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Displaying 626 - 650 of 861

All-angle negative refraction and active flat lensing of ultraviolet light

May 22, 2013
Author(s)
Ting Xu, Amit Agrawal, Maxim Abashin, Kenneth J. Chau, Henri Lezec
The ability of a left-handed medium to sustain backwards electromagnetic waves leads to counter-intuitive phenomena such as negative refraction. We report the experimental implementation of a three-dimensional negative-index metamaterial operating at an

Modulated photocurrent spectroscopy of CdTe/CdS solar cells-equivalent circuit analysis

May 20, 2013
Author(s)
Behrang H. Hamadani, John F. Roller, Kounavis Panagiotis, Nikolai B. Zhitenev, David J. Gundlach
We have used the technique of photocurrent modulated spectroscopy to investigate the dynamic response of charge carrier transport in thin film CdTe/CdS solar cells as a function of light bias and temperature over a broad excitation frequency range. The

Random testing reveals excessive power in commercial laser pointers

May 1, 2013
Author(s)
Joshua A. Hadler, Edna L. Tobares, Marla L. Dowell
In random testing of 122 commercial laser pointers, we observed that 89.7 % of green pointers and 44.4 % of red pointers were not in compliance with the Code of Federal Regulations, producing laser power in excess of the Accessible Emission Limit at one or

Intercomparison between optical and x-ray scatterometry measurements of FinFET structures

April 8, 2013
Author(s)
Paul Lemaillet, Thomas Germer, Regis J. Kline, Daniel Sunday, Chengqing C. Wang, Wen-Li Wu
In this paper, we present a comparison of profile measurements of vertical field effect transistor (FinFET) fin arrays by optical critical dimension (OCD) metrology and critical dimension small angle X-ray scattering (CD-SAXS) metrology. Spectroscopic

Accurate, inexpensive testing of handheld lasers for safe use and operation

March 7, 2013
Author(s)
Marla L. Dowell, Joshua A. Hadler
An accurate, inexpensive test bed for measurements of optical power emitted from handheld lasers is described. Our test bed consists of a thermopile detector, bandpass optical filters, an adjustable iris, and self-centering holders for mounting of the

Effect of atomic coherence on "temporal cloaking" in atomic vapors

February 27, 2013
Author(s)
Runbing Li, Lu Deng, Edward W. Hagley, Joshua C. Bienfang, M G. Payne, Mo-Lin Ge
We discuss a different scheme to achieve temporal cloaking in warm atomic vapors. Instead of creating a temporal-spatial window in a patched broadband short optical pulse using static differential dispersion of an optical fiber, we create a temporal

Experimental test of an event-based corpuscular model modification as an alternative to quantum mechanics

February 13, 2013
Author(s)
Giorgio Brida, Ivo P. Degiovanni, Marco Genovese, Alan L. Migdall, Fabrizio Piacentini, Sergey Polyakov, Paola Traina
We present the first experimental test that distinguishes between an event-based corpus- cular model of the interaction of photons with matter and quantum mechanics. The test looks at the interference that results as a single photon passes through a Mach

Experimental test of an event-based corpuscular model modification as an alternative to quantum mechanics

February 13, 2013
Author(s)
Giorgio Brida, Ivo P. Degiovanni, Marco Genovese, Alan L. Migdall, Fabrizio Piacentini, Sergey Polyakov, Paola Traina
We present the first experimental test that distinguishes between an Event-Based Corpuscular Model (EBCM)9) of the interaction of photons with matter and quantum mechanics. The test looks at the interference that results as a single photon passes through a

Absolute spectroscopy of N2O near 4.5 um with a comb-calibrated, frequency-swept quantum cascade laser spectrometer

January 14, 2013
Author(s)
Kevin O. Knabe, Paul A. Williams, Fabrizio R. Giorgetta, Michael Radunsky, Chris Armacost, Sam Crivello, Nathan R. Newbury
We present absolute line center frequencies for 24 fundamental nu-3 ro-vibrational P-branch transitions near 4.5 um in N2O with an absolute frequency uncertainty of 800 kHz. The spectra were acquired with a swept laser spectrometer consisting of an

Experimental demonstration of a receiver beating the standard quantum limit for multiple nonorthogonal coherent-state discrimination

