scholarly journals Multiple phase‐coherent laser pulses in optical spectroscopy. II. Applications to multilevel systems

1983 ◽  
Vol 78 (5) ◽  
pp. 2298-2311 ◽  
Author(s):  
W. S. Warren ◽  
Ahmed H. Zewail
Keyword(s):  
Optical Spectroscopy ◽  
Laser Pulses ◽  
Multilevel Systems ◽  
Multiple Phase

scholarly journals Phase Coherence in Multiple Pulse Optical Spectroscopy

1983 ◽  
Vol 2 (2) ◽  
pp. 37-51 ◽  
Author(s):  
Warren S. Warren ◽  
Ahmed H. Zewail
Keyword(s):  
Optical Spectroscopy ◽  
Chem Phys ◽  
Detection Methods ◽  
Optical Transitions ◽  
Multiple Pulse ◽  
Pulse Trains ◽  
Multilevel Systems ◽  
Relaxation Parameters ◽  
Vibrational Levels ◽  
A New Technique

In this paper we describe a new technique for the generation of multiple pulse phase coherent sequences in optical spectroscopy. The technique is an extension of the acousto-optic modulation and fluorescence detection methods developed for optical transitions by Zewail and Orlowski (Zewail et al., Chem. Phys. Lett.48, 256 (1977); Orlowski et al., Chem. Phys. Lett.54, 197 (1978)). Application of these multiple pulse trains (of different phases) to optical transitions of two-level and multilevel systems is demonstrated experimentally. It is shown that they can be used to (i) suppress spontaneous emission background, (ii) enhance coherent transients such as photon echoes, (iii) measure additional relaxation parameters in systems with complex rotational-vibrational levels, and (iv) enhance the effective laser bandwidths through composite pulse trains, as demonstrated on I2 gas. Finally, the potential of this development is extended to the possibility of observing selective multiquantum excitation in molecules.

Optical spectroscopy study of nano- and microstructures fabricated by femtosecond laser pulses on ZnO based systems

CrystEngComm ◽  
2018 ◽  
Vol 20 (21) ◽  
pp. 2952-2960 ◽  
Author(s):  
Esther de Prado ◽  
Camilo Florian ◽  
Belén Sotillo ◽  
Jan Siegel ◽  
Javier Solis ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Optical Spectroscopy ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Luminescence Properties ◽  
Spectroscopy Study ◽  
Self Organized ◽  
Aspect Ratios

Self-organized nanowires with large aspect ratios and beehive-like structures with well preserved luminescence properties.

Multiple phase transitions investigated by high-speed TEM

1990 ◽  
Vol 48 (4) ◽  
pp. 550-551
Author(s):  
Oleg Bostanjoglo ◽  
Peter Thomsen-Schmidt
Keyword(s):  
Phase Transitions ◽  
High Speed ◽  
Short Exposure ◽  
Semiconductor Film ◽  
Time Resolved ◽  
Short Exposure Time ◽  
Multiple Phase ◽  
Model Substance ◽  
History Of ◽  
Electron Image

Thin GexTe1-x (x = 0.15-0.8) were studied as a model substance of a composite semiconductor film, in addition being of interest for optical storage material. Two complementary modes of time-resolved TEM were used to trace the phase transitions, induced by an attached Q-switched (50 ns FWHM) and frequency doubled (532 nm) Nd:YAG laser. The laser radiation was focused onto the specimen within the TEM to a 20 μm spot (FWHM). Discrete intermediate states were visualized by short-exposure time doubleframe imaging /1,2/. The full history of a transformation was gained by tracking the electron image intensity with photomultiplier and storage oscilloscopes (space/time resolution 100 nm/3 ns) /3/. In order to avoid radiation damage by the probing electron beam to detector and specimen, the beam is pulsed in this continuous mode of time-resolved TEM,too.Short events ( <2 μs) are followed by illuminating with an extended single electron pulse (fig. 1c)

Causal heat transport induced by zeptosecond laser pulses

2002 ◽  
Vol 12 (3) ◽  
pp. 201-206 ◽  
Author(s):  
Janina Marciak-Kozłowska ◽  
Mirosław Kozłowski
Keyword(s):  
Heat Transport ◽  
Laser Pulses

Transient collisional excitation X-ray laser generation with picoseconds laser pulses

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-39-Pr2-42 ◽  
Author(s):  
M. Kado ◽  
T. Kawachi ◽  
N. Hasegawa ◽  
M. Tanaka ◽  
K. Sukegawa ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Laser Generation ◽  
Collisional Excitation ◽  
X Ray
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