A motion analyzer is used to capture and store high-speed images. Once the images are stored they may be reviewed in slow motion while quantitative measurements can be made for analysis. New techniques for capturing images are now available in a high speed motion analyzer. These new image capturing techniques have opened the technology door for new opportunities and allows the use of motion analysis in ways not feasible before. Current motion analysis design philosophy uses magnetic tape as the storage medium for recording images. The advantages of this medium high density and non-volatility have been used in the SP2000 Motion Analysis System and KODAK EKTAPRO 1000 Motion Analyzer. Based on industrial experience with motion analysis new image capturing techniques have been developed. These new image capturing techniques are well suited for imaging repetitive processes continuous flow processes controlled events uncontrolled events and varying demand events. An important part of these new image capturing techniques is electronic triggering. The electronic trigger is used to detect a physical phenomena unique to the event to be recorded. The phenomena that sets the trigger can be as simple as a flash switch closure sound temperature or a voltage change. Trigger requirements are application specific. Determining the trigger requirements will require innovation and creativity by the user of the motion analyzer. Given a set of detectors and the hardware for interfacing their outputs the user need to determine the setup to detect the phenomena unique to the event recorded. This paper will address the new image capturing techniques and their application to high speed motion analysis. 2 / SPIE Vol. 1346 Ultrahigh- and High-Speed Photography Videography Photonics and Velocimetry ''90

High speed events that are random in nature extreme in size or speed or have other challenging characteristics can be difficult or impossible to study using conventional high speed imaging techniques. New methods are required to capture images of such demanding applications. Recent technical advances applied to the design of electronic high speed imaging systems have resulted in entirely new tools and techniques for capturing images of fast and unpredictable events and expanding the conditions under which images can be made. The advances include a completely new high speed image recording technology and a special camera. The new recording device represents a revolution in the field of high speed imaging. The recorder stores digital images directly into solid state memory. The use of solid state memory offers a number of unique image capture modes very high picture quality and excellent performance under harsh environmental conditions. The special camera incorporates a dual stage image intensifier to overcome the traditional problems encountered with the lighting and exposure of high speed events. The cameras extreme light sensitivity allows images to be made under ambient illumination at high framing rates. The camera can also be gated to provide exposures as short as 10 microseconds resulting in blur free pictures like those generally obtained through the use of short duration strobes. The improvements in sensitivity and shuttering when compared to ordinary high speed video equipment results

Operators of long-span overhead cranes can be subjected to high levels of vibration when the control cab is located on the trolley or at the centre of the bridge. This can cause reduced comfort fatigue or injury to an operator. The paper describes a program to solve this problem in two long-span slab handling cranes at a major steel plant. The use of highspeed video motion analysis equipment to record the effects of a dropped test load is highlighted in the solution of the problem. 1.

A high-speed video instrumentation system has been developed that records and stores video images at data rates up to 12000 frames per second. The unique features of this system are: (1) the high-data rate (2) real time processing of the image to detect the occurrence of events for automatic triggering and storage of the images and (3) digital storage and playback of the images on a PC based computer system. The sensor is a 64x64 silicon photodiode array the real time processor uses three custom microprogrammed 9101 ALUs and the data is stored in 16 Megabytes of dynamic RAM. A PC AT computer controls the instrumentation system. The PC is used for programming of event triggering algorithms permanent storage of the images display of the images and analysis of the images. This paper presents a description of the system design configuration an analysis of the sensitivity and speed performance capabilities of the system and a discussion of memory modifications that are currently being demonstrated to increase the data rates to 24 frames per second. Video images captured with the camera are included.

Most of man's technical creations are the direct result of attempts to solve a clearly perceived need or problem. Man's creative ability to envision new devices and technologies has been the wellspring of technological progress. The sensor most used in this process is the human eye. The difficulty today is that the "problems and needs" requiring solutions, frequently are no longer visible to the unaided human eye. This springs the development of today's advanced observation/measurement sensors and systems. It is disconcerting to realize that many of the most capable scientists are striving to solve important problems without the knowledge or benefit of today's diagnostic and observation tools. Most quality versions of these tools or visual aids have been meticulously organized into building blocks for the express purpose of being incorporated into easily configured but highly sophisticated measurement systems. Such systems can be rapidly structured to address specific observation and measurement needs. The age-old adage echoed repeatedly through the halls of science, "If I can see the problem I can solve it," need not be ignored.

