| Free-Space Quantum Key Distribution using Multilevel Encoding via Transverse Field Modulation: Preprint |
01-Aug-2009 |
6 pages |
| Authors:
Mark T Gruneisen; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
 | Transverse modulation of the complex optical field defines sets of orthogonal states for multilevel quantum key distribution. Principles of holography are evaluated as a means of generating and sorting the single photon states. |
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| Wavelength Tuning Limitations in Optically Pumped Type-II Antimonide Lasers |
07-Jan-2009 |
6 pages |
| Authors:
A P Ongstad; R Kaspi; G C Dente; M L Tilton; J R Chavez; R Barresi; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| In this paper, we examine the wavelength tuning limitations of type-II antimonide lasers containing InAs/InGaSb/InAs quantum wells. Wavelength tuning is accomplished by varying the thickness of the InAs electron wells while keeping all else fixed. In principle, these wells can be tuned from lambda approximately equal 2.5 m out to far IR wavelengths by increasing the thickness of the InAs layers. However, a practical upper limit of lambda approximately equal ... |
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| A Test Method to Assess the Foldability of Flexible Structural Materials |
APR 2007 |
14 pages |
| Authors:
Thomas W. Murphey; Gregory E. Sanford; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A coupon level comparative test method was developed to assess the foldability of thin flexible materials used in deployable structures. The subject materials support tensile and compressive loads; they are not cloth-like. The non-destructive method consists of a tensile stiffness test and a compressive buckling test and reveals changes in coupon properties that could result from locally extreme strains incurred during folding. The test is intended to provide a standardized ... |
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| High Brightness from an Unstable Resonator Mid-IR Semiconductor (Postprint) |
13 JUN 2006 |
6 pages |
| Authors:
A. P. Ongstad; G. C. Dente; M. L. Tilton; J. C. Chavez; Jr Gianardi D. M.; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| We describe high-brightness, broad-area mid-IR semiconductor lasers. The optically pumped devices achieved higher brightness operation as unstable resonators. Each unstable resonator was realized by polishing or etching a diverging cylindrical mirror at one of the facets. For several mid-IR unstable resonator devices experimental near- and far-fields near threshold are shown, as well as at many times threshold. For an unstable resonator semiconductor laser operating at 4.6 micrometer and at a ... |
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| Studies by a Mesospheric Sodium Guidestar Pumped by Continuous Wave Sum-Frequency Mixing of Two Nd: YAG Laser in Lithium Triborate (Preprint) |
16 MAY 2006 |
11 pages |
| Authors:
John Telle; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Mesospberic sodium guidestar radiance is plotted vs. wavelength, fasor power, fasor polarization and date Peak radiance for circular polarization was about 7000 photons/sec/sq cm (Vl magnitude 5.1) for 30 watts of pump power in November of 2005. Pumping with circular polarization at high power produces about 2 times more return than linear polarization. Pumping D2a at high power produces about 12 times more return than pumping D2b. A lidar equation ... |
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| Three Dimensional PIC Simulations of Novel Cathodes in the Michigan and AFRL Relativistic Magnetrons |
May-2006 |
5 pages |
| Authors:
T P Fleming; P J Mardahl; L A Bowers; K L Cartwright; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Several novel shaped cathodes for a relativistic magnetron were modeled and optimized using a massively parallel electromagnetic particle-in-cell code ICEPIC. The effect of using a shaped cathode to enhance key performance parameters such as output power, power efficiency and impedance, was examined. In simulations we saw a dramatic increase in the range of magnetic field in which the magnetron functions, an increase of output power, an increase in efficiency, an ... |
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| Improvement of the Output Characteristics of a Relativistic Magnetron using a Small Diameter Cathode Surrounded by a Transparent Cathode |
APR 2006 |
2 pages |
| Authors:
L. Bowers; T. Fleming; P. Mardhal; H. Bosman; M. Fuks; S. Prasad; E. Schamiloglu; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Conventional magnetrons in which cathodes with thermionic and/or secondary electron emission are used operate poorly when the ratio of the anode-to-cathode radius is large, R sub a /R sub c > 2~2.5 , because of unfavorable starting conditions and strong mismatch of the synchronous particle-field interaction. The field of the operating mode, which decreases exponentially from the resonant system cavities to the cathode, becomes too weak on the electron flow ... |
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| Fairing Noise Control Using Tube-Shaped Resonators |
