Abstract: Laser modules that are operated intermittently are prone to stop operating after only a few thousand cycles or less. The laser modules sometimes experience a significant increase in operating temperature before they stop operating and, in some cases, manifest an opening of the electrical circuit that connects the laser diodes in the stack of laser subassemblies. In extreme cases, the laser module disintegrates into component subassemblies. These problems arise from structural failures in affixing agents like solder that are used to affix component parts to each other. The structural failures are caused by cyclical thermal expansion and contraction of component parts that exceed the elastic limit of the solder.

Abstract: A multistage optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources for pumping a single fiber laser pump source. A second level of redundancy deals with redundancy of a plurality of fiber laser pump sources for pumping a plurality of serially connected injection signal fiber amplifiers forming the multistage amplifier system. If one of fiber pump sources should fail, increased pumping power is available from the remaining fiber pump sources via their respectively connected amplifier stages. A third level of redundancy deals with redundancy in the employment of multiple single mode laser emitters on the same chip or bar sufficiently segmented and/or electrical isolated so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar.

Abstract: A power system for a laser source comprises a plurality of semiconductor lasers or at least one laser array with plurality of independently, electrically addressable emitters. A power supply is independently connected to each of the laser emitters. A fuse device is associated with each of the laser emitters so that an electrical short of any one emitter of a laser will not cause a short to or change the power supplied to other emitters of the laser source.

Abstract: The invention relates to laser diode arrays having high beam quality and high beam brightness. In one approach, a laser diode array package includes a mount and first and second laser diode arrays disposed on the mount. Each of the laser diode arrays defines an optical axis and has an emitting surface lying in an emitting surface plane. The emitting surface plane of the first laser diode array is displaced relative to the emitting surface plane of the second laser diode array in a direction parallel to one of the optical axes. The optical axes of the first and second laser diode arrays are offset from each other in a direction perpendicular to one of the optical axes. First and second lenses are disposed relative to respective emitting surfaces to reduce divergence of light output from the emitting surfaces. In another approach, laser diode array bars are stacked and the individual output beam from each bar is collimated using a short focal length, low aberration lens.

Abstract: An optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources in the lightwave communication system. A second level of redundancy deals with redundancy of multiple single mode laser emitters on the same chip or bar sufficiently segmented so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar. A third level of redundancy deals with redundancy of a plurality of fiber pump sources for pumping a plurality of serially connected injection signal fiber amplifiers.

Abstract: A system and method for operating a high power laser diode device with high efficiency coupling of a laser diode bar. The laser diode bar and a micro-cylinder lens are vertically oriented in a device package, such that the array axis of the laser bar and the longitudinal axis of the micro-cylinder lens are aligned substantially parallel to a gravity vector. In the two different embodiments disclosed, either initial collimation of the fast-axis divergence or, alternatively, initial collimation of both the fast-axis and slow-axis divergences take place before beam reformatting via a beam array turning mirror. Additionally, the vertical orientation of these components is combined with methods of compensating for the bending or "smile" of the laser diode bar to provide for optimal output beam coupling, resulting in a uniform far field intensity distribution.

Abstract: A high-power two-dimensional edge-emitting diode laser array comprises mounting modules, laser bars mounted on the modules, and protective caps mounted on the bars opposite the modules. The lasers are electrically connected in series through the modules and caps. The caps serve as laser bar protectors during the bar burn-in. The caps have grooves which compensate for tolerances in the thicknesses of the lasers, modules, and caps. The array is mounted on a base plate, and is in thermal communication with a heat sink. The caps and/or modules are thermal-expansion-matched to the laser bars. Eliminating the need for a wire bond plate allows shortening the modules.

Abstract: An optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources in the lightwave communication system. A second level of redundancy deals with redundancy of multiple single mode laser emitters on the same chip or bar sufficiently segmented so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar. A third level of deals with redundancy of a plurality of fiber pump sources for pumping a plurality of serially connected injection signal fiber amplifiers.