January 6, 2013
Author(s)
Francisco E. Becerra Chavez, Jingyun Fan, Gerald Baumgartner, Julius Goldhar, Jonathan Kosloski, Alan L. Migdall
The measurement of the state of a quantum system with inherent quantum uncertainty (noise) approaching the ultimate physical limits is of both technological and fundamental interest. Quantum noise prevents any mutually nonorthogonal quantum states, such as

Ultrafast element-specific magnetization Dynamics of complex magnetic materials on a table-top

December 21, 2012
Author(s)
Thomas J. Silva, Justin M. Shaw, Hans T. Nembach, Chan La-O-Vorakiat, Henry C. Kapteyn, Margaret M. Murnane, Stefan Mathias, Roman Adam, Patrik Grychtol, Martin Aeschlimann, Claus M. Schneider, Emrah Turgut, Dennis Rudolf
We review recent progress in femtosecond magnetization dynamics probed by extreme ultraviolet pulses from high-harmonic generation. In a transverse magneto-optical Kerr geometry, we establish an ultrafast, element-specific experimental capability - on a

Application of nanoporous silicon substrates for terahertz spectroscopy

December 20, 2012
Author(s)
Edwin J. Heilweil, Shu-Zee A. Lo, Gagan Kumar, Thomas E. Murphy
Infrared spectroscopy is a valuable tool for probing and characterizing the macro-molecular motions of complex molecules, including vibrational and phonon modes that cannot be easily accessed through visible spectroscopy. We describe here an improved

Adaptive measurements in nonorthogonal state discrimination

December 18, 2012
Author(s)
Francisco E. Becerra Chavez, Alan L. Migdall
Adaptive measurements represent important resources in quantum information science and quan- tum technologies. They take advantage of the knowledge of partial measurements of the system to optimize subsequent measurements and perform tasks that are dicult

Remote sensing of chiral signatures on Mars

November 1, 2012
Author(s)
William Sparks, James H. Hough, Thomas Germer, Frank Robb, Ludmilla Kolokolova
We describe circular polarization as a remote sensing diagnostic of chiral signatures which may be applied to Mars. The remarkable phenomenon of homochirality provides a unique biosignature which can be amenable to remote sensing through circular

Slot-mode-coupled optomechanical crystals

October 22, 2012
Author(s)
Marcelo I. Davanco, Jasper Chan, Amir H. Safavi-Naeini, Oskar Painter, Kartik A. Srinivasan
We design a cavity optomechanical system in which a localized GHz frequency mechanical mode of a nanobeam resonator is evanescently coupled to a high quality factor (Q > 10^6) optical mode of a separate nanobeam optical cavity. Using separate nanobeams

Broadband Emissivity Calibration of Highly Reflective Samples at Cryogenic Temperatures

October 15, 2012
Author(s)
Solomon I. Woods, Timothy M. Jung, Greg Ly, Simon G. Kaplan, Jie Yu
We have developed a technique for calibrating the broadband optical emissivity of high reflectivity samples at cryogenic temperatures. This measurement method employs a primary standard optical detector with high absorptance from visible wavelengths to

Quasianalytical modal approach for computing Casimir interactions in periodic nanostructures

October 3, 2012
Author(s)
Francesco Intravaia, Paul S. Davids, Ricardo Decca, Vladimir Aksyuk, Daniel Lopez, Diego A. Dalvit
We present an almost fully analytical technique for computing Casimir interactions between 1D periodic lamellar gratings based on a modal approach. Our method improves on previous work on Casimir modal approaches for nanostructures by using the exact form

Extending single-photon optimized superconducting transition edge sensors beyond the single-photon counting regime

October 2, 2012
Author(s)
Thomas Gerrits, Brice R. Calkins, Nathan A. Tomlin, Adriana E. Lita, Alan L. Migdall, Richard P. Mirin, Sae Woo Nam
Typically, transition edge sensors resolve photon number of up to 10 or 20 photons, depending on the wavelength and TES design. We extend that dynamic range up to 1000 photons, while maintaining sub- shot noise detection process uncertainty of the number

Upper roughness limitations on the TIS/RMS relationship

September 27, 2012
Author(s)
J C. Stover, Sven Schroeder, Thomas Germer
The relationship between total integrated scatter (TIS) and root mean square (rms) roughness was developed in the radar literature and enabled the first use of scatter measurements to monitor optical roughness. This relationship has been used and misused
Displaying 626 - 650 of 861
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