AUG 2005 |
8 pages |
| Authors:
Steven A. Lane; Robert E. Richard; Scott J. Kennedy; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The potential for noise mitigation in composite Chamber Core fairings is investigated by using the walls of the fairing structure itself as acoustic resonators. This is the first documented application of long cylindrical tube-shaped resonators for fairing noise control. The theory and modeling of tube-shaped resonators for controlling fairing acoustic resonances is presented. The potential for noise mitigation in composite Chamber Core fairing using the walls of the fairing structure ... |
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| Empirical Pseudopotential Modeling of Superlattices |
08 APR 2005 |
10 pages |
| Authors:
a. Ongstad; M. Tilton; G. Dente; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| For several years, we have been accurately calculating the electronic structure of superlattices using a solution technique based on the Empirical Pseudopotential Method (EOM). In our method for forming the superlattice pseudopotential, the critical assumption is that the heterointerface charges are redistributed, making each constituent layer in the superlattice as bulk-like as possible. Here, we demonstrate that our technique for forming the superlattice pseudopotential is fundamentally different from the atomistic ... |
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| Advanced Iso-Grid Fairing Qualification Test for Minotaur Launch Vehicle |
2003 |
11 pages |
| Authors:
Greg Sanford; John E. Higgins; Jeffry Welsh; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The development of the grid-stiffened fairing to be flown on the Minotaur launch vehicle has made significant progress over the past five years. This qualification structure was subjected to static qualification testing. The 6 m (20 ft) tall fairing was constrticted of a carbon fiber composite grid structure that was over-wrapped to create a laminated skin. Upon completion of curing and machining, the fairing was cut in half to create ... |
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| A New All Gas-Phase Chemical Iodine Laser. Scientists Developed and Demonstrated a New Chemically Pumped Laser |
MAR 2002 |
4 pages |
| Authors:
Gerald C. Manke Ii; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Solid-state lasers convert electrical energy into light using optical excitation. Although efficient, scientists continue research into scaling these devices for high-power applications. Chemical lasers efficiently convert energy derived from chemical bonds and reactions into laser photons. Scientists use chemical lasers for applications that require high-power, lightweight, and self- contained sources of laser radiation because of their inherent high efficiency and scalability. The two classes of chemical lasers are the hydrogen ... |
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| Noise Analysis for Complex Field Estimation Using a Self-Referencing Interferometer Wave Front Sensor (Postprint) |
2002 |
15 pages |
| Authors:
Troy Rhoadarmer; Jeffery D. Barchers; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A noise analysis tor complex field reconstruction from a self-referencing interferometer wave front sensor with an amplified reference is evaluated. The wave front sensor is constructed from a phase-shifting, point diffraction interferometer where the reference field is created by coupling a focal plane image of the input optical filed into an optical amplifier. The noise characteristics of the wave front sensor are examined in terms of the field estimations Strehl. ... |
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| Radiation Effects in Quantum Well Detectors |
OCT 2001 |
24 pages |
| Authors:
Omar Manasreh; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
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| We performed photoluminescence (PL) measurements of interband transitions in InGaAs/AlGaAs multiple quantum wells before and after fast neutron irradiation. It is shown that the intensity of the intersubband transitions is dramatically decreased in heavily irradiated samples, which can be explained in terms of trapping of the two-dimensional electrons by the irradiation induced defects. A negative persistent effect was also observed in the heavily irradiated samples. It is noted that the ... |
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| Reconfigurable Cellular Array Architectures for Molecular Electronics |
MAR 2001 |
136 pages |
| Authors:
James C. Lyke; Gregory Donohoe; Shashi Karna; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| This report is a compilation of largely unpublished work pertaining to reconfigurable cellular arrays for digital computation. They bear resemblance to both cellular automata and cellular neural networks, with the attributes of field programmable gate arrays. They are of potential interest to nano-scale / molecular-scale electronics approaches due to their simple, periodic arrangement. As such they address three critical issues at the smallest physical scales: (1) low-interconnect demand; (2) defect ... |