Continuous efforts to " see in the dark" have resulted in technology which can be incorporated with a video camera and electronic control circuitry to provide an instrument capable of low light and ultra high speed event imaging. This paper will construct in building block fashion a scientific instrument from the basic technological elements and explore its versatility and application to image capture and motion analysis.

Optical standards will play an increasingly vital role in optical design, manufacture and testing as optics replace electronics and become the information transfer and analysis media of the 21st century. We will first describe the function and importance of optical standards to the optics community. Then we will describe the status of domestic optical standards and the government position on standards in general. This is followed by a summary of the work being done on international standards for optics. We conclude with a plan for the future that will keep the US optical industry from falling further behind our international competition.

Considerable strides have been made in the field of automatic transfer of CAD/CAM data in the last decade. Success in the use of the Initial Graphics Exchange Standard (IGES) for the transfer of optomechanical data has been reported at regular intervals since 1986. Nevertheless IGES has demonstrated some weaknesses with respect to mechanical drafting entities and appears to suffer from excessively large file structures yielding inadequate data precision for the representation of optical systems. Recognizing these voids in the representation of optical models a task group under the International Organization for Standardization (ISO) has undertaken the development of a completely new standard for the transfer of optical model data. NODIF as it is called represents a very ambitious effort to transfer optical data without any reliance on traditional graphical representation. In so doing it is significantly different from IGES and thus should not be regarded as a competing standard. Rather NODIF promises to compliment IGES as a subset of the STEP standard. L

The standards governing optical products to be sold within the European Cannon Market are now being written and this society cannot sit on the sidelines while the rules of canpetition are being established.

The use of international standards to further trade is one of the objectives of creating a standard. By having form fit and function compatible the free interchange of manufactured goods can be handled without hindrance. Unfortunately by setting up standards that are peculiar to a particular country or district it is possible to exclude competition from a group of manufacturers. A major effort is now underway to develop international laser standards. In the May I 990 issue of Laser Focus World Donald R. Johnson the director of industrial technology services for the National Institute of Standards and Technology (NIST formerly the National Bureau of Standards) is quoted as follows: " The common means of protectionism has been through certification for the market place. " The article goes on to say " Mr. Johnson expects this tradition to continue and that the new European Community (EC) will demand not just safety standards but performance standards as well. . . . the American laser industry must move very quickly on this issue or risk being left behind the European standards bandwagon. " The article continues laser companies must get involved in the actual standards negotiating process if they are to have a say in future policy. A single set of standards would reduce the need to repeatedly recalibrate products for different national markets. " As a member of ISO TC-72 SC9 I am

The Fabry Perot has become an important and valuable tool by which explosive performance information can be obtained relatively easily and inexpensively. Principle uses of the Fabry Perot have been free surface, and particle velocity measurements in one dimensional studies of explosive performance. In the cylinder test, it has been very useful to resolve early wall motions. We have refined methods of characterizing new explosives i.e. equation of state, C-J pressure, via the cylinder shot, flat plate, and particle velocity techniques. All of these use Fabry Perot as one of the principle diagnostics. Each of these experimental techniques are discussed briefly and some of the results obtained. Modeling developed to fit Fabry-Perot results are described along with future testing.

The Fabry-Perot (F-P) velocimeter is our main diagnostic tool for hypervelocity impact experiments with the electric gun. Because of its immunity to electromagnetic interference F-P velocimetry is well suited to studying the performanceof flyers providing data on velocity calibration acceleration characteristics and material erosion as well as spallation of various materials under high-velocity impact measurement of impact pressure pulses and Hugoniot measurements of composite materials. We present results and data from selected experiments and compare them with code predictions. 1.

Removing a narrow stripe of the reflective coating from the input mirror of a Fabry-Perot interferometer can dramatically increase the amount of light transmitted through the system we have observed gains in excess of 50 when we compare a conventional Fabry-Perot with the striped Fabry-Perot under similar lighting conditions. The stripe affects the distribution of light in the Fabry-Perot peaks causing them to be lower in the center of the pattern. We examine this distribution and discuss its application in analyzing velocities. 1.

