Dr. Gregory J. Exarhos Profile

Dr. Gregory J. Exarhos

Lab Fellow and Associate Director at Pacific Northwest National Lab

SPIE Involvement:

Editor | Author

Publications (25)

Proceedings Article | 16 December 2004 Paper

In situ Raman probe for chemical agents using ultraporous substrates

Charles Windisch, Yongsoon Shin, Gregory Exarhos

Proceedings Volume 5585, (2004) https://doi.org/10.1117/12.572006

KEYWORDS: Raman spectroscopy, Adsorption, Surface enhanced Raman spectroscopy, Particles, Metals, Gold, Molecules, Silica, Sensors, Data modeling

Read Abstract +

Proceedings Article | 6 July 2004 Paper

Optical limiting by index-matched phase-segregated mixtures

Gregory Exarhos, Kim Ferris

Proceedings Volume 5359, (2004) https://doi.org/10.1117/12.516442

KEYWORDS: Light scattering, Particles, Refractive index, Scattering, Nonlinear filtering, Composites, Nonlinear optics, Optical spheres, Optical limiting, Polymers

Read Abstract +

Proceedings Article | 10 June 2004 Paper

Heterogeneous mixtures as NLO Christiansen filters for optical limiting

Gregory Exarhos, Kim Ferris, William Samuels

Proceedings Volume 5273, (2004) https://doi.org/10.1117/12.524443

KEYWORDS: Light scattering, Particles, Scattering, Refractive index, Polymers, Composites, Nonlinear filtering, Optical spheres, Nonlinear optics, Optical limiting

Read Abstract +

Proceedings Article | 10 October 2003 Paper

Chopping of near- and mid-infrared radiation using a curled electrostatic MEMS actuator

David Dausch, Scott Goodwin, Gregory Exarhos

Proceedings Volume 5074, (2003) https://doi.org/10.1117/12.488786

KEYWORDS: Actuators, Signal detection, Sensors, Electrodes, Infrared detectors, Pyroelectric detectors, Infrared radiation, Mid-IR, Staring arrays, Microelectromechanical systems

Read Abstract +

Proceedings Article | 30 May 2003 Paper

Optical limiting based on liquid-liquid immiscibility

Gregory Exarhos, Kim Ferris, William Samuels, Robert Owings

Proceedings Volume 4932, (2003) https://doi.org/10.1117/12.473580

KEYWORDS: Scattering, Liquids, Optical limiting, Light scattering, Nonlinear optics, Optical spheres, Refractive index, Particles, Optical filters, Nonlinear filtering

Read Abstract +

Proceedings Article | 9 April 2002 Paper

Evaluation of materials selection criteria for composite optical limiters

Kim Ferris, Charles Windisch, Theresa Marmolejo, Gregory Exarhos

Proceedings Volume 4679, (2002) https://doi.org/10.1117/12.461697

KEYWORDS: Refractive index, Molecules, Composites, Polarizability, Nonlinear optics, Systems modeling, Optical limiting, Performance modeling, Polymers, Carbon

Read Abstract +

Proceedings Article | 16 July 2001 Paper

High-contrast artificial eyelid for protection of optical sensors

Scott Goodwin-Johansson, Mark Davidson, Gregory Exarhos, Paul Holloway, Gary McGuire, Robert Cozzens, Robert Schwartz

Proceedings Volume 4329, (2001) https://doi.org/10.1117/12.432674

KEYWORDS: Electrodes, Actuators, Camera shutters, Optical sensors, Gold, Microelectromechanical systems, Reflectivity, Electromagnetism, Optical fabrication equipment, Metals

Read Abstract +

Proceedings Article | 12 April 2001 Paper

Index-mismatch scattering approach to optical limiting

Gregory Exarhos, Kim Ferris, Charles Windisch, Brian Bozlee, Steven Risser, Simone van Swam

Proceedings Volume 4347, (2001) https://doi.org/10.1117/12.425012

KEYWORDS: Transmittance, Optical limiting, Refractive index, Nonlinear optics, Particles, Scattering, Iodine, Light scattering, Laser scattering, Refraction

Read Abstract +

Proceedings Article | 7 June 2000 Paper

Artificial eyelid for protection of optical sensors

Scott Goodwin-Johansson, Paul Holloway, Gary McGuire, Leonard Buckley, Robert Cozzens, Robert Schwartz, Gregory Exarhos