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| Precision Controlled Actuation and Vibration Isolation Utilizing Magnetorheological (MR) Fluid Technology |
2001 |
9 pages |
| Authors:
Shawn P. Kelso; Ross Blankinship; Benjamin K. Henderson; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| PRECISION CONTROLLED VIBRATIONAL ISOLATION UTILIZING MAGNETORHEOLOGICAL FLUID TECHNOLOGY FOR POTENTIAL SPACE APPLICATIONS, SUCH AS SURVEIILLANCE AND DIRECTED ENERY, IS ADDRESSED. |
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| Priorities, Organization, and Sources of Information Accessed by Pilots in Various Phases of Flight |
JUL 2000 |
42 pages |
| Authors:
Roger Schvaneveldt; Dennis B. Beringer; John Lamonica; Richard Tucker; Christopher Nance; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| In the first project of the study, 27 pilots rated the priority of information required for flight. These pilots were divided by flight experience into novices (65 to 820 hours' flight time) and experienced pilots (1600 to 17, 000 hours' flight time). Participants rated 29 information elements across seven phases of flight. These data show the shifring priorities of information across phases of flight, and some ... |
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| Temporal switching jitter in photoconductive switches. |
JUL 2000 |
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| Authors:
J. A. Gaudet; M. C. Skipper; M. D. Abdalla; S. M. Ahern; S. P. Romero; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
 | Gallium arsenide photoconductive semiconductor switches (PCSS) are being studied as enabling technologies for a variety of applications. High grain PCSS can be triggered with small laser diodes or laser diode arrays. Some of the applications require low temporal jitter of the switches relative to the trigger laser. The purpose of this study was to compare the temporal switch jitter times for different systems: we varied the type of trigger laser ... |
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| Cathode testing at the Air Force Research Laboratory. |
JUL 2000 |
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| Authors:
D. A. Shiffler; M. Lacour; K. Golby; M. D. Sena; R. J. Umstattd; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| An integral part of any vacuum rf device is the cathode. Many rf and microwave tubes utilize thermionic cathodes. However, these cathodes are generally limited to current densities less than 100 A/cm2, a limitation too great for the majority of High Power Microwave tubes. At the Air Force Research Laboratory, Directed Energy Directorate, we have to study a variety of explosive emission cathodes. This paper presents results on studies of ... |
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| Progress in the development of the ferratron: a novel repetitively rated triggered spark-gap switch with ultralow jitter. |
JUL 2000 |
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| Authors:
J. M. Lehr; C. E. Baum; L. H. Bowen; J. M. Elizondo; D. E. Ellerbee; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Low jitter, triggered spark gap switches are highly desirable components for a wide variety of High Power Microwave applications. In particular, this switch enables a wide range of new applications ranging from protection circuitry to high power transient arrays that are currently technically infeasible with the considerable jitter associated with high power switches. The device presently under advanced development is a novel triggering scheme using a ferroelectric ceramic as the ... |
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| Nonlinear characteristics (chaos) of high-power microwave (HPM) sources. |
JUL 2000 |
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| Authors:
J. A. Gaudet; J. W. Luginsland; C. B. Wallace; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
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| Recent advances in the understanding of dynamical systems and chaotic behavior have resulted in the investigation of HPM source design issues. Modern dynamical systems theory can improve our understanding of the dynamics of space charge dominated beams and the RF waveforms generated by them. This paper will review the work done to date using time series analysis techniques to study the state space dynamics of high power microwave sources using ... |
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| Marx generator triggering with photoconductive switches. |
JUL 2000 |
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| Authors:
J. M. Lehr; S. M. Ahern; M. D. Abdalla; M. C. Skipper; S. P. Romero; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Fast rising, high-voltage, low jitter trigger pulses have been in high demand for a variety of applications. A recent application required triggering a compact Marx generator with very low trigger jitter. The lateral gallium arsenide photoconductive semiconductor switch (PCSS) being developed at the Air Force Research Laboratory (AFRL) has been implemented in this application. PCSS technology is an attractive solution because of the very low trigger jitter, high voltage switching ... |