A method for measuring the velocity history of a line element on a shock-loaded solid has been demonstrated. Light from a single-frequency laser is focused through a cylindrical lens to a line on a moving target. The return Doppler-shifted image is passed through a Fabry-Perot interferometer. Because only specific combinations of incident light angle and frequency can pass through the interferometer the output is an incomplete image of the moving target appearing as a set of fringes. This image is focused onto an electronic streak camera and swept in time. The fringe pattern changes with time as the target surface moves allowing determination of velocity for each point on the target that forms a fringe. Because the velocity can only be measured at the fringe positions it is necessary to use an interpolating polynomial to obtain a continuous function of time and velocity along the sampled line. 1.

This paper describes a Velocity Interferometer System for Any Reflector (VISAR) technique that extends velocity measurements from single points to a line. Single-frequency argon laser light was focused through a cylindrical lens to illuminate a line on a surface. The initially stationary flat surface was accelerated unevenly during the experiment. Motion produced a Doppler-shift of light reflected from the surface that was proportional to the velocity at each point. The Dopplershifted image of the illuminated line was focused from the surface through a pushpull VISAR interferometer where the light was split into four quadrature-coded images. When the surface accelerated the Doppler-shift caused the interference for each point on each line image to oscillate sinusoidally. Coherent fiber optic bundles transmitted images from the interferometer to an electronic streak camera for sweeping in time and recording on film. Data reduction combined the images to yield a continuous velocity and displacement history for all points on the surface that reflected sufficient light. The technique was demonsirated in an experiment where most of the surface was rapidly driven to a saddle shape by an exploding foil. Computer graphics were used to display the measured velocity history and to aid visualization of the surface motion. 1.

A Velocity Interferometer System for Any Reflector (VISAR) is a laboratory tool that measures high velocities by continuously measuring the Doppler shift of laser light reflected from a moving surface. It produces lower output frequencies than a displacement interferometer in which Doppler-shifted laser light from a moving target is mixed with unshifted laser light. To obtain lower frequencies a VISAR employs a wide-angle Michelson interferometer with a time delay in one leg. Undelayed and delayed light rays are thus mixed to detect the relatively small difference between two Doppler shifts produced by accelerating motion at two slightly different velocities. In most VISAR data reduction programs the velocity is assumed to be proportional to the interferometer fringe count at any instant. This yields velocity details that are inaccurate over the interferometer delay time. In the examples of this paper the signal time resolution was shorter than the interferometer delay. The subject of this paper is a data reduction method that uses the displacement information in suitable VISAR signals to recover velocity features that occur during the interferometer delay. 1.

A simplified rugged system called VISAR (Velocity Interferometer System for Any Reflector) has been developed using a non-removable delay element and an essentially non-adjustable interferometer cavity. In this system the critical interference adjustments are performed during fabrication of the cavity freeing the user from this task. Prototype systems are easy to use and give extremely high-quality results. 1.

The instantaneous velocity fields of time-dependent flows, or of a collection of objects moving with spatially varying velocities, can be measured by means of digital image velocimetry (DIV). DIV overcomes several shortcomings of such existing techniques as laser-speckle or particle-image velocimetry. Attention is presently given to numerically generated images representing objects in uniform motion which are then used for the experimental validation of DIV.

The DynamicSpatial Reconstructor (DSR) is a 14 x-ray source video imaging system which operates on the computerized tomography scanning principle. It scans a cylindrical volume 18. 5 cm in axial height with equal resolution in the transverse and axial directions and repeats this volume scan (of up to 240 0. 7 mm thick parallel slices) at 16. 67 ms intervals. The output of each of the 14 video imaging systems is A/D converted shading corrected and stored in 64 megabytes of memory. The memory is used efficiently because the shading correction reduces the gray scale information of the pixels from 12 to 10 bits and because we need record only a selectable region of interest within the full video image. 1_. THE DSR SCANNER SYSTEM The DSR imaging system (Figure 1) consists of 14 rotating-anodeS x-ray sources which sequentially irradiate the object of study during the first 10. 5 ms of each 16. 67 ms sequence. '' Figure 1 - Photograph of the DSR scanner. Note several of the x-ray tubes in left upper corner and array of TV camera electronics in middle. Scanner is cantilevered from bearing just to left of person on left. Tail end of a slip ring assembly is just visible to right of person a t r igh t . High vo 1 tage supp ly is in right lower corner. The x-ray sources lie in

This research effort in ballistic holography has resulted in improved images of very high-speed impacts and has pointed the way to extended applications of this novel technique. A pulsed ruby laser is used to record the desired event on a semicylindrical film configuration. This has the important advantage of allowing the user to select post-event optimal three-dimensional views of the scene. Recent advances in recording capabilities and a scheme for automated data reduction are described. These make this approach much more attractive for ballistic and other dynamic test operations. 1.