Proceedings Volume 3987, (2000) https://doi.org/10.1117/12.387781

KEYWORDS: Actuators, Electrodes, Metals, Camera shutters, Polymers, Gold, Optical sensors, Microelectromechanical systems, Reflectivity, Dielectrics

Read Abstract +

Proceedings Article | 3 March 2000 Paper

Linear and nonlinear contributions on the dielectric response of zirconia and polyethylene films

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 3902, (2000) https://doi.org/10.1117/12.379330

KEYWORDS: Dielectrics, Zirconium dioxide, Nonlinear optics, Chemical elements, Dielectric polarization, Solids, Modulation, Composites, Laser applications, Laser induced damage

Read Abstract +

Proceedings Article | 7 April 1999 Paper

Spectroscopic studies of pulsed-laser-induced damage sites in heated CaF2 crystals

Brian Bozlee, Gregory Exarhos, Randy Teel

Proceedings Volume 3578, (1999) https://doi.org/10.1117/12.344449

KEYWORDS: Crystals, Raman spectroscopy, Calcium, Absorption, Crystallography, Laser crystals, Pulsed laser operation, Particles, Laser damage threshold, Laser induced damage

Read Abstract +

Based upon previous studies of temperature dependent defect state formation in high energy alpha particle irradiated CaF₂ analogous temperature dependent effects were expected to occur when heated crystals were exposed to Q- switching emission from a pulsed Nd:YAG laser. It was shown in the (alpha) -irradiation work that optimum clustering of calcium atoms to form colloids would occur at a critical temperature. In recent work irradiation of isothermally heated crystals at fluences on the order of 1 J/cm² produced both catastrophic mechanical damage to the crystal as well as localized defect states within the lattice. Below 200 degrees C the mechanical damage was severe, as evidenced by extensive fractures radiating from the damage center along the crystal cleavage planes. However, above 200 degrees C, these fracture lines revealed the presence of CaF₂ lattice forbidden bands associated with calcium colloids in addition to a blue shift of the principal T_2g CaF₂ mode frequency. The T_2g line shift signifies the presence of compressive stress in the CaF₂ lattice induced by the presence of the calcium colloids. Forbidden phonon line intensities varied with Raman probe wavelength, and the associated Raman excitation profile followed the wavelength response of the optical absorption band at 580 nm, which is ascribed to colloid resonance absorption. The presence of colloid was detected at all temperatures, and the extent of colloid formation was found to be only weakly dependent upon the crystal temperature. This lack of sensitivity may be ascribed to highly located heating of the crystal surface during the laser pulse, which could supersede the effect of ambient temperature. Pulsed Raman studies of thin CaF₂ section sat laser fluences just below the damage thresholds did indeed indicate temperature excursions within the laser footprint. For samples held at temperatures above 200 degrees C, the color centers were found to absorb more strongly in the 400-500 nm and NIR regions, Probably indicating greater aggregation of F centers in the crystal.

Proceedings Article | 7 April 1999 Paper

Time-evolved optical properties of liquid crystalline molecules

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 3578, (1999) https://doi.org/10.1117/12.344443

KEYWORDS: Molecules, Optical properties, Crystals, Liquid crystals, Liquids, Complex systems, Absorption, LCDs, Statistical modeling, Nonlinear response

Read Abstract +

Proceedings Article | 20 April 1998 Paper

Microstructural size effects on the dielectric response of inhomogeneous media

Kim Ferris, Larry Chick, Gregory Exarhos, Steven Risser

Proceedings Volume 3244, (1998) https://doi.org/10.1117/12.307009

KEYWORDS: Dielectrics, Aluminum

Read Abstract +

Proceedings Article | 20 April 1998 Paper

Pulsed laser irridation of isothermally heated titania films

Gregory Exarhos, Aimee Rose, Karen Schielke

Proceedings Volume 3244, (1998) https://doi.org/10.1117/12.307004

KEYWORDS: Pulsed laser operation, Temperature metrology, Silica, Sol-gels, Nd:YAG lasers, Q switching, Transmittance, Optical testing, Raman spectroscopy, Titanium dioxide

Read Abstract +

Proceedings Article | 13 May 1997 Paper

Microstructural and dielectric susceptibility effects on predictions of dielectric properties

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 2966, (1997) https://doi.org/10.1117/12.274236

