Papers by Jefferson Odhner
Proceedings of SPIE, Jul 27, 2016
Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases re... more Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM “red bends more”) than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.
This paper presents an overview of Coming IntelliSense's 3D electromagnetic MEMS mirror tech... more This paper presents an overview of Coming IntelliSense's 3D electromagnetic MEMS mirror technology for use in optical switching applications. This work presents for the first time a dense array of mirrors actuated through large angles at low voltage and low current. Multiple coils on the backs of the mirrors interact with permanent magnetic fields to provide actuation. Unlike previous electromagnetic 2-axis mirrors, a novel and simple arrangement of coils and magnets provides true 2-axis orthogonal actuation, as well as an order of magnitude increase in tilt (°/mA). Actuation is linear vs. drive current on both axes, and displays negligible charging and drift. These mirrors have achieved greater than 10 degrees mechanical rotation per mA in each axis, a 40x increase over previously reported work. The mirror rotation angle is hysteresis free to less than 0.01 degrees, and is actuated at about 1 volt.
Proceedings of SPIE, Apr 12, 1988
A universal hologram construction layout, which takes advantage of the resonant coherent modes of... more A universal hologram construction layout, which takes advantage of the resonant coherent modes of a laser, is described. A master transmission hologram made with this layout can be used to make transmission, reflection, or rainbow copies with a minimum amount of component movement between exposures of each type of hologram. This saves much of the set-up time normally involved between exposures, thus reducing the cost of each hologram. The theory of resonant axial coherence modes explains how different object and reference beam lengths can still result in bright, efficient holograms.
Proceedings of SPIE, Oct 3, 2000
The ability to create stable holographic grating is an important part of the production of many t... more The ability to create stable holographic grating is an important part of the production of many telecommunication products. The stability problem is increased by the need to use ultra-violet light for close fringe spacing and long exposure times on phot-resist - a relatively low sensitivity material. Active fringe locking increases the modulation depth and efficiency of these holographic gratings. A discussion of how fringe lockers work and how they can be incorporated into a manufacturing set-up is followed by results of using fringe lockers in the manufacturing of some telecommunication devices.
Proceedings of SPIE, Mar 24, 2000
A novel approach to characterizing integrated optical waveguides is described in which laser ligh... more A novel approach to characterizing integrated optical waveguides is described in which laser light illuminates the surface normal of the waveguide substrate and the transmitted light observed in the far field uniquely describes a number of physical characteristics of the waveguide. The proof of concept has been demonstrated with a HeNe laser on an ion diffused waveguide in silica glass but the technique is applicable to any integrated otpical waveguide. The advantages of this approach are that it is a great deal less expensive than conventional approaches using a Nemarski microscope or an EDAX attachment to an electron microscope and is very simple to set up. The small index variations that comprise a waveguide on a substrate are normally invisible . However, using this technique, when laser light is scanned across the waveguide, a unique pattern is seen in the far field that can be interpreted to not only determine the location of the waveguide, a unique pattern is seen in the far field that can be interpreted to not only determine the location of the waveguides but also certain physical characteristics about them.
Proceedings of SPIE, Sep 13, 2007
BAE Systems presents the results of a program to model the performance of Raman LIDAR systems for... more BAE Systems presents the results of a program to model the performance of Raman LIDAR systems for the remote detection of atmospheric gases, air polluting hydrocarbons, chemical and biological weapons, and other molecular species of interest. Our model, which integrates remote Raman spectroscopy, 2D and 3D LADAR, and USAF atmospheric propagation codes permits accurate determination of the performance of a Raman LIDAR system. The very high predictive performance accuracy of our model is due to the very accurate calculation of the differential scattering cross section for the specie of interest at user selected wavelengths. We show excellent correlation of our calculated cross section data, used in our model, with experimental data obtained from both laboratory measurements and the published literature. In addition, the use of standard USAF atmospheric models provides very accurate determination of the atmospheric extinction at both the excitation and Raman shifted wavelengths.
