Photoluminescence of Eu3+ in Si/SiO2 Nanostructure Films

2000 ◽  
Vol 609 ◽  
Author(s):  
Huimin Liu ◽  
Aziz Mahfoud ◽  
G. A. Nery ◽  
O. Resto ◽  
Luis F. Fonseca ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Life Time ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Intense Laser ◽  
Time Resolved ◽  
Silicon Matrix ◽  
Sputtering Deposition ◽  
Direct Excitation

ABSTRACTEu3+ -doped Si/SiO2 nanocomposites were successfully prepared by Ar sputtering deposition on quartz substrates. The optical properties were studied using time-resolved photoluminescence spectroscopy. Excited by intense picosecond laser pulses with energy greater than1GW/cm2 and wavelength at 532nm the observed photoluminescence consists of a rapidly decaying component with life time of ∼1 s and a slowly component with life time of ∼ 2 ms. The former was recognized as coming from Si/SiO2 nanostructures matrix while the latter as coming from the impurity Eu3+ ions. Using the intense laser excitation a two-photon absorption by silicon matrix occurred, resulting in photo-induced carriers produced in conduction band. A direct recombination from Si/SiO2 nanostructure host gives a weak but fast emission, and creates a large number of nonequilibrium phonon. For Eu3+ emission a set of 5D0 to 7F multiplet transitions were identified. In addition to the direct excitation by 532nm the excited state 5D0 of Eu3+ ions was also found to be populated due to energy transfer from silicon matrix. The mechanism of phonon-assisted energy transfer is discussed.

scholarly journals Ultrafast F2− photodissociation by intense laser pulses: a time-resolved fragment imaging study

2019 ◽  
Vol 205 ◽  
pp. 09012
Author(s):  
Abhishek Shahi ◽  
Yishai Albeck ◽  
Daniel Strasser
Keyword(s):  
Single Photon ◽  
Imaging Study ◽  
Laser Pulses ◽  
Intense Laser ◽  
Time Resolved ◽  
Intense Field ◽  
Intense Laser Pulses ◽  
Ultrafast Pulses ◽  
Coincidence Imaging ◽  
Field Dissociation

We present time-resolved coincidence imaging of F2− photodissociation by 400nm and intense 800nm ultrafast pulses. Coincidence fragment imaging reveals parallel and perpendicular single photon dissociation on 2Σg+ and 2πg states, and additional intense-field dissociation features.

COMPARATIVE STUDIES ON THE THIRD-ORDER NONLINEAR OPTICAL PROPERTIES OF THREE METAL-ORGANIC COMPOUNDS

2011 ◽  
Vol 20 (02) ◽  
pp. 229-236 ◽  
Author(s):  
PENGFEI ZHANG
Keyword(s):  
Near Infrared ◽  
Heavy Atom ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Optical Limiting ◽  
Infrared Region ◽  
Photon Absorption ◽  
Third Order ◽  
The Third ◽  
Planar Transition

The third-order optical nonlinearities of three planar transition metal ( Ni, Cu and Pd ) compounds with rigid quadridentate Schiff base derived from S-benzyl dithiocarbazate, were investigated systematically by Z-scan technique with picosecond laser pulses at 1064 nm. The three compounds exhibit both strong two-photon absorption and effective self-focusing performance. Due to the heavy atom effect, the second hyperpolarizability of PdZ molecule (〈γ〉 = 1.2 × 10-29 esu) was found to be the highest compared to that of the other two molecules. The optical limiting properties were also measured, and the results suggest that PdZ may be a promising candidate for the application to optical limiting in the near-infrared region.

Self-Guided Intense Laser Pulse Propagation in Air

2001 ◽  
Vol 6 (1) ◽  
pp. 21-26
Author(s):  
R. Danielius ◽  
D. Mikalauskas ◽  
A. Dubietis ◽  
A. Piskarskas
Keyword(s):  
Laser Pulse ◽  
Laser Beam ◽  
Phase Modulation ◽  
Large Scale ◽  
Pulse Propagation ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Intense Laser ◽  
Intense Laser Pulse ◽  
Self Phase Modulation

We report on observation of self-guiding of picosecond laser pulses in air that produces large-scale self-phase modulation. The converging picosecond laser beam produced a confined filament over 3 m of propagation with the whitelight spectrum.

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