Pump-Probe Measurements Using Silicon Nanocrystal Waveguides

2003 ◽  
Vol 770 ◽  
Author(s):  
Nathanael Smith ◽  
Max J. Lederer ◽  
Marek Samoc ◽  
Barry Luther-Davies ◽  
Robert G. Elliman
Keyword(s):  
Probe Beam ◽  
Time Resolution ◽  
Pump Beam ◽  
Silicon Nanocrystals ◽  
Continuous Wave ◽  
Optical Gain ◽  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
Probe Measurements

AbstractOptical pump-probe measurements were performed on planar slab waveguides containing silicon nanocrystals in an attempt to measure optical gain from photo-excited silicon nanocrystals. Two experiments were performed, one with a continuous-wave probe beam and a pulsed pump beam, giving a time resolution of approximately 25 ns, and the other with a pulsed pump and probe beam, giving a time resolution of approximately 10 ps. In both cases the intensity of the probe beam was found to be attenuated by the pump beam, with the attenuation increasing monotonically with increasing pump power. Time-resolved measurements using the first experimental arrangement showed that the probe signal recovered its initial intensity on a time scale of 45-70 μs, a value comparable to the exciton lifetime in Si nanocrystals. These data are shown to be consistent with an induced absorption process such as confined carrier absorption. No evidence for optical gain was observed.

scholarly journals Time-resolved polarimetry for photoexcited QP dynamics in Bi2212

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542031
Author(s):  
K. Watanabe ◽  
S. Tsuchiya ◽  
Y. Toda ◽  
T. Kurosawa ◽  
M. Oda ◽  
...  
Keyword(s):  
High Temperature ◽  
Symmetry Breaking ◽  
Probe Beam ◽  
Pump Beam ◽  
High Temperature Superconductor ◽  
Beam Polarization ◽  
Optical Pump ◽  
Quasi Particle ◽  
Time Resolved ◽  
Pump Probe

The dynamics of quasi-particle (QP) excitations with different symmetry is investigated in the superconducting (SC) and pseudogap (PG) states of the high-temperature superconductor [Formula: see text] (Bi2212) using a polarization-sensitive optical pump-probe measurement. The observation of distinct anisotropies for SC excitations and for PG excitations by the probe beam polarization and absence of any dependence on the pump beam polarization evidence the existence of a spontaneous spatial symmetry breaking in the PG state.

scholarly journals Understanding the Seeding Pulse-Induced Optical Amplification in N 2 + Pumped by 800 NM Femtosecond Laser Pulses

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 99
Author(s):  
Zhengquan Fan ◽  
Xiang Zhang ◽  
Qi Lu ◽  
Yu Luo ◽  
Qingqing Liang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Optical Gain ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Time Resolved ◽  
Optical Amplification ◽  
Pump Probe ◽  
Amplification Process ◽  
Energy Amplification

Nitrogen ions pumped by intense femtosecond laser pulses present an optical gain at 391.4 nm, evident by energy amplification of an injected resonant seeding pulse. We report a time-resolved measurement of the amplification process with seeding pulses having varying intensities. It is found that the amplification factor depends on the intensity of the seeding pulse and the effective temporal window for the optical gain becomes longer by applying more intense seeding pulses. These two features are in sharp contrast with classic pump-probe experiments, pinpointing the crucial role of macroscopic coherence and its dynamics during the lasing process. We further measure the temporal profile of the amplified emission for seeding pulse injected at different time delays. A complicated temporal behavior is observed, which highlights the nature of the superfluorescence.

scholarly journals Time-resolved x-ray/optical pump-probe simulations on N2 molecules

2019 ◽  
Vol 6 (2) ◽  
pp. 024101
Author(s):  
Athiya Mahmud Hanna ◽  
Oriol Vendrell ◽  
Robin Santra
Keyword(s):  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray

Time-resolved measurements of optical gain and photoluminescence in silicon nanocrystals

