Dr. Edwin P. Walker Profile

Dr. Edwin P. Walker

at Boeing LTS Inc

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Author

Publications (17)

Proceedings Article | 26 August 2008 Paper

Progress in two-photon 3D optical data storage

Ed Walker, Alexander Dvornikov, Ken Coblentz, Peter Rentzepis

Proceedings Volume 7053, 705308 (2008) https://doi.org/10.1117/12.798814

KEYWORDS: Molecules, Absorption, Semiconductor lasers, Luminescence, Objectives, Optical storage, Rhodamine, Lithium, 3D optical data storage, Confocal microscopy

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Proceedings Article | 11 July 2007 Paper

253GB recorded in two-photon 3D disk

Ed Walker, Alexander Dvornikov, Ken Coblentz, Sadik Esener, Peter Rentzepis

Proceedings Volume 6620, 66200A (2007) https://doi.org/10.1117/12.751962

KEYWORDS: Objectives, Lithium, Confocal microscopy, Microscopes, Liquids, Silver, Optical storage, Polymers, Dysprosium, 3D optical data storage

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Proceedings Article | 20 September 2006 Paper

Studies of new nondestructive read-out media for two-photon 3D high-density storage

A. Dvornikov, E. Walker, P. Rentzepis

Proceedings Volume 6331, 63310E (2006) https://doi.org/10.1117/12.678648

KEYWORDS: Molecules, Absorption, Luminescence, Composites, Nondestructive evaluation, Data storage, Molecular spectroscopy, Optical storage, Rhodamine B, Spectroscopy

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Proceedings Article | 17 June 2004 Paper

Towards ultrahigh-density multilayer disk recording by two-photon absorption

Yi Zhang, Alexandr Dvornikov, Yoshi Taketomi, Edwin Walker, Peter Rentzepis, Sadik Esener

Proceedings Volume 5362, (2004) https://doi.org/10.1117/12.543253

KEYWORDS: Objectives, Luminescence, Absorption, Microscopes, Pulsed laser operation, Molecules, Photons, Confocal microscopy, Molecular lasers, Point spread functions

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Advances in healthcare imaging products and multimedia entertainment systems are demanding higher media capacity (TB/disk) and faster data transfer speeds (lGb/s) from future removable disk based data storage systems. One promising direction to satisfy these requirements with low cost systems is the use of optical volumetric multi-layer disk media. At Call/Recall we have demonstrated the scalability of two-photon recordable photochromic doped polymeric Write Once Read Many (WORM) disk media to more than 1 00 layers with negligible interlayer crosstalk and excellent stability of the written bits"2'3'4'5'6. The media employed in our WORM system, consist ofphotochromic organic molecules designed and synthesized so that they change their structure, upon excitation at the absorption band of the molecule5'7'8'9'. A spot is written in the volume of the medium only at points of temporal and spatial intersection of two photons with sufficient energy to record by altering the structure of the photochromic molecule. A high power short pulse laser beam is tightly focused for recording. Recording occurs only within a small volume around the focus of the laser beam due to twophoton absorption. The recording response ofthe material follows the square ofthe optical system point spread ftinction (PSF) resulting in a recorded bit size that is 30% less than the Rayleigh criterion PSF. The recorded bits are read by fluorescence when excited by suitable optical radiation absorbed within the written spot volume. The doped polymer media is low cost, flexibly shaped and molded, and its properties may be customized (by changing the dopant molecules) to match evolving application and technology requirements. We had previously reported bit dimensions of 0.5 x0.5x4.5jim 2 withNA 0.75 and 532nm wavelength exhibiting raw bit-error rates (BER) of iO'. Here we show a ftjrther decrease in the bit size to 0.4 x 0.4 x 2jtm with a higher NA1 .4 objective lens at 532nm wavelength, resulting in ultra high density volumetric disk recording using up to 100 layers and providing a potential for 400bits4im2 "effective area! density". This paper discusses the theory and approach as well as experimental results we used and obtained to demonstrate the feasibility of high NA recording of volumetric multilayer disks by two photon absorption.

Proceedings Article | 16 September 2003 Paper

Characterization of photochromic bit-wise volumetric storage media for space applications

Yan Zhang, John Butz, Jason Curtis, Neil Beaudry, Warren Bletscher, James Erwin, Dak Knight, Thomas Milster, Edwin Walker

Proceedings Volume 5069, (2003) https://doi.org/10.1117/12.533090

KEYWORDS: Optical storage, Ions, Molecules, Luminescence, Absorption, Satellites, Particles, Radiation effects, Data storage, Charge-coupled devices

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Proceedings Article | 16 September 2003 Paper

Novel method for tracking in homogeneous volumetric media

Timothy Miller, John Butz, Thomas Milster, Warren Bletscher, Edwin Walker, Sang-Ki Park, David Felix

Proceedings Volume 5069, (2003) https://doi.org/10.1117/12.533072

KEYWORDS: Actuators, Diffractive optical elements, Optical tracking, Objectives, Prototyping, Photoresist materials, Servomechanisms, Optical storage, Control systems, Optical design

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Proceedings Article | 1 July 2003 Paper

Present performance and future directions in two-photon addressed write once read many (WORM) volumetric optical disk storage systems