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| Design and implementation of a new UHV threshold cathode test facility. |
JUL 2000 |
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| Authors:
R. J. Umstattd; D. A. Shiffler; C. A. Baca; K. J. Hendricks; T. A. Spencer; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| In support of cathode development at the Air Force Research Laboratory, a new ultra-high vacuum cathode test facility is being assembled to complement the existing repetition-rate test pulser. The existing test bed is a 500 kV, 100 Ohm, 1 microsecond(s) duration pulser capable of firing at up to 1 Hz. The new facility is designed to operate at lower voltages (20 - 200 kv), lower impedance (50 - 75 Ohm), ... |
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| ESPA: EELV Secondary Payload Adapter With Whole-Spacecraft Isolation for Primary and Secondary Payloads |
MAR 2000 |
12 pages |
| Authors:
Joseph R. Maly; Paul S. Wilke; Emily C. Fowler; S. A. Haskett; Dino Sciulli; T. E. Meink; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
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| 640 X 486 Long-Wavelength Two-Color GaAs/AlGaAs Quantum Well Infrared Photodetector (QWIP) Focal Plane Array Camera |
13 JAN 2000 |
10 pages |
| Authors:
S. D. Gunapala; S. V. Bandara; A. Singh; J. K. Liu; S. B. Rafol; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| We have designed and fabricated an optimized long-wavelength/very- long-wavelength two-color quantum well infrared photodetector (QWIP) device structure. The device structure was grown on a 3-in semi- insulating GaAs substrate by molecular beam epitaxy (MBE) . The wafer was processed into several 640 x 486 format monolithically integrated 8-9 and 14-15 micrometers two-color (or dual wavelength) QWIP focal plane arrays (FPA's). These FPA's were then hybridized to 640 x 486 silicon ... |
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| Cesium iodide cathodes for high-power microwave devices. |
JUL 1999 |
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| Authors:
R. J. Umstattd; D. A. Shiffler; M. D. Haworth; K. J. Hendricks; J. W. Luginsland; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A variety of cesium iodide-coated carbon fiber cathodes have been designed and tested for high voltage (300 - 500 kV), high current operation. Here, we describe the conditioning process and present the most recent experimental data for a thin annular beam test diode. During these reproducible microsecond-duration pulses, this diode exhibits promising beam impedance maintainability and gap closure speeds of less than 0.4 cm/microsecond(s) ec. Also presented are recent results ... |
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| Simulation of electron transport in liquids under high electric fields. |
JUL 1999 |
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| Authors:
J. M. Lehr; E. E. Kunhardt; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| High Power Impulse generation depends strongly on both the voltage and the rate of voltage rise which is applied to the radiating structure. Thus, placing the peaking switch at the apex of the antenna optimizes the transient radiating system. Liquids are prime candidates for the peaking switch media because of their high dielectric strength and its compatibility with lensing structures. Copyright 2002 SPIE--The International Society for Optical Engineering. |
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| MEMBRANE MIRROR CHARACTERISTICS USED WITH REAL TIME HOLOGRAPHY, |
JUN 1999 |
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| Authors:
Richard A. Carreras; Dan K. Marker; James M. Wilkes; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
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| (U) THIS PAPER GIVES A CURSORY DESCRIPTION OF THE RESEARCH BEING PERFORMED AT THE AIR FORCE RESEARCH LABORATORY IN THE FIELDS OF MEMBRANE MIRRORS AND REAL TIME HOLOGRAPHY. THE PAPER SHOWS A SHAPE MODIFICATION METHOD FOR THE MEMBRANE MIRROR ACHIEVED THROUGH ENFORCED BOUNDARY DISPLACEMENTS BY WHICH THE MEMBRANCE MIRROR SHAPE MODIFICATION RESULTED IN MOVING THE INFLATED MEMBRANE SHAPE TOWARD A DESIRED OPTICAL PROFILE. MINIMIZATION OF THE OPTICAL FIGURE ERROR IS ... |
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| Membrane Mirror Characteristics for used with Real Time Holography |
1999 |
10 pages |
| Authors:
Richard A. Carreras; Dan K. Marker; James M. Wilkes; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| Space-based inflatable technology is of current interest to NASA DoD and in particular to the Air Force Research Laboratory. Potentially large gains in lowering launch costs through reductions in structural mass and volume are driving this activity. Diverse groups are researching and developing this technology for radio and radar antennas, optical telescopes and solar power and propulsion applications. Regardless of the use, one common requirement for successful application is the ... |
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| Air Force Research Laboratory Spacecraft Cryocooler Endurance EvaluationUpdate: FY98-99 |
