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Physics

Optical physics and communications

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Displaying 601 - 625 of 853

Spectral response of an upconversion detector and spectrometer

September 17, 2013
Author(s)
Paulina S. Kuo, Oliver T. Slattery, Yong-Su Kim, Jason S. Pelc, M. M. Fejer, Xiao Tang
We theoretically and experimentally investigate the spectral response of an upconversion detector and discuss implications for its use as an infrared spectrometer. Upconversion detection is based on high-conversion-efficiency sum-frequency generation (SFG)

Generalized Tabletop EUV Coherent Diffractive Imaging in a Transmission Geometry

September 11, 2013
Author(s)
Justin M. Shaw, Bosheng Zhang, Matthew Seaberg, Daniel Adams, Dennis Gardner, Elizabeth Shanblatt, Henry C. Kapteyn, Margaret M. Murnane
We demonstrate the first generalized tabletop EUV coherent microscope that can image extended, non-isolated, non-periodic, objects. By implementing keyhole coherent diffraction imaging with curved mirrors and a tabletop high harmonic source, we demonstrate

Pneumatically Actuated and Kinematically Positioned Optics Mounts

September 4, 2013
Author(s)
Roger C. Brown, Steven Olmschenk, Wu Saijun, Ari Dyckovsky, Robert Wyllie, James V. Porto
We present two complementary designs of pneumatically actuated and kinematically positioned optics mounts: one designed for vertical mounting and translation, the other designed for horizontal mounting and translation. The design and measured stability

The Cosmic Infrared Background Experiment (CIBER): the Narrow Band Spectrometer

August 19, 2013
Author(s)
Steven W. Brown, Keith R. Lykke, Allan W. Smith, P M. Korngut, T. Renbarger, T. Arai, J. Battle, A. Cooray, V. Hristov, B. Keating, M. G. Kims, A. Lanz, D. H. Lee, L. R. Levenson, P. Mason, T. Matsumoto, S. Matsuura, U. W. Niam, B. Shultz, I. Sullivan, K. Tsumura, T. Wada, M. Zemcov
We have developed a near-infrared spectrometer designed to measure the absolute intensity of the Solar 854.2 nm Ca II Fraunhofer line, scattered by interplanetary dust, in the Zodiacal light spectrum. Based on the known equivalent line width in the Solar

Hybrid quantum-well system for wavelength-channel selection

June 28, 2013
Author(s)
Lu Deng, Edward W. Hagley, Chengjie Zhu
We consider a hybrid quantum-well structure consisting of regions whose properties alternate between active Raman gain and electromagnetically induced transparency. We present both analytical and numerical results that indicate a large light beam defection

The impact of turbulence on high accuracy time-frequency transfer across free space

June 26, 2013
Author(s)
Laura C. Sinclair, Fabrizio R. Giorgetta, William C. Swann, Esther Baumann, Ian R. Coddington, Nathan R. Newbury
Atmospheric optical path-length variations are measured across a 2-km optical link through a frequency comb-based system with femtosecond-level precision. Without mitigation, the turbulent piston effect will severely restrict time-frequency transfer from

Harnessing 3D Scattered Optical Fields for sub-20 nm Defect Detection

June 24, 2013
Author(s)
Bryan M. Barnes, Martin Y. Sohn, Francois R. Goasmat, Hui Zhou, Richard M. Silver, Abraham Arceo
Experimental imaging at =193 nm of sub-resolved defects performed at several focus positions yields a volume of spatial and intensity data. Defects are located in a differential volume, given a reference, with up to 5x increase in sensitivity.

A comb-calibrated FMCW LADAR for absolute distance measurements

June 15, 2013
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Ian R. Coddington, Laura C. Sinclair, Kevin O. Knabe, William C. Swann, Nathan R. Newbury
We present a comb calibrated frequency-modulated continuous wave (FMCW) LADAR system for absolute distance measurements to diffuse or specular surfaces. The FMCW LADAR uses a MEMS-based external cavity laser that is swept quasi-sinusoidally over 1 THz at a

Nanosecond-scale timing jitter in transition edge sensors at telecom and visible wavelengths

June 10, 2013
Author(s)
Antia A. Lamas-Linares, Brice R. Calkins, Nathan A. Tomlin, Thomas Gerrits, Adriana Lita, Joern Beyer, Richard Mirin, Sae Woo Nam
Transition edge sensors (TES) have the highest reported efficiencies (> 98%) for single photon detection in the visible and near infrared. Experiments in quantum information and foundations of physics that rely on this efficiency have started incorporating

Free-space optical time-frequency transfer over 2 km

June 9, 2013
Author(s)
William C. Swann, Fabrizio R. Giorgetta, Laura C. Sinclair, Esther Baumann, Ian R. Coddington, Nathan R. Newbury
Precision free-space time-frequency transfer could advance fields where present microwave-based transfer is inadequate. We demonstrate an optical free-space link with femtosecond timing deviation and residual instability below 10 −18 at 1000 seconds.

X-Ray Micro-Beam Diffraction Determination of Full Stress Tensors in Cu TSVs

May 28, 2013
Author(s)
Chukwudi A. Okoro, Lyle E. Levine, Oleg A. Kirillov, Yaw S. Obeng, Ruqing Xu, Jonathan Z. Tischler, Wenjun Liu, Klaus Hummler
We report the first non-destructive, depth resolved determination of the full stress tensor in Cu through-silicon vias (TSVs), using synchrotron based micro-beam X-ray diffraction. Two adjacent Cu TSVs were studied; one deliberately capped with SiO2, the

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
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