Matthew Decamp - Academia.edu (original) (raw)

Papers by Matthew Decamp

ABSTRACT Traditional time-domain terahertz (THz) spectroscopy techniques require the combination ... more ABSTRACT Traditional time-domain terahertz (THz) spectroscopy techniques require the combination of sub-picosecond laser systems and time-delay stages for spectral analysis, making the design of a portable THz spectrometer challenging. In this work, we demonstrate an alternative method of spectrally resolving coherent THz radiation using narrow band optical light and passive optical spectrum analyzers. This method utilizes THz induced electro-optic modulation of a narrow band laser to upconvert the spectral content of the THz radiation to the visible portion of the electro-magnetic spectrum. This device does not require any movable parts and is well suited for spectrally analyzing both broadband and narrowband THz radiation. The spectral resolution of this technique is limited by the bandwidth of the optical radiation and the non-linear medium. Further advancements will include the development of a portable THz spectrometer, suitable for either research or clinical applications.

$Research paper thumbnail of Thermal and laser induced sintering in Pt nanoparticles studied by conventional and synchrotron x-ray diffraction$

Bulletin of the American Physical Society, Mar 5, 2015

ABSTRACT Time-resolved x-ray diffraction has become a very powerful tool in the study of structur... more ABSTRACT Time-resolved x-ray diffraction has become a very powerful tool in the study of structural dynamics of solids. The wave nature of x-rays allows the detection of milliÅngstrom changes in crystalline structure. Coupling the sensitivity of x-ray scattering with ultrafast pump-probe techniques can provide unprecedented studies of ultrafast dynamics in solids. This chapter demonstrates how time-resolved x-ray diffraction can be used to view transient strains in crystalline solids. Several different x-ray scattering geometries are explored.

Radiation Physics and Chemistry, 2004

... J. Chem. Phys., 104 (1996), pp. 10001–10007. Chin 1999 A. Chin, RW Schoenlein, TE Glover, P. ... more ... J. Chem. Phys., 104 (1996), pp. 10001–10007. Chin 1999 A. Chin, RW Schoenlein, TE Glover, P. Balling, WP Leemans and CV Shank, Ultrafast structural dynamics in InSb probed by time-resolved X-ray diffraction. Phys. Rev. Lett., 83 2 (1999), pp. 336–339. ...

$Research paper thumbnail of Femtosecond X-ray diffraction: Experiments and limits$

X-Ray Fel Optics and Instrumentation, 2001

Femtosecond x-ray diffraction: experiments and limits. [Proceedings of SPIE 4143, 26 (2001)]. Jus... more Femtosecond x-ray diffraction: experiments and limits. [Proceedings of SPIE 4143, 26 (2001)]. Justin S. Wark, AM Allen, PC Ansbro, Philip H. Bucksbaum, Zenghu Chang, Mark F. DeCamp, Roger W. Falcone, Philip A. Heimann ...

Physical Review B, 2005

A series of nondegenerate pump-probe measurements were carried out on a DNA-wrapped single-walled... more A series of nondegenerate pump-probe measurements were carried out on a DNA-wrapped single-walled carbon nanotube ͑SWNT͒ sample that is enriched with the ͑6,5͒ species. The pump pulse excites SWNTs at ϳ1.567 eV, which corresponds to an energy of two D-band phonons above the excitonic band edge of the ͑6,5͒ SWNT. The dynamics of different channels of exciton relaxation for the ͑6,5͒ SWNT is analyzed in terms of the decay in the time-resolved differential transmission spectra. By systematically varying the values of the probe energy, E probe , to be in and out of resonance with the minority ͑n , m͒ SWNT species in the sample at different pump fluence levels, an intermediate decay component associated with a hot phonon-absorption process is studied in detail. When the values of E probe were further tuned to off-resonance positions, photoinduced absorption processes could be investigated.