1999 |
8 pages |
| Authors:
B. J. Tomlinson; C. Yoneshige; N. Abhyankar; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The need for long term endurance evaluation data on space cryocoolers has long been an issue due to the 10-year plus design life of this technology and the absence of any accepted accelerated testing methodology. The Air Force Research Laboratory (AFRL), under sponsorship from the Ballistic Missile Defense Organization (BMDO), has been evaluating the long term performance of space cryocooler technology for the past five years to ... |
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| Magnetically Tuned Wide-Band Quantum Well Infrared Photodetectors |
08 JAN 1998 |
10 pages |
| Authors:
Danhong Huang; S. K. Lyo; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The electron eigenstates of double quantum well system in an in-plane magnetic field are calculated accurately using the density-functional theory, which includes the Coulomb interaction between electrons. The absorption coefficient as a function of the probe photon energy is further calculated using the self-consistent-field theory, which takes into account many-body effects on the optical intersubband transitions. The dependence of the absorption spectra on the magnetic field, temperature, electron density, well ... |
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| Battlefield Optical Surveillance System (BOSS) - A HMMWV Mounted System for Non-Lethal Point Defense |
1998 |
9 pages |
| Authors:
W. T. Cooley; Trevor Davis; John Kelly; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| As the United States Armed Forces are increasingly asked to control world conflict through humanitarian and peacekeeping missions, non-lethal alternatives for applying force have spurred technologist to identify new methods for engaging potential adversaries. One promising technology comes from advancements in high power (1 to 10 watts) semiconductor lasers, lead by the United States Air Force Research Laboratory, Phillips Research Site. Semiconductor lasers have ... |
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| Optically Pumped Mid-IR Vibrational Hydrogen Chloride Laser |
1998 |
30 pages |
| Authors:
Harold C. Miller; John McCord; Gordon D. Hager; Steven J. Davis; William J. Kessler; David B. Oakes; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The results of an experimental investigation of an optically pumped vibrational laser in HCl are reported. Two different excitation sources were used: a Nd:YAG laser pumped optical parametric oscillator and a Raman shifted alexandrite laser. Overtone pumping on the (2,0) and (3,0) bands was employed to produce laser oscillation on the (3,2) and (2,1) bands near 3.8 microns. We also developed a model for the optically pumped laser and compare ... |
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| Experimental Studies of Explosively-Driven Magnetohydrodynamic Generators |
OCT 1997 |
41 pages |
| Authors:
F. J. Agee; G. Baca; D. Chama; F. M. Lehr; T. Englert; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| The field of High Power Microwaves (HPM) has evolved as a result of advances in the field of pulsed power, which has made pulses of electrical energy available that can drive HPM sources to gigawatt levels. One of the most compact forms of pulsed power involves the storage of chemical energy in the form of explosive charges. Explosive magnetohydrodynamic (MHD) generators are electrical power sources, which convert the kinetic energy ... |
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| Observation of Quantum-Confined Stark Effect in Triple-Coupled InGaAs/ GaAs/AlGaAs Quantum Well Infrared Photodetector |
AUG 1997 |
15 pages |
| Authors:
Sheng S. Li; J. C. Chiang; A. Singh; M. Z. Tidrow; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| We have investigated the quantum-confined Stark effect (QCSE) in several n-type InGaAs/GaAs/AlGaAs triple-coupled quantum well infrared photodetectors (TC-QWIPs) for 8-12 micrometers long wavelength infrared (LWIR) detection. The basic structure of this TC-QWIP consists of three coupled quantum wells (QWs) formed by a Si-doped In(x)Ga(1-x)As QW and two undoped thin GaAs QWs separated by two thin Al(y)Ga(1-y)As barriers. Three TC-QWIP devices with varying indium and aluminum compositions were fabricated and characterized. ... |
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| X-Ray Measurements With Films Masked by Staggered Absorption Layers of Aluminum |
JAN 1997 |
35 pages |
| Authors:
Thad J. Englert; Sue E. Englert; James H. Degnan; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A technique for measuring x-ray emissions within the photon energy range 1 keV to 10 keV is described. A staggered set of aluminum absorbers, supported by kimfoil, is used to mask x-ray-sensitive film. Response functions of aluminum and kimfoil absorbers, along with the response function of the film, provide reasonable energy discrimination. Integrated incident energy along with modest spectral resolution may be obtained by convolution of the transmission of x-rays ... |
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