Advancements in image acquisition and processing technology are exceeding the capability of traditional magnetic tape recording. For scientific industrial and military applications a solid state high-density recording medium is required to store data generated at a rate of tens of Gigabits per second from moderate resolution high frame rate imagers. This paper discusses a three-dimensional (3-D) approach to memory packaging developed jointly by DARPA and Texas Instruments (TI). This packaging approach makes it feasible to economically produce a small rugged recorder for high speed solid state imaging applications. 1.

Z-Plane memory packaging technology utilizes the process of stacking integrated circuits (ICs) to each other in order to increase packaging density. This paper will discuss how Z-plane technology can be applied to memory systems used in high frame-rate imaging systems. 1.

The Aeroballistic Research Facility is one of several free-flight aerodynamic research facilities in the world and has gained a reputation as one of the most accurately instrumented. This facility was developed for the exterior ballistic testing of gyroscopically stabilized fin stabilized or mass stabilized projectiles. Such testing includes bullets missiles and subscale aircraft configurations. The primary source of data for this type of facility is the trajectory information derived from orthogonal pairs of shadowgraph film cameras. The loading unloading processing digitizing and off-line analysis of the film data is extremely costly and time consuming. The unavailability of even unreduced images for subjective evaluation often means delays of days between experiments. In this paper we describe evaluation of an advanced still video system as the baseline for development of an integrated real-time electronic shadowgraph to replace the film cameras for normal range operations. 1.

There is a well documented desire in the scientific research, development and test community to supplement and replace high speed film cameras with electronic imaging systems where immediate results are needed. Examples of the development of commercially practical systems were demonstrated by the Spin Physics SP-2000, and Ektapro 1000 as well as medium speed systems from NAG of Japan. LHESA of France has recently anounced the development of a new high speed system capable of 2000 frames per second-. Battelle Memorial Institute in Columbus, Ohio has developed a prototype of a high speedA low resolution, self triggering system (64 by 64 at 11,000 frames per second)L. All of the systems are constrained by two common problems: limited resolution and light sensitivity, as compared with traditional film and conventional video type instrumentation systems. Incremental advances have been made to improve the light sensitivity and operational utility of the current generation systems. Among these improvements have been the image intensified Ektapro and Solid tate storage module both from Spin Physics (Motion Analysis Division of Kodak.

Digital image processing has been used to measure projectile velocity and spin rate from pairs of synchro-ballistic camera images. Two cameras displaced along the flight path are used. Each image contains the projectile image and timing marks to determine the time scale. Both cameras use the same timing generator allowing a common timing mark denoting the same instant to be defined in both images. Velocity is determined from the actual projectile length the length in the image and the time scale. A circumferential sawtooth pattern painted on the projectile is used to determine the rotation angle in each of the two images. The distance between the common timing mark and the. projectile tip is used to determine the time at which the projectile passes each camera. The spin rate is computed as the angle difference divided by the time difference. The user interface is organized as a computer spreadsheet input values may be entered in any order. The operator recognizes the key points in the image and digitizes their coordinates using an operator-controlled trackball. Interactive contrast enhancement image scrolling and zoom are provided. The measurement accuracy is comparable to manual methods but the time required is significantly reduced.

Time-resolved radiography is the creation of an x-ray image for which both the start-exposure and stop-exposure times are known with respect to the event under study. The combination of image and timing are used to derive information about the event. We have applied time-resolved radiography to evaluate motions of explosive-driven events. In the particular application discussed here our intent is to measure maximum deflections of the components involved. Exposures are made during the time just before to just after the event of interest occurs. A smear or blur of motion out to its furthest extent is recorded on the image. Comparision of the dynamic images with static images allows deflection measurements to be made. 1. TIME-RESOLVED RADIOGRAPHY The concept of time-resolved radiography (TRR) is outlined in the following steps. a) The subject is continuously irradiated with x-rays to form an image on a suitably fast phosphor screen placed behind the subject. (The continuous xray source actually needs only to be stably on during the exposure period. ) b) The phosphor screen is viewed by a gated camera. c) A trigger signal is available to indicate the start of the event. d) The camera gate is opened for a selected duration exposure after a selected delay following the trigger. The basic idea is to acquire an image over a selected period of time known with respect to the event of interest. 1.