KEYWORDS: Dielectrics, Composites, Dielectric polarization, 3D modeling, Chemical elements, Systems modeling, Finite element methods, Polarizability, Optical components, Coating

Read Abstract +

Proceedings Article | 13 May 1997 Paper

cw laser compaction of aqueous-solution-deposited metal oxide films

Gregory Exarhos, Tasshi Dennis

Proceedings Volume 2966, (1997) https://doi.org/10.1117/12.274284

KEYWORDS: Metals, Laser irradiation, Crystals, Coating, Oxides, Water, Annealing, Continuous wave operation, Luminescence, Silicon

Read Abstract +

Proceedings Article | 27 May 1996 Paper

Inclusion and overlayer effects on the electric fields in dielectric films

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 2714, (1996) https://doi.org/10.1117/12.240385

KEYWORDS: Dielectrics, Optical alignment, Interfaces, Natural surfaces, Glasses, Chemical elements, Laser induced damage, Dielectric polarization, Fabrication, Physics

Read Abstract +

Proceedings Article | 14 July 1995 Paper

Enhancement factors for local electric fields in inhomogeneous media

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 2428, (1995) https://doi.org/10.1117/12.213724

KEYWORDS: Dielectrics, Optical coatings, 3D modeling, Carbon, Chemical vapor deposition, Finite-difference time-domain method, Laser induced damage, Sol-gels, Standards development, Dielectric polarization

Read Abstract +

Proceedings Article | 28 July 1994 Paper

Distributions of local electric fields in inhomogeneous media

Kim Ferris, Gregory Exarhos, Steven Risser

Proceedings Volume 2114, (1994) https://doi.org/10.1117/12.180930

KEYWORDS: Chemical elements, Dielectrics, Dielectric polarization, Statistical modeling, Chemical species, Physics, Maxwell's equations, Deposition processes, Numerical analysis, Statistical analysis

Read Abstract +

Proceedings Article | 28 July 1994 Paper

Optical characterization of dielectric films and modified surfaces

Gregory Exarhos

Proceedings Volume 2114, (1994) https://doi.org/10.1117/12.180877

KEYWORDS: Crystals, Raman spectroscopy, Optical coatings, Dielectrics, Laser induced damage, Laser irradiation, Temperature metrology, Laser beam diagnostics, Light scattering, Thin films

Read Abstract +

Proceedings Article | 24 June 1993 Paper

Atomic force microscopy of laser-conditioned and laser-damaged amorphous TiO2 sol-gel thin films

Nancy Hess, Gregory Exarhos, Martin Iedema

Proceedings Volume 1848, (1993) https://doi.org/10.1117/12.147403

KEYWORDS: Refractive index, Crystals, Silicon films, Raman spectroscopy, Sol-gels, Atomic force microscopy, Laser crystals, Laser induced damage, Laser damage threshold, Optical properties

Read Abstract +

Proceedings Article | 24 June 1993 Paper

Surface morphology, phase characterization, and stability of solution-deposited zirconia films

Gregory Exarhos, Nancy Hess, Susanne Wood

Proceedings Volume 1848, (1993) https://doi.org/10.1117/12.147407

KEYWORDS: Zirconium dioxide, Crystals, Raman spectroscopy, Laser induced damage, Luminescence, Silica, Laser crystals, Metals, Annealing, Laser irradiation

Read Abstract +

Proceedings Article | 29 July 1992 Paper

Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Gregory Exarhos, Nancy Hess, Susanne Wood

Proceedings Volume 1624, (1992) https://doi.org/10.1117/12.60094

KEYWORDS: Crystals, Laser crystals, Laser irradiation, Sol-gels

Read Abstract +

Proceedings Article | 1 June 1991 Paper

Laser Raman measurements of dielectric coatings as a function of temperature

Gregory Exarhos, Nancy Hess, Samantha Ryan

Proceedings Volume 1441, (1991) https://doi.org/10.1117/12.27529

KEYWORDS: Crystals, Raman spectroscopy, Temperature metrology, Silica, Laser induced damage, Sol-gels, Chemical species, Thin films, Laser crystals, Glasses

Read Abstract +

Proceedings Article | 1 November 1990 Paper

Optical properties and laser damage measurements of inorganic polymer films

Gregory Exarhos

Proceedings Volume 1438, 14380X (1990) https://doi.org/10.1117/12.2294442

Read Abstract +

Showing 5 of 25 publications

Proceedings Volume Editor (21)

