Characterization of ultrafast interactions with materials through the direct measurement of the optical phase

1996 ◽  
Author(s):  
Tracy S. Clement ◽  
George Rodriguez ◽  
W. M. Wood ◽  
Antoinette J. Taylor
Keyword(s):  
Direct Measurement ◽  
Optical Phase

scholarly journals Densified Pupil Spectrograph as High-precision Radial Velocimetry: From Direct Measurement of the Universe’s Expansion History to Characterization of Nearby Habitable Planet Candidates

2022 ◽  
Vol 163 (2) ◽  
pp. 63
Author(s):  
Taro Matsuo ◽  
Thomas P. Greene ◽  
Mahdi Qezlou ◽  
Simeon Bird ◽  
Kiyotomo Ichiki ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Direct Measurement ◽  
High Precision ◽  
Resolving Power ◽  
Line Of Sight ◽  
High Dispersion ◽  
Velocity Measurements ◽  
Habitable Planet ◽  
Airy Disk

Abstract The direct measurement of the universe’s expansion history and the search for terrestrial planets in habitable zones around solar-type stars require extremely high-precision radial-velocity measures over a decade. This study proposes an approach for enabling high-precision radial-velocity measurements from space. The concept presents a combination of a high-dispersion densified pupil spectrograph and a novel line-of-sight monitor for telescopes. The precision of the radial-velocity measurements is determined by combining the spectrophotometric accuracy and the quality of the absorption lines in the recorded spectrum. Therefore, a highly dispersive densified pupil spectrograph proposed to perform stable spectroscopy can be utilized for high-precision radial-velocity measures. A concept involving the telescope’s line-of-sight monitor is developed to minimize the change of the telescope’s line of sight over a decade. This monitor allows the precise measurement of long-term telescope drift without any significant impact on the Airy disk when the densified pupil spectra are recorded. We analytically derive the uncertainty of the radial-velocity measurements, which is caused by the residual offset of the lines of sight at two epochs. We find that the error could be reduced down to approximately 1 cm s−1, and the precision will be limited by another factor (e.g., wavelength calibration uncertainty). A combination of the high-precision spectrophotometry and the high spectral resolving power could open a new path toward the characterization of nearby non-transiting habitable planet candidates orbiting late-type stars. We present two simple and compact highly dispersed densified pupil spectrograph designs for cosmology and exoplanet sciences.

Further characterization of iodide-induced hyperthyroidism based on the direct measurement of intrathyroidal iodine stores

1992 ◽  
Vol 13 (2) ◽  
pp. 114-118
Author(s):  
M. H. JONCKHEER ◽  
B. VELKENIERS ◽  
L. VANHAELST ◽  
VAN M. BLERK
Keyword(s):  
Direct Measurement

Optical Phase Characterization of Photonic Integrated Devices

2014 ◽  
Vol 20 (4) ◽  
pp. 417-421 ◽  
Author(s):  
Joaquin Matres ◽  
Guillem C. Ballesteros ◽  
Sara Mas ◽  
Antoine Brimont ◽  
Pablo Sanchis ◽  
...  
Keyword(s):  
Optical Phase ◽  
Integrated Devices ◽  
Phase Characterization

Phase-Resolved Fluorescence Spectral and Lifetime Characterization of Commercial Humic Substances

1997 ◽  
Vol 51 (7) ◽  
pp. 921-929 ◽  
Author(s):  
Sherry L. Hemmingsen ◽  
Linda B. McGown
Keyword(s):  
Steady State ◽  
Humic Substances ◽  
Direct Measurement ◽  
Fluorescence Lifetime ◽  
Spectral Features ◽  
Good Precision ◽  
Convenient Means ◽  
Accurate Comparison ◽  
Excitation Emission Matrices

Phase-resolved excitation-emission matrices (PREEMs) are shown to provide a unique visual representation of the intrinsic fluorescence properties of humic acids under a variety of solution conditions. The calculation of spectral peak ratios in PREEMs as well as steady-state excitation-emission matrices provides a convenient means for quantitating differences between the spectra with good precision. Absorbance correction is shown to be essential for accurate comparison among spectral features. Increased detail is available from PREEMs at various modulation frequencies that reveal the distribution of fluorescence lifetime contributions across the spectral surface. Direct measurement of fluorescence lifetime recovered three ranges of lifetime components in the humic substances, <1 ns, 2–5 ns, and 8–14 ns, that are consistent with previously reported lifetimes. PREEMs, which provide a concise “survey” of how the lifetimes change across the spectrum, may aid in pinpointing spectral regions that provide the best lifetime discrimination among samples.

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