An analytical model of the scattered radiation obtained in flash radiography is described. Scatter is related to the areal masses of the object through a function depending on the energy and the object-to-receptor distance. Some particular cases are developed. Monte-Carlo simulations are used to verify the accuracy of the model. 1

The purpose of this paper is a new application of the already known in optics half-filter bootstrap method in the frame of radiography in order to calibrate X film pack detectors. The key to this method is the practical calculation of a "grey filter" in the range of hard X rays (1MeV maxi.).

Several types of pyrotechnic igniters have been evaluated using the technique of laser-illuminated high speed photography with a copper vapor laser. The accompanying video tape shows the results of high speed filras recorded for two types of igniters (Type Xl and Type X2) fired in confinement in a lucite block and four types of igniters (Type Xl, Type X2, Type X3, and Type X4) igniters fired at aiabient. The films of the Type Xl and Type X2 igniters were recorded for both a coarse particle titanium potassium perchlorate (TiKP) output charge and a fine particle TiKP output charge. The results of these films are most informative, and the technique is shown to be useful as a design tool for studying the performance of igniters.

In high explosives designed for air blast cratering fragmentation and underwater applications metallic additives chemically react with the oxidizer and are used to tailor the rate of energy delivery by the expansion medium. Although the specific mechanism for sustained metal combustion in the dense detonation medium remains in question it is generally accepted that the fragmentation of the molten particle and disruption of its oxide layer are a necessity. In this study we use high speed microphotography to examine the ignition and combustion of small 25-76 jim diameter and 23 mm long aluminum wires rapidly heated by a capacitor discharge system in water. Streak and framing photographs detailing the combustion phenomenon and the fragmentation of the molten aluminum were obtained over periods of 100 nsec - 100 j. tsec with a spatial resolution of 2 . im. The wire temperature was determined as a function of time by integrating the circuit equation together with the energy equation for an adiabatic wire and incorporating known aluminum electrical resistivity and temperature functions of energy density in the integration. In order for the aluminum to sustain a rapid chemical reaction with the water we found that the wire temperature has to be raised above the melting temperature of aluminum oxide. The triggering mechanism for this rapid reaction appears to be the fragmentation of the molten aluminum from the collapse of a vapor blanket about

The complex pressure profiles or better the shocked volume of shock waves induced in specimens by detonating high explosive arrangements can be measured with a single test if the shock velocities are observed in a large plexiglas-block with both high time and especially also high space resolution. A " large" plexiglass block is necessary that the rarefaction wave from the surfaces is not able to influence the shock profile from the source. The time resolution is generally no problem if an adequate rotating mirror camera is used. High space resolution can also be obtained if a fine grid is used - in this case of 0. 1 mm strips spaced 0. 4 mm apart and glued in the center plan of the plexiglass block. This technique shows that the shock profile for a high explosive charge without any cover plate gives the highest peak pressure which decays quickly. The detonating high explosive charge which is covered with a two millimeter thick disc of copper shows a shock profile which is constant over a certain time. An airgap between the high explosive charge and the measuring plexiglass block always gives a weak shockwave in the beginning. In the case of an uncovered high explosive charge the expansion of the high explosive products gives a fairly smoothly increasing blast or shock wave and in the case of a covered high explosive charge a

A camera system has been developed by Cordin to combine the advantages of rotating drum framing cameras with the short exposure time and precise control of laser illumination. A sequence of 500 frames may be exposed on a wide variety of 35mm or 70mm films with high resolution. The camera has been equipped with optical sensors to provide a laser trigger synchronized to the exposure window of each frame. The exposure sequence may be event initiated since this is a continuous access camera.

Since giant pulse laser has unique characters of highbrightness narrow pulse width and good monochroaaticity laser highspeed photography is widely used to weapons measures and tests. For photography of highvelocity transient processes with selfflash phenomena only laser highspeed photography system can overcome the confusions from the seLfflash and obtain clear pictures of the phenomena. This paper introduces the configurations and operation principles of" three kinds of laser highspeed photography systems used to laboratory and small range" " YDS system used to take pictures of projectile attitudes at the gun muzzle of the heavy calibre gun" and " lasermoire threedimensional highspeed photography system" also experimental results are briefly introduced.

The flat-field profile of LLNL streak cameras fitted with either S-i or S-20 photocathode tubes is monitored and updated periodically. This paper will describe how these streak camera flat-fields change over the course of 12 to 25 months as well as research into the processes which drive this degradation. 1.