Proceedings of SPIE, Oct 13, 2005
BAE SYSTEMS reports on a program to develop a high-fidelity model and simulation to predict the p... more BAE SYSTEMS reports on a program to develop a high-fidelity model and simulation to predict the performance of angle-angle-range 3D flash LADAR Imaging Sensor systems. 3D Flash LADAR is the latest evolution of laser radar systems and provides unique capability in its ability to provide high-resolution LADAR imagery upon a single laser pulse; rather than constructing an image from multiple
A fiber optic interrogator has been developed with software (SAV) that will detect people walking... more A fiber optic interrogator has been developed with software (SAV) that will detect people walking, vehicles and digging across a 100 m swath around a buried fiber optic cable. These activities cause minute pressure waves that transmit through the ground to the buried fiber. The pressure waves then hit the fiber causing minute changes in the fiber index. Rayleigh backscattering is extremely sensitive to these index changes. The three activities are distinguished from each other with SAV and the activities can be located within a few meters along the fiber. The temporal frequency of this backscatter allows discrimination of the targets. The resultant system is analogous to an array of geophones where the number and sensitivity of the geophones is programmable. The interrogator was field tested with 40 Km of buried fiber providing definitive discrimination of all three target types. This system was designed for maximum versatility with SAV controlled variable pulse width to improve target location, SAV controlled variable pulse rate and data sampling to optimize storage requirements, and SAV controlled variable output power to allow increased sensitivity at longer ranges. The buried fiber GPS coordinates are correlated with Google maps to allow the events to be overlaid onto a topographical map. The result is a color coded real time pictorial of events over the entire fiber length (>80 Km) fused with a map of the area giving operators total situational awareness. The entire interrogator and processing computer have been packaged into a portable ruggedized 19” rack. Data is transmitted across an Ethernet connection for analysis at a central location. This system is suitable for use on any border. For the US Northern border: There are only 2,200 U.S. agents (4 agents/10 Km average). For the U.S. Southern border: there are 17,659 US agents (56 agents/10 Km average). The Hyperbox® would reduce the number of required agents by providing a force multiplier with a few dozen installations and 24/7 coverage at a price that is the lowest cost/Km of any other available surveillance technology.
Proceedings of SPIE, Jan 9, 2004
BAE SYSTEMS reports on a program to characterize the performance of MEMS corner cube retroreflect... more BAE SYSTEMS reports on a program to characterize the performance of MEMS corner cube retroreflector arrays under laser illumination. These arrays have significant military and commercial application in the areas of: 1) target identification; 2) target tracking; 3) target location; 4) identification friend-or-foe (IFF); 5) parcel tracking, and; 6) search and rescue assistance. BAE SYSTEMS has theoretically determined the feasibility of these devices to learn if sufficient signal-to-noise performance exists to permit a cooperative laser radar sensor to be considered for device location and interrogation. Results indicate that modest power-apertures are required to achieve SNR performance consistent with high probability of detection and low false alarm rates.
An optical polyspectral sensor has been developed and tested which calculates the magnitude and d... more An optical polyspectral sensor has been developed and tested which calculates the magnitude and directional velocity of an incoming projectile to queue a reactive countermeasure. This paper describes the sensor modeling, sensitivity analysis, and experimental results of a sensor consisting of four sheets of light. Sensor application could be extended to all projectiles that present a measurable laser radar cross section to the sensor.
L'invention concerne un element a surface courbe, par exemple une ampoule electrique (16), un... more L'invention concerne un element a surface courbe, par exemple une ampoule electrique (16), un ornement ou un conducteur de lumiere, dont au moins une partie sur sa surface interieure ou exterieure (20) est couverte d'un reseau de diffraction, par exemple un reseau de diffraction holographique ou un reseau de diffraction mecanique, ce reseau de diffraction diffractant une lumiere pour emettre une couleur pour l'observateur. Le reseau de diffraction peut prendre la forme d'un element optique holographique (HOE) fixe a la surface courbe ou d'un motif optique holographique (HOP) marque en relief sur la surface courbe.