$Research paper thumbnail of Seeing sound: Dynamical effects in ultrafast x-ray diffraction$

Abstract Time-resolved x-ray diffraction has become a very powerful tool in the study of structur... more Abstract Time-resolved x-ray diffraction has become a very powerful tool in the study of structural dynamics of solids. The wave nature of x-rays allows the detection of milliAngstrom changes in crystalline structure. Coupling the sensitivity of x-ray scattering with ultrafast ...

Physical Review B, Nov 15, 2005

Understanding the different channels of relaxation for optically excited electrons in one-dimensi... more Understanding the different channels of relaxation for optically excited electrons in one-dimensional systems has played a crucial role in developing potential applications for optoelectronic devices in nanoscale systems. As a prototype one-dimensional 1D material, single-walled carbon nanotubes SWNTs and their optical properties have been a subject of intense study.

Springer Series in Chemical Physics, 2005

ABSTRACT We study amide I vibrational solvation dynamics of N-methylacetamide in D2O, CDCl3, and ... more ABSTRACT We study amide I vibrational solvation dynamics of N-methylacetamide in D2O, CDCl3, and DMSO-d6. Three pulse photon echo and 2D-IR measurements characterize the frequency correlation function, which reflects fluctuating electric fields acting on the vibration.

Journal of the Optical Society of America B, 2014

ABSTRACT We demonstrate coherence measurements of single-photon-level collective excitations of v... more ABSTRACT We demonstrate coherence measurements of single-photon-level collective excitations of vibrational states using transient coherent spontaneous Raman scattering in liquid methanol. We observe the decay of the 1033 cm−1 mode and coherence oscillations due to simultaneous excitation of the 2834 and 2944 cm−1 modes. The coherence life-times and oscillation frequencies agree with frequency-domain line-shape measurements and femtosecond coherent anti-Stokes Raman scattering measurements. The demonstrated technique is complementary to and, in some cases, simpler than traditional stimulated spectroscopy techniques in that it does not require more than one laser and is free of nonresonant background.

The journal of physical chemistry. B, Jan 2, 2005

The vibrational frequency of the amide I transition of peptides is known to be sensitive to the s... more The vibrational frequency of the amide I transition of peptides is known to be sensitive to the strength of its hydrogen bonding interactions. In an effort to account for interactions with hydrogen bonding solvents in terms of electrostatics, we study the vibrational dynamics of the amide I coordinate of N-methylacetamide in prototypical polar solvents: D2O, CDCl3, and DMSO-d6. These three solvents have varying hydrogen bonding strengths, and provide three distinct solvent environments for the amide group. The frequency-frequency correlation function, the orientational correlation function, and the vibrational relaxation rate of the amide I vibration in each solvent are retrieved by using three-pulse vibrational photon echoes, two-dimensional infrared spectroscopy, and pump-probe spectroscopy. Direct comparisons are made to molecular dynamics simulations. We find good quantitative agreement between the experimentally retrieved and simulated correlation functions over all time scales...

2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, 2006

ABSTRACT A new method of acquiring two-dimensional correlation spectra in a single-shot is presen... more ABSTRACT A new method of acquiring two-dimensional correlation spectra in a single-shot is presented. As a demonstration of the functionality of this spectrometer, the two-dimensional correlation spectrum of atomic rubidium is measured.

CLEO: 2014, 2014

ABSTRACT We demonstrate the measurement of vibrational state coherence dynamics in liquid methano... more ABSTRACT We demonstrate the measurement of vibrational state coherence dynamics in liquid methanol using transient coherent spontaneous Raman scattering. The resulting lifetimes and quantum beat frequency agree with frequency-domain and coherent anti-Stokes Raman scattering measurements.

2008 Conference on Lasers and Electro-Optics, 2008

1. Introduction: Molecules bridge the gap between laser-atom physics and that of small scale soli... more 1. Introduction: Molecules bridge the gap between laser-atom physics and that of small scale solids like clusters. The complex nature of the molecule gives rise to collective effects like field alignment, enhanced ionization, dissociation, and Coulomb explosion [1,2]. When a ...