Abstract: A shock tube assembly for simulating high energy detonations includes a driver section, a diaphragm section, an expansion nozzle, an expansion tube and an improved system for providing a heated and pressurized gas for the driver. After preheating the improved pebble-bed evaporator and superheater, gas or liquefied gas from a pressurized supply flows temperature. The output of the pebble-bedheater flows through a mixer for control of the temperature of the gas used to charge the driver. The pebble-bed heater is preferably vertically oriented and includes spaced baffles having flow apertures arranged in concentric circles. The apertures of each circle are connected by a groove to permit flow of gas through the aperture in the event that a pebble element rests on the open end of the aperture.

Abstract: A shock tube assembly for simulating high energy detonations includes a driver section, a diaphragm section, an expansion nozzle, an expansion tube and an improved system for providing a heated and pressurized gas for the driver. After preheating the improved pebble-bed evaporator and superheater, gas or liquefied gas from a pressurized supply flows therethrough and is heated to a predetermined initial temperature. The output of the pebble-bedheater flows through a mixer for control of the temperature of the gas used to charge the driver. The pebble-bed heater is preferably vertically oriented and includes spaced baffles having flow apertures arranged in concentric circles. The apertures of each circle are connected by a groove to permit flow of gas through the aperture in the event that a pebble element rests on the open end of the aperture.

Abstract: An atomic resonance filter device. The device includes a bulbous shaped cell containing atomic vapor which converts narrow band received light into longer wavelength photons which are collected by an integrated sphere like housing and a spatial collecting cone to which passes the longer wavelength photons to a photodector. The housing has an inner reflective surface or coating which reflects received light and converted light frequencies. The housing opening is covered with a filter that passes the received light and blocks the spectrum of converted light. The inner surface of the filter is coated with a coating highly reflective to converted light. A light collecting cone with a cylindrical body portion is centrally positioned in the bottom of the cesium cell on the surface of the housing opposite the housing opening and the cylindrical portion passes through the wall of the housing to the exterior. Collecting cone improves light collection to the photodetector by about 50%.

Abstract: Methods and apparatus for writing and reading data provide storage in a volume of memory material consisting of inhomogenously broadened absorption centers such that a beam of electromagnetic radiation controlled to be independently steered and simultaneously shifted in wavelength can access information stored in four independent dimensions, three spatial and one spectral. The memory medium can be utilized to write and read a selectable connection matrix between two completely populated two-dimensional memory planes.

Abstract: A high-speed broadband tunable laser system is disclosed. In one illustrated embodiment, a microprocessor-controlled synchronous tunable laser system is disclosed having multiple tuning elements. The tuning elements can be individual birefringent crystals (such as potassium deuterated hydrogen phosphate) which exhibit electro-optic effects when electric field is applied. Two (or more) of such elements provide coarse and progressively finer control over the wavelength and linewidth. The appropriate voltage values for each element can be stored in a random access memory within a controller and retrieved immediately to obtain a desired wavelength within milliseconds without the scanning delays inherent in mechanical systems.

Abstract: Image comparison is accomplished by forming a composite image composed of a reference image and a test image. A two-dimensional image spectrum is generated from the composite image and then is whitened by setting the magnitude of every point of the two-dimensional image spectrum to a uniform level. A phase-only image of the composite image is then constructed, and values of the phase-only image exceeding a predetermined threshold are detected as an indication of the location of a difference between the reference and test images.