The laser beams irradiating a target at the Nova laser facility comprise a set of ten simultaneous events. Two streak cameras whose resolutions are 40 ps record the power history for each beam five beams to a camera their time bases are cross-timed with a fiducial pulse. Analysis of data recorded for target experiments conducted over a six month period show the precision for cross-timing signals between two streak cameras to be ps and for characterizing a single temporal feature of a pulse to be ps. Beam synchronization at the end of six months was within 20 ps of the synchronization at the beginning of the experiments. A beam timing shift greater than 25 ps can be detected on a single laser shot shifts of 10 to 20 ps require several shots to detect. 1 .

A standard LLNL streak camera has been used to analyze high contrast pulses on the Nova laser facility. These pulses have a plateau at their leading edge (foot) with an amplitude which is approximately 1 of the maximum pulse height. Relying on other features of the pulses and on signal multiplexing we were able to determine how accurately the foot amplitude was being represented by the camera. Results indicate that the useful single channel dynamic range of the instrument approaches 100:1. 1. BACKGROUND Requirements for achieving power balance among the ten Nova beamlines demand that complex pulse shapes be measured with accuracy of better than 10 at all points in time. The standard instrument used to measure pulseshape is the LLNL streak camera. While this streak camera has a well understood sweep rate and flat field response1 its small signal response is less certain. The purpose of this work is to determine the minimum on-line signal level that meets the 10 accuracy specification. As a final " footnote" regarding the background of the title since we are analyzing a (pulse) foot to see how healthy (accurate) it is the colloquialism " pulse podiatry" seemed appropriate. 1. 1. The LLNL streak camera The LLNL streak camera uses a large format streak tube coupled to a 40mm diameter microchannel plate intensifier. The intensifier output is imaged through a lens onto a CCD chip

Common streak camera phosphors such as P-i 1 and P-20 have conversion efficiencies that depend on the duration of the excitation pulse. This reciprocity failure leads to the poor sensitivity that has been reported for streak camera systems. An alternative phosphor P-46 which has a very short persistence time appears to have a more linear response. In this paper we report on the conversion efficiency of these phosphors as measured with a photometrically calibrated CCD as well as a study of the rise and fall times of the phosphorescence. Excitation pulse durations range from 20 ps to 300 ms. 1.

The Inertial Confinement Fusion program at LLNL is becoming increasingly dependent on time-resolved, two-dimensional X-ray imaging for measurement of target dynamics'. A gated X-ray imaging module has been developed over the last several years and has evolved into a "standard" design. This design makes use of primarily mass-produced components, with customized image area characteristics defined by the geometry of an electrode evaporated onto the front surface of a microchannel plate (MCP). As a result, we now have eight imaging modules operating on Nova and will be adding five more in the next few months. In the past year, in addition to assembling and installing gated imaging modules, we have also measured their performance characteristics and investigated possible enhancements for future (or retro-fitted) modules. We have been looking at the entire process from detection of an X-ray photon to digitization of the photographic film. A companion paper2 describes efforts to further reduce the aperture time by using thinned MCP's. In this paper, we focus on results associated with the spatial resolution and noise of the imaging module and the image recording process. We first present the performance characteristics of the standard imaging module; then describe potential enhancements to the performance. In the course of this work, we made measurements of the transverse electron energy distribution at the exit of the MCP. Results are reported for both DC and pulsed MCP bias voltage, and the differences are analyzed. We also investigated an alternative phosphor screen and studied the noise and sensitivity of various photographic films.

Measurements of the x-ray gate time of 0. 2 mm thick microchannel plates with an LID aspect ratio of 20 as opposed to the more usual L/D demonstrate that gate times of 35 PS can be achieved. Good agreement with time dependent modelling is demonstrated L

The generation ofkilovolt-level sub-lOOps wide pulses using the avalanche transit-time effect in abruptjunction P-i-NN+ silicon diodes is described and the basic theory for this " single-shot" mode of the microwave TRAPATF oscillator is discussed. We then present a computationally efficient SPICE model and compare simulations to lab data for two basic circuit configurations. 1.

