Abstract: An electron beam pumped semiconductor laser screen and an associated fabrication method are described which provide a display screen that has a relatively long operating lifetime, is less expensive to produce, and operates at lower electron voltages and near room temperature conditions. The laser screen includes a multi quantum well active gain region having quantum wells of GaInP and barrier layers of (AlxGa1−x)InP, thereby permitting operation in the visible, red spectrum. Moreover, the first layer epitaxially grown on the sacrificial substrate is an etch stop layer of (GaxAl1−x)yIn1−yP that acts as an etch stop during the subsequent etching of the sacrificial substrate and may also be used to adjust the cavity length to the correct resonance condition. The laser screen also includes an output mirror having alternating layers of two different compositions of GaxAl1−xAs that are epitaxially grown on the multi quantum well active gain region.

Abstract: A self-referencing microdoppler ladar receiver is provided for detecting the vibration of a target based upon an analysis of backscattered signals without a local reference derived from the transmitter. The self-referencing microdoppler ladar receiver includes a frequency shifter for receiving a backscattered signal from the target and for controllably shifting the frequency of the backscattered signal. The self-referencing microdoppler ladar receiver also includes an interferometer, such as a Mach Zender interferometer, for directing portions of the frequency shifted signals along first and second paths of unequal length and for combining the portions of the frequency shifted signals to produce first and second output signals. The self-referencing microdoppler ladar receiver also includes a signal processor for providing a feedback signal to control the frequency shifter based upon differences in the respective power levels of the first and second output signals.

Abstract: A fiber optic receiving antenna is provided that permits the reception of an incident electric field without re-radiating any portion of the incident power. The fiber optic receiving antenna includes a master oscillator for generating a reference signal and a fiber optic interferometer having first and second arms formed of respective optical fibers for receiving the reference signal. The respective electrooptic activity of the optical fibers that form the first and second arms differ such that the signals propagating along the first and second optical fibers will be modulated differently in response to an incident electric field. The fiber optic interferometer also includes a coupler for combining the signals that have propagated along the first and second arms and been differently modulated by the incident electric field.

Abstract: The collimation apparatus includes a plurality of optical fibers for providing respective primary optical signals. The collimation apparatus also includes a plurality of collimating lenses. Each collimating lens collimates the primary optical signals provided by a respective optical fiber. The collimation apparatus further includes a common reflector for reflecting the collimated optical signals back to the respective collimating lens. These reflections produce a return optical signal from each collimated optical signal. The collimation apparatus also includes at least one detector for receiving the return optical signals and a plurality of actuators for iteratively positioning the optical fibers based on the magnitude of the detected signals.

Abstract: An incoherent fiber optic laser system is provided which provides a high quality output beam which is readily scalable and which can be focused to a target location located relatively near or relatively far without requiring sophisticated optical elements. The incoherent fiber optic laser system includes a plurality of single mode laser sources, such as a plurality of fiber optic amplifiers, for providing single mode laser signals. The laser sources, such as the fiber optic amplifiers, operate incoherently with respect to one another such that the resulting laser signals are also incoherent. The incoherent fiber optic laser system also generally includes a plurality of single mode optical fibers for routing the incoherent laser signals as desired. In addition, the incoherent fiber optic laser system can include a plurality of lenses for collimating the incoherent laser signals provided by respective ones of the single mode optical fibers.

Abstract: The multi-channel fiber amplification system and associated method includes a fiber amplifier which solves problems with power poaching by simultaneously amplifying a pair of optical signals in a similar manner even if the fiber amplifier is saturated. The fiber amplifier, has greater absorption than emission for wavelengths immediately less than a reference wavelength and greater emission than absorption for wavelengths immediately greater than the reference wavelength. The multi-channel fiber amplification system also includes a pump source having a Stokes band which includes at least some wavelengths greater than the reference wavelength of the fiber amplifier. The multi-channel fiber amplification system further includes first and second signal sources for providing first and second signals, respectively, having first and second wavelengths, respectively.

Abstract: Disclosed is a heat sink for cooling an integrated circuit package. The heat sink comprises a single thin sheet of material having two oppositely facing major surfaces. These two major surfaces have a common perimeter defining a plurality of spaced-apart finger-shaped portions of the thin sheet of material that extend radially from a central portion of the sheet. The central portion is convex for attachment to the integrated circuit package; and the finger-shaped portions are formed to extend out of the plane of the central portion to become cooling fins for the central portion.

Abstract: Disclosed is an electrical conductor for use in an electro-mechanical connector of the type which holds an integrated circuit package and connects the package to an electrical system in a replaceable fashion. The electrical conductor is comprised of an elongated piece of material having a U-shaped bend to provide two legs; one of the legs also has a bend of approximately 90.degree. in a first direction at a predetermined distance from said U-shaped bend to thereafter provide a first leg portion for pushing against and making ohmic contact with a corresponding lead in said integrated circuit package; and the other leg also has a bend of approximately 90.degree. in the first direction at another predetermined distance from the U-shaped bend, and another bend of approximately 90.degree. further along its length in a direction perpendicular to the first direction to thereafter provide a second leg portion for making ohmic contact with said electrical system.

Abstract: A method and circuitry are disclosed for correcting bit errors introduced by random events in a data recirculating memory, such as a charge coupled memory device or a bubble memory. The bit errors, caused by random events such as by alpha particle bombardment or other causes, are corrected in circuitry that generates row and column parity bits corresponding to various segments of the information stored in the memory. Changes in the row and column parity bits uniquely define the location of failed bits circulating through the memory even though each failed bit has no fixed address, so that error detection circuitry thereafter may correct the error during the next or a subsequent bit recirculating cycle. The invention facilitates the use of very large memories, for example, on the order of one billion bits or more.