2010 ◽  
Vol T141 ◽  
pp. 014011 ◽  
Author(s):  
K Dohnalová ◽  
K Kůsová ◽  
O Cibulka ◽  
L Ondič ◽  
I Pelant
Keyword(s):  
Silicon Nanocrystals ◽  
Optical Gain ◽  
Time Resolved ◽  
Time Resolved Measurements

scholarly journals Unambiguous determination of spin dephasing times in ZnO by time-resolved magneto-optical pump-probe experiments

2014 ◽  
Vol 251 (9) ◽  
pp. 1861-1871 ◽  
Author(s):  
Sebastian Kuhlen ◽  
Ralph Ledesch ◽  
Robin de Winter ◽  
Matthias Althammer ◽  
Sebastian T. B. Gönnenwein ◽  
...  
Keyword(s):  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
Spin Dephasing ◽  
Unambiguous Determination

scholarly journals Coherent ac spin current transmission across an antiferromagnetic CoO insulator

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Q. Li ◽  
M. Yang ◽  
C. Klewe ◽  
P. Shafer ◽  
A. T. N’Diaye ◽  
...  
Keyword(s):  
Spin Current ◽  
Spin Precession ◽  
Fundamental Physics ◽  
Time Resolved ◽  
Pump Probe ◽  
Insulating Layer ◽  
X Ray ◽  
Current Transmission ◽  
Measurement Results ◽  
Probe Measurements

AbstractThe recent discovery of spin current transmission through antiferromagnetic insulating materials opens up vast opportunities for fundamental physics and spintronics applications. The question currently surrounding this topic is: whether and how could THz antiferromagnetic magnons mediate a GHz spin current? This mismatch of frequencies becomes particularly critical for the case of coherent ac spin current, raising the fundamental question of whether a GHz ac spin current can ever keep its coherence inside an antiferromagnetic insulator and so drive the spin precession of another ferromagnet layer coherently? Utilizing element- and time-resolved x-ray pump-probe measurements on Py/Ag/CoO/Ag/Fe75Co25/MgO(001) heterostructures, here we demonstrate that a coherent GHz ac spin current pumped by the Py ferromagnetic resonance can transmit coherently across an antiferromagnetic CoO insulating layer to drive a coherent spin precession of the Fe75Co25 layer. Further measurement results favor thermal magnons rather than evanescent spin waves as the mediator of the coherent ac spin current in CoO.

scholarly journals Pump-Probe Time-Resolved Serial Femtosecond Crystallography at SACLA: Current Status and Data Collection Strategies

2019 ◽  
Vol 9 (24) ◽  
pp. 5505 ◽  
Author(s):  
Eriko Nango ◽  
Minoru Kubo ◽  
Kensuke Tono ◽  
So Iwata
Keyword(s):  
Data Collection ◽  
Free Electron ◽  
Free Electron Laser ◽  
Current Status ◽  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray ◽  
Collection Strategies ◽  
Serial Femtosecond Crystallography

Structural information on protein dynamics is a critical factor in fully understanding the protein functions. Pump-probe time-resolved serial femtosecond crystallography (TR-SFX) is a recently established technique for visualizing the structural changes or reactions in proteins that are at work with high spatial and temporal resolution. In the pump-probe method, protein microcrystals are continuously delivered from an injector and exposed to an X-ray free-electron laser (XFEL) pulse after a trigger to initiate a reaction, such as light, chemicals, temperature, and electric field, which affords the structural snapshots of intermediates that occur in the protein. We are in the process of developing the device and techniques for pump-probe TR-SFX while using XFEL produced at SPring-8 Angstrom Compact Free-Electron Laser (SACLA). In this paper, we described our current development details and data collection strategies for the optical pump X-ray probe TR-SFX experiment at SACLA and then reported the techniques of in crystallo TR spectroscopy, which is useful in clarifying the nature of reaction that takes place in crystals in advance.

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