Lidar Remote Sensing for Environmental Monitoring VIII, 2007
BAE Systems presents the results of a program to model the performance of Raman LIDAR systems for... more BAE Systems presents the results of a program to model the performance of Raman LIDAR systems for the remote detection of atmospheric gases, air polluting hydrocarbons, chemical and biological weapons, and other molecular species of interest. Our model, which integrates remote Raman spectroscopy, 2D and 3D LADAR, and USAF atmospheric propagation codes permits accurate determination of the performance of a Raman LIDAR system. The very high predictive performance accuracy of our model is due to the very accurate calculation of the differential scattering cross section for the specie of interest at user selected wavelengths. We show excellent correlation of our calculated cross section data, used in our model, with experimental data obtained from both laboratory measurements and the published literature. In addition, the use of standard USAF atmospheric models provides very accurate determination of the atmospheric extinction at both the excitation and Raman shifted wavelengths.
SPIE Proceedings, 2005
An optical polyspectral sensor has been developed and tested which calculates the magnitude and d... more An optical polyspectral sensor has been developed and tested which calculates the magnitude and directional velocity of an incoming projectile to queue a reactive countermeasure. This paper describes the sensor modeling, sensitivity analysis, and ...
Electro-Optical Remote Sensing, 2005
BAE SYSTEMS has developed a Low Cost Targeting System (LCTS) consisting of a FLIR for target dete... more BAE SYSTEMS has developed a Low Cost Targeting System (LCTS) consisting of a FLIR for target detection, laser-illuminated, gated imaging for target identification, laser rangefinder and designator, GPS positioning, and auto-tracking capability within a small compact system size. This system has proven its ability to acquire targets, range and identify these targets, and designate or provide precise geo-location coordinates to
The Sixteenth Annual International Conference on Micro Electro Mechanical Systems, 2003. MEMS-03 Kyoto. IEEE
This paper presents an overview of Coming IntelliSense's 3D electromagnetic MEMS mirror tech... more This paper presents an overview of Coming IntelliSense's 3D electromagnetic MEMS mirror technology for use in optical switching applications. This work presents for the first time a dense array of mirrors actuated through large angles at low voltage and low current. Multiple coils on the backs of the mirrors interact with permanent magnetic fields to provide actuation. Unlike previous electromagnetic 2-axis mirrors, a novel and simple arrangement of coils and magnets provides true 2-axis orthogonal actuation, as well as an order of magnitude increase in tilt (°/mA). Actuation is linear vs. drive current on both axes, and displays negligible charging and drift. These mirrors have achieved greater than 10 degrees mechanical rotation per mA in each axis, a 40x increase over previously reported work. The mirror rotation angle is hysteresis free to less than 0.01 degrees, and is actuated at about 1 volt.
Advanced Free-Space Optical Communications Techniques and Technologies, 2004
BAE SYSTEMS reports on a program to characterize the performance of MEMS corner cube retroreflect... more BAE SYSTEMS reports on a program to characterize the performance of MEMS corner cube retroreflector arrays under laser illumination. These arrays have significant military and commercial application in the areas of: 1) target identification; 2) target tracking; 3) target location; 4) identification friend-or-foe (IFF); 5) parcel tracking, and; 6) search and rescue assistance. BAE SYSTEMS has theoretically determined the feasibility of these devices to learn if sufficient signal-to-noise performance exists to permit a cooperative laser radar sensor to be considered for device location and interrogation. Results indicate that modest power-apertures are required to achieve SNR performance consistent with high probability of detection and low false alarm rates.
Journal of Microelectromechanical Systems, 2004
This paper presents an electromagnetic MEMS mirror technology for use in 3-D optical switching ap... more This paper presents an electromagnetic MEMS mirror technology for use in 3-D optical switching applications. These mirrors may be actuated through large angles at low voltage and low current. Multiple coils on the backs of the mirrors interact with permanent magnetic fields to provide two-axis orthogonal actuation. A custom package brings the MEMS mirror array and magnets into close proximity. Actuation is linear versus drive current on both axes, and displays negligible charging and drift. These mirrors have achieved greater than 10 mechanical rotation per mA in each axis. The mirror rotation angle is hysteresis free to less than the 0 01 measurement accuracy.
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Papers by Jefferson Odhner