Sadik Esener, Edwin Walker, Yi Zhang, Alexander Dvornikov, Peter Rentzepis

Proceedings Volume 4988, (2003) https://doi.org/10.1117/12.501105

KEYWORDS: Luminescence, Objectives, Optical storage, Detector arrays, Sensors, CMOS sensors, Molecules, Data storage, Absorption, Semiconductor lasers

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Proceedings Article | 23 January 2002 Paper

Top illuminator design for 2D parallel readout in a 3D multilayer optical data storage system

Wenyi Feng, Edwin Walker, Haichuan Zhang, Yi Zhang, Alexander Dvornikov, Sadik Esener

Proceedings Volume 4459, (2002) https://doi.org/10.1117/12.454038

KEYWORDS: Data storage, Servomechanisms, Monochromatic aberrations, Optical storage, Vertical cavity surface emitting lasers, 3D optical data storage, Luminescence, Aspheric lenses, Microlens array, Axicons

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Proceedings Article | 10 January 2002 Paper

Spherical aberration correction for two-photon recorded monolithic multilayer optical data storage

Edwin Walker, Jacques Duparre, Haichuan Zhang, Wenyi Feng, Yi Zhang, Alexander Dvornikov

Proceedings Volume 4342, (2002) https://doi.org/10.1117/12.453405

KEYWORDS: Monochromatic aberrations, Optical storage, Objectives, Telescopes, Luminescence, Microscopes, Refraction, Adaptive optics, Lens design, Video

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Proceedings Article | 30 October 2001 Paper

Beam shaping for optical data storage

Edwin Walker, Tomas Milster

Proceedings Volume 4443, (2001) https://doi.org/10.1117/12.446739

KEYWORDS: Electronic filtering, Optical filters, Spatial frequencies, Data storage, Sensors, Interference (communication), Objectives, X band, Optical storage, Signal to noise ratio

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Proceedings Article | 30 October 2001 Paper

Beam shaping for a high-power vertical cavity surface emitting laser

Edwin Walker, Tomas Milster

Proceedings Volume 4443, (2001) https://doi.org/10.1117/12.446741

KEYWORDS: Vertical cavity surface emitting lasers, Axicons, High power lasers, Data storage, Mirrors, Beam shaping, Continuous wave operation, Gallium arsenide, CCD cameras, Objectives

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Proceedings Article | 18 September 2000 Paper

Single-beam two-photon-recorded monolithic multilayer optical disks

Haichuan Zhang, Alexander Dvornikov, Edwin Walker, Nam-Hyong Kim, Frederick McCormick

Proceedings Volume 4090, (2000) https://doi.org/10.1117/12.399355

KEYWORDS: Luminescence, Optical discs, Absorption, Interference (communication), Signal to noise ratio, Sensors, Signal detection, Optical amplifiers, Objectives, Pulsed laser operation

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Proceedings Article | 18 September 2000 Paper

Servo error signal generation for two-photon-recorded monolithic multilayer optical data storage

Edwin Walker, Xuezhe Zheng, Frederick McCormick, Haichuan Zhang, Nam-Hyong Kim, Joannes Costa, Alexander Dvornikov

Proceedings Volume 4090, (2000) https://doi.org/10.1117/12.399356

KEYWORDS: Sensors, Servomechanisms, Signal detection, Signal generators, Actuators, Electronics, Optical storage, Beam splitters, Luminescence, Objectives

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Proceedings Article | 24 May 2000 Paper

Two-photon 3D optical data storage disk recording and readout

Haichuan Zhang, Edwin Walker, Alexander Dvornikov, Nam-Hyong Kim, Joannes Costa, Frederick McCormick

Proceedings Volume 4089, (2000) https://doi.org/10.1117/12.386815

KEYWORDS: Luminescence, 3D optical data storage, Absorption, Data storage, Sensors, Spatial light modulators, Objectives, Signal detection, Laser systems engineering, Modulation

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Proceedings Article | 22 November 1999 Paper

Parallel access 3D multilayer optical storage using 2-photon recording

Frederick McCormick, Haichuan Zhang, Alexander Dvornikov, Edwin Walker, Curtis Chapman, Nam-Hyong Kim, Joannes Costa, Sadik Esener, Peter Rentzepis

Proceedings Volume 3802, (1999) https://doi.org/10.1117/12.370231

KEYWORDS: Optical storage, Sensors, 3D optical data storage, Luminescence, Servomechanisms, Data storage, Magnetism, Absorption, Signal processing, Signal to noise ratio

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Proceedings Article | 8 September 1995 Paper

Superresolution by optical and electronic filtering

Edwin Walker, Tomas Milster

Proceedings Volume 2514, (1995) https://doi.org/10.1117/12.218711

KEYWORDS: Electronic filtering, Optical filters, Super resolution, Data storage, Magneto-optics, Interference (communication), Objectives, Relays, Modulation, Servomechanisms

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Proceedings Article | 22 April 1993 Paper

Figures of merit for laser beam quality

Tomas Milster, Edwin Walker

Proceedings Volume 1834, (1993) https://doi.org/10.1117/12.143841

KEYWORDS: Monochromatic aberrations, Wavefronts, Diffraction, Laser energy, CCD cameras, Spherical lenses, Sensors, Optical testing, Quality measurement, Beam quality measurement

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Showing 5 of 17 publications

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