In this paper, an attempt is made to study the photoemission from quantum well, quantuni wires and q,uantum dots of ultrafast electronic materials taking n-CdGeAs as an example. The above class of materials are being increasingly used in light end.tting diodes. We have formulated the photoernission from the aforeznentioned ultrafast electronic materials by deducing the,new carrier energy spec tra in all c ase s, witbi ri the framework o f k •p. formal Is taking into account various types of anisotropies of the energy band parameters of the said systems. It :I.s found, that the photo emission increases with incident photon energy in a ladder like manner and also exhibits oscillatory dependences with changing film thickne ss and the c arrier density re spec tively for all the cases. The numerical values of the photoeniission is greatest in quantum dots and least in quantum wells. The well-known results have been shown as special cases under certain limiting conditions of our generalized expressions, The theoretical formulations are in agreement with. the experimental observations as reported elsewhere.

To find out homogeneous line-shaped plasma as a gain mediuni of soft Xray lasers produced by linefocused lasers the hydrodynamic characteristics and forms of harmonic and X-ray emission profiles of the plasma colunu-is have been studied with optical diagnostic equipments such as the five-frame laser probing diagnostic system the micrographic diagnostic systems and the spectral resolved Xray pinhole camera. Some experimental results are given and the emphasis is put on those of the halfcylindricalgroove shell targets. The results show that the halfcylindrical groove shell target may be favorable for soft X-ray laser research. 1 .

A high vacuum high voltage linear accelerator tube referred to as a DIGICON is used for the collection of low light level signals. Two techniques are described for gating the tube on and off to extend photocathode lifetime and to reject unwanted signals.

Over the past few years copper vapor lasers have become an important tool in high speed photography as a high-tech strobe lighting source. The short flash duration ( 025 microseconds) high brightness (of the order of 20 million Lumens) and high flash rates (32 per second from a single laser 96 per second from three lasers) of copper vapor lasers have enabled high resolution analysis of processes that previously could not be explored using conventional incandescent continuous or strobe lighting sources. A summary of applications that have benefited from the use of copper laser lighting will be presented. These applications include: analysis of shock waves in turbine engine blades analysis of spinning fibers in the textile industry analysis of the bursting of high pressure storage vessels analysis of turbulent flow in internal combustion engines and capture of ballistic data of objects travelling in excess of 1500ms1(3 mph). Discussion of why copper laser lighting was crucial in each of these applications will be presented.

Highspeed framing cameras are basic diagnostic tools for recording shortlived transient optical events. We have designed built and tested three types of fast framing cameras operating in the visible spectral region from 400 mu to 850 nm. The first type of framing camera is the gated proximity-focused microchannel-plate (MCP) image intensifier. Shuttering is achieved by applying a forward-biasing electrical gate pulse to the quiencently reverse-biased photocatode-MCP intensifier. Gating speeds turn-on and turn-off patterns the asymmetric spatial dependence photocathode-MCP bias have been characterized. The second framing camera is based on the image tube PIM-lO5B which incorporates a photocathode a shutter grid a focusing system an anode diaphragm and two pairs mutually perpendicular deflecting plates. The results of dynamics tests of the camera and its principal technical specifications are presented. The third framing camera is based on the image tube consisting of a dissector section and a restorer section. The dissector component is similar to a conventional streak tube exept for the replacement of the phospor screen with a slit aperture plate. The restorer section consists of a set of compensator plates an electron lens restore deflector plates and phosphor screen. This type of image tube was pionired by R. Kalibjian. Dynamic tests of this framing camera are also presented. In this report we wish to present various circuits developed for pulsed operation of subnanosecond framing cameras and to investigate some problems arising

The development of wideaperture Xray image converter tubes (ICT) is reported. These tubes are intended for recording of weak signals from laser produced plasma Xray radiation. The ICT''s operating principle is based on compression of an electron image formed by wide-aperture photocathode. Three types of wide-aperture Xray ICT''s are described and their testing results are also presented. 1.

The flat-field intensity calibrations of ITT downhole streak cameras were previously done with a bandpass filtered flashlamp/integrating sphere combination. However this system had several problems when characterizing ITT streak cameras that were spatially multiplexed. The main problem simply stated was that there was excessive charge build-up on the phosphor screen of the microchannel plate image intensifier (MCPII) before the sweep of the streak camera started. Consequently the swept CCD image had as many as twenty rows of saturated pixels. In addition contamination or charge spillover into other rows of the CCD readout became an issue. This article outlines a better approach for doing flat-field calibrations which avoids the CCD saturation problem.