Abstract: A laser multibeam printer or recorder includes a laser diode array generating multiple modulated parallel and diverging light beams with predetermined light intensities at any instant of time. Optical means reduce the divergence of the parallel light beams from the laser diode array by a predetermined amount, do not focus the light beams in a first cross-section direction along a width of the laser diode array, and focus the light beams onto a plane of an entrance pupil of a printing lens in a second cross-sectional direction normal to the first cross-sectional direction. A separate lenslet of a lenslet array directs a corresponding light beam from the laser diode array towards a predetermined area on a plane in front of the printing lens (e.g., the entrance pupil) in the first cross-sectional direction, and focuses the light beam onto the plane of the entrance pupil in a second cross-sectional direction.

Abstract: A laser array submount structure for assembly into a two-dimensional stacked array with precise separation between laser diodes of adjacent submounts. The submount includes a deformable metal layer, such as a soft solder, on one major surface of a laser array support plate. A spacer element having spaced apart ridges is disposed on the opposite major surface. A laser diode array is mounted on a front edge of the support plate. In a cold bonding step, submounts are pressed together causing ridges to penetrate the deformable metal layer to a specified depth. The displaced metal spreads into channels between the ridges, allowing pressing of multiple laser array submounts into stackes of precise total tolerance.

Abstract: A method of driving a multimode laser diode has pulse circuitry providing a sequence of drive current pulses to the laser and modulation circuitry superimposing a modulation current upon the drive current pulses. When the modulation amplitude and rate are sufficiently great, rapid switching of transverse modes of laser operation is induced during each laser pulse. The effect of many different modes is averaged out so that the observed light output, even in a high power apertured system, is stable both within a single pulse and from one pulse to the next.

Abstract: A compact laser flare illuminator includes a semiconductor diode laser array radiation source, an energy source for the radiation source that can be switched on and a housing which holds the array and energy source, while allowing egress of a beam. This illuminator may be used to facilitate night vision by persons wearing night vision goggles or using other types of wavelength-selective night vision devices. The housing may serve as a heat sink and may be equipped with a propulsion device and with fins for flight stabilization, as well as with a parachute for slowing descent from an altitude above an area to be illuminated. A wavelength filter that passes radiation only in a predetermined wavelength range and a lens or optical element to focus the laser radiation toward the area to be illuminated are optional features.

Abstract: The electron multiplier device is operable in a substantial vacuum and comprises a cathode which emits electrons upon ion bombardment and an electron multiplier section adjacent the cathode for multiplying electrons emitted from the cathode. An output target surface is partially interposed in the path of the electrons near the output of the multiplier. A portion of the electrons released by the multiplier strike the output target surface causing ions to be emitted therefrom. The ions then feed back and bombard the cathode causing it to release more electrons, which in turn are multiplied thereby providing a buildup of electrons leaving the multiplier output. The output electrons may be controlled by an electron control section aligned with the multiplier near its output end.

Abstract: A chain of planar dynodes is divided into two groups which are spaced from and substantially parallel to each other. A cathode which is capable of emitting electrons upon ion bombardment is at one end of the dynode chain. An envelope encloses the dynodes and the cathode. Also enclosed by the envelope are a plurality of shields. Each shield is located so as to prevent gas ions, present within the envelope, from striking the dynodes, while allowing the ions to strike the cathode.

Abstract: An image display device includes at least one display cell having the following in spaced relation: a photocathode; multiplier dynodes, an anode electrode; and a cathodoluminescent screen. In addition to an optical feedback fluorescent material, the anode electrode includes a material which exhibits slow fluorescence, e.g., Y.sub.2 O.sub.3 :Gd3%, such that it emits light energy for a finite time period after it has been excited by electrons. In the operation of the display device, an electrical discharge is employed to produce the desired optical output at the cathodoluminescent screen. Some of the electrons created in the discharge strike the anode electrode, causing light energy to be directed to the photocathode where it is converted into free electrons. The presence of these free electrons ensures the rapid initiation of subsequent electrical discharges. In other embodiments, the electrical discharge may be obtained through ion feedback or plasma discharge.