Abstract: A valve for use in a pressure differentially operated servo-motor to regulate the flow of fluid through a bore in a hub from first and second sources in response to movement of an input member by an operator. The valve has a resilient disc member with a peripheral surface and a central opening. First and second annular ribs symmetrically extend from opposite sides of the disc adjacent the central opening. A spring connected to the input member holds the peripheral surface in sealing engagement with the hub. In a first mode of operation, the spring holds the input member against the first annular rib to allow the fluid from the first source to freely communicate between first and second passages in the hub by way of the bore.