SPIE Conference Volume | 30 March 2018

Laser-Induced Damage in Optical Materials 2017

SPIE Conference Volume | 28 February 2017

Laser-Induced Damage in Optical Materials 2016

SPIE Conference Volume | 31 March 2016

Laser-Induced Damage in Optical Materials: 2015

SPIE Conference Volume | 18 December 2014

Laser-Induced Damage in Optical Materials: 2014

SPIE Conference Volume | 2 December 2013

Laser-Induced Damage in Optical Materials: 2013

Showing 5 of 21 publications

Conference Committee Involvement (39)

Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference

24 September 2018 | Boulder, Colorado, United States

Laser-Induced Damage in Optical Materials 2017

24 September 2017 | Boulder, Colorado, United States

Laser-Induced Damage in Optical Materials 2016

25 September 2016 | Boulder, Colorado, United States

Laser-Induced Damage in Optical Materials: 2015

28 September 2015 | Boulder, Colorado, United States

SPIE Laser Damage

27 September 2015 | Boulder, United States

Laser-Induced Damage in Optical Materials: 2014

15 September 2014 | Boulder, Colorado, United States

Laser Damage Symposium: XLV Annual Symposium on Optical Materials for High-Power Lasers

22 September 2013 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices X

27 August 2013 | San Diego, California, United States

Laser Damage Symposium XLIV: Annual Symposium on Optical Materials for High Power Lasers

23 September 2012 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices IX

14 August 2012 | San Diego, California, United States

Laser Damage Symposium XLIII: Annual Symposium on Optical Materials for High Power Lasers

18 September 2011 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices VIII

23 August 2011 | San Diego, California, United States

Laser Damage Symposium XLII: Annual Symposium on Optical Materials for High Power Lasers

26 September 2010 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices VII

3 August 2010 | San Diego, California, United States

Laser Damage Symposium XLI: Annual Symposium on Optical Materials for High Power Lasers

21 September 2009 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices VI

4 August 2009 | San Diego, California, United States

Boulder Damage Symposium XL: Annual Symposium on Optical Materials for High Power Lasers

22 September 2008 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices V

13 August 2008 | San Diego, California, United States

Boulder Damage Symposium XXXIX: Annual Symposium on Optical Materials for High Power Lasers

24 September 2007 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices IV

27 August 2007 | San Diego, California, United States

Boulder Damage Symposium XXXVIII: Annual Symposium on Optical Materials for High Power Lasers

26 September 2006 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices III

15 August 2006 | San Diego, California, United States

Boulder Damage Symposium XXXVII: Annual Symposium on Optical Materials for High Power Lasers

19 September 2005 | Boulder, CO, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices II

3 August 2005 | San Diego, California, United States

Boulder Damage Symposium XXXVI

20 September 2004 | Boulder, Colorado, United States

Nanoengineering: Fabrication, Properties, Optics, and Devices

4 August 2004 | Denver, Colorado, United States

XXXIV Annual Symposium on Optical Materials for High Power Lasers: Boulder Damage Symposium

22 September 2003 | Boulder, Colorado, United States

Nanofabrication Technologies

3 August 2003 | San Diego, California, United States

Laser-Induced Damage in Optical Materials: 2002 and 7th International Workshop on Laser Beam and Optics Characterization

16 September 2002 | Boulder, CO, United States

Boulder Damage 2001

1 October 2001 | Boulder, CO, United States

Laser-Induced Damage in Optical Materials

16 October 2000 | Boulder, CO, United States

Laser-Induced Damage in Optical Materials: 2000

16 October 2000 | Boulder, United States

Nonlinear Optical Materials

1 November 1999 | Bellevue, WA, United States

Laser-Induced Damage in Optical Materials: 1999

4 October 1999 | Boulder, CO, United States

Laser-Induced Damage in Optical Materials: 1999

4 October 1999 | Boulder, United States

Laser-Induced Damage in Optical Materials: 1998

28 September 1998 | Boulder, CO, United States

Laser-Induced Damage in Optical Materials: 1998

28 September 1998 | Boulder, United States

Laser-Induced Damage in Optical Materials: 1997

6 October 1997 | Boulder, CO, United States

Laser-Induced Damage in Optical Materials: 1997

6 October 1997 | Boulder, United States

Showing 5 of 39 Conference Committees

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years