scholarly journals Resonant generation of coherent phonons in a superconductor by ultrafast optical pump pulses

2011 ◽  
Vol 84 (21) ◽  
Author(s):  
Andreas P. Schnyder ◽  
Dirk Manske ◽  
Adolfo Avella
Keyword(s):  
Optical Pump ◽  
Ultrafast Optical ◽  
Coherent Phonons ◽  
Resonant Generation

Ultrafast optical-pump terahertz-probe spectroscopy of individual silicon nanowires

CLEO: 2013 ◽  
2013 ◽  
Author(s):  
Taeyong Kim ◽  
Sangwan Sim ◽  
Jungmok Seo ◽  
Jaehong Lee ◽  
Heetak Han ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Optical Pump ◽  
Ultrafast Optical ◽  
Probe Spectroscopy

scholarly journals Understanding Multiferroic Hexagonal Manganites by Static and Ultrafast Optical Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Ting Wang ◽  
Chih Wei Luo ◽  
Takayoshi Kobayashi
Keyword(s):  
Electronic Structure ◽  
Magnetic Ordering ◽  
Optical Pump ◽  
Pump Probe ◽  
Spin Lattice ◽  
Ultrafast Optical ◽  
Ultrafast Optical Spectroscopy ◽  
Hexagonal Manganites ◽  
Spin Charge Coupling ◽  
Probe Spectroscopy

Multiferroic hexagonal manganites ReMnO3studied by optics are reviewed. Their electronic structures were revealed by static linear and nonlinear spectra. Two transitions located at~1.7 eV and~2.3 eV have been observed and attributed to the interband transitions from the lower-lying Mn3+dxy/dx2-y2anddxz/dyzstates to the Mn3+d3z2-r2state, respectively. These so-called d-d transitions exhibit a blueshift as decreasing temperatures and an extra blueshift nearTN. This dramatic change indicates that the magnetic ordering seriously influences the electronic structure. On the other hand, the ultrafast optical pump-probe spectroscopy has provided the important information on spin-charge coupling and spin-lattice coupling. Because of the strongly correlation between electronic structure and magnetic ordering, the amplitude of the initial rising component inΔR/Rshows striking changes at the vicinity ofTN. Moreover, the coherent optical and acoustic phonons were observed on optical pump-probe spectroscopy. Both the amplitude and dephasing time of coherent phonons also exhibit significant changes atTN, which provide the evidence for spin-lattice interaction in these intriguing materials.

Adiabatic-following solutions for multisubband quantum wells excited by an ultrafast optical pump field

1992 ◽  
Vol 45 (20) ◽  
pp. 11918-11928 ◽  
Author(s):  
Leung Tsang ◽  
Chaiyuth Chansungsan ◽  
Shun L. Chuang
Keyword(s):  
Quantum Wells ◽  
Pump Field ◽  
Optical Pump ◽  
Ultrafast Optical

scholarly journals Measurement of Ultrafast Carrier Dynamics in Epitaxial Graphene

2008 ◽  
Vol 1081 ◽  
Author(s):  
Jahan M. Dawlaty ◽  
Shriram Shivaraman ◽  
Mvs Chandrashekhar ◽  
Michael G. Spencer ◽  
Farhan Rana
Keyword(s):  
Relaxation Times ◽  
Epitaxial Graphene ◽  
Optical Pump ◽  
Carrier Relaxation ◽  
Pump Probe ◽  
Graphene Layers ◽  
Ultrafast Optical ◽  
Interband Scattering ◽  
Ultrafast Carrier ◽  
Probe Spectroscopy

ABSTRACTUsing ultrafast optical pump-probe spectroscopy, we have measured carrier relaxation times in epitaxial graphene layers grown on SiC wafers. We find two distinct time scales associated with the relaxation of nonequilibrium photogenerated carriers. An initial fast relaxation transient in the 70-120 fs range is followed by a slower relaxation process in the 0.4-1.7 ps range. The slower relaxation time is found to be inversely proportional to the degree of crystalline disorder in the graphene layers as measured by Raman spectroscopy. We relate the measured fast and slow time constants to carrier-carrier and carrier-phonon intraband and interband scattering processes in graphene.

scholarly journals Tunable GaAs metasurfaces for ultrafast image processing

2021 ◽  
Vol 2015 (1) ◽  
pp. 012057
Author(s):  
Viacheslav Iushkov ◽  
Alexander Shorokhov ◽  
Andrey Fedyanin
Keyword(s):  
Image Processing ◽  
Optical Switching ◽  
Optical Pumping ◽  
Relaxation Times ◽  
Optical Computing ◽  
Fused Silica ◽  
Optical Pump ◽  
Pump Probe ◽  
Ultrafast Optical ◽  
Ultrafast Switching

Abstract The design and construction of optical semiconductor metasurfaces for various applications have become an important topic in the last decade. However, most metasurfaces are static; they are optimized for only one exact purpose and typically realize only one operation. In this work, we discuss the basic methods for creating dynamic metasurfaces giving special attention to ultrafast optical switching and provide numerical modeling of metasurfaces made of GaAs material realizing different amplitude-phase profiles under asymmetrical optical pumping. The metasurfaces are composed of semiconductor discs immersed in a fused silica medium. We demonstrate that based on Fourier transform and spatial filtering methods, these structures can be used for image processing and optical computing. Ultrafast switching is achieved by using an optical pump-probe scheme. The characteristic relaxation times between the pumped state and the relaxed state are on the order of several picoseconds.

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