We have examined the componentdevices used in electro-optic transientrecording systems and studied their contributions to system noise levels. This work includes the investigation of three system configurations: a 1300-nm laser diode system an 810-nm Mach-Zehnder system and a 1300-nm hybrid system. As a result of our work we have developed a method of analysis for determining the theoretical noise sources in electro-optic transient recording systems.

We present a characterization of the significant noise mechanisms in a microchannel image intensifier and CCD image recording system intended for applications in ultrafast imaging systems used at LLNL for nuclear science. The system under study consists of a generation two image intensifier a relay lens and a cooled CCD imaging array of 640 by 1024 pixels. Fixed pattern noise is significantly reduced by flat fielding techniques. The remaining major noise mechanisms are the intensifier shot noise and a noise factor that characterizes the non-idealness of the system. Results are given for the intensifier noise factor'' s functional dependence on input irradiance levels gain settings and accelerating voltages.

Velocity interferomety has been used to determine velocities of miniature laser-driven flyer plates with sub-nanosecond (100 ps typical) time resolution. Since laser-driven flyer plates can have acceleration 101 0 m/s2 and attain 95 of terminal velocity within 20 nanoseconds the acceleration rate and terminal velocity cannot easily and accurately be resolved by current velocity interferometry techinques because of limitiations in temporal resolution of the interferometer and/or spatial resolution for conventional methods of recording raw data. By selecting an interferometer and recording system that is appropriate for the experiment sub-nanosecond time resolution is possible.

A dual channel picosecond resolution streak camera receiver system must be space qualified for the GLRS instrument. This study has focused on the requirements and characteristics of the streak camera tube and its associated electronics with some analysis of the input and output interfaces to the streak camera. The major tradeoffs considered and the baseline streak camera design are discussed. A streak tube design is proposed with an internal high gain microchannel plate and fiberoptic coupling to a solid-state self-scanned CCD array readout assembly. Concerns regarding the reliablility of an avalanche transistor based sweep circuit and the radiation resistance of a CCD camera are highlighted for further study. 1.

A family of specially developed solid-state lasers intended for dynamic calibration of various type streak cameras is presented. The developed lasers are able to generate either ultrasho,rt single pulses or harmonically modulated signals of nanosecond duration. 5±lps light pulses of 0.5% output energy instability were emitted by YAlO :Nd crystal laser with hybrid mode-locking and passive intracavity negative feedback produced by the action of a GaAs plate. After compression of single pulse inside the fiber optics compressor, the minimum available pulse duration approaches 300fs. 100 percent sinousoidally modulated nanosecond optical radiat ion with modulation period adjustable in the 0 .3ps - 6. 6ns range was generated by electro-optical positive feedback Nd:glass laser. Both ultrashort pulses and harmonically modulated radiation were utilized for streak cameras dynamic parameters evaluation. It is shown that for our streak camera equiped with PVOO1 tube its minimum temporal response function approaches to O.7ps, while its intrinsic triggering jitter does not exceed

Traditional multispectral and intensified video technologies are a perfect match for a variety of applications. Described here is an instrument which combines these technologies with advanced microprocessor control and high-speed electronic gating to provide the core for a new type of measurement system. Such a system is particularly suited to remote-sensing work with small aircraft but its high sensitivity and calibration capabilities make it a flexible tool for multispectral measurement detection and classification applications in the laboratory or in the field. 1. A MULTISPECTRAL VIDEO PRIMER Multispectral imaging differs from ordinary imaging in that each scene is separated into several spectral " slices. " Thus a multispectral picture is a set of images from which we can extract not only spatial information but spectral content as well. With the proper image processing techniques objects or substances can be detected or classified by their spectral signatures on a pixel-by-pixel basis. In conventional multispectral video cameras a wheel housing a set of optical filters rotates in front of the camera''s image sensor. This filter wheel spins synchronously to the video scan rate so that for every image output by the camera a different filter exposes the image sensor. Thus the camera outputs a repeating sequence of images each measuring the response of the subject in a different region of the spectrum. The overall spectral response of a conventional multispectral camera is dictated by

The second half of Session 2 consisted of a round table discussion which addressed the action items necessary to increase the involvement of the United States optics and electro-optics community in the defining and implementing of standards. Covered also were the implications if involvement was not forth coming. Participants in the round table discussion were the speakers from the first half of Session II: Bob Parks, Tim Wise, Fortney Shell, and Lincoln Endelman. Also participating were Dennis Caudle and Larry Shaw. The discussion was moderated by Lincoln Endelman.

Abstract not available.