Two-Wave Mixing Gain vs Intensity Dependence in Photorefractive GaAs:EL2 in Presence of Strong Electron/Hole Competition

1992 ◽  
Vol 261 ◽  
Author(s):  
Philippe Gravey ◽  
Nicole Wolffer ◽  
Gilbert Picoli ◽  
Olivier Renais ◽  
Jean-Emmanuel Viallet
Keyword(s):  
Grating Period ◽  
Pump Intensity ◽  
Wave Mixing ◽  
Electron Hole ◽  
Strong Electron ◽  
Intensity Dependence ◽  
Sign Changes ◽  
Different Types ◽  
Two Wave Mixing ◽  
Original Feature

ABSTRACTWe studied the pump intensity dependence of the 2WM gain in a photorefractive GaAs:EL2 crystal, with a 3.3 kV/cm d.c. field, at two different wavelengths. The grating period was 37 Am and the beam ratio was 4. At 1.32 μm, the characteristics exhibits a resonant behaviour (with a maximum of 0.23 cm-1). As for InP:Fe, these results can be explained by considering that thermally and optically generated carriers are of different types. The curve at 1.047 Am exhibits an original feature. At low intensities the gain as the same sign than at 1.32 μm (with a maximum of 0.12 cm-1), but the sign changes with increasing intensity and the gain tends towards an asymptotic value of -0.15 cm-1. Such behaviour may also be explained with the same model.

Moving grating and intrinsic electron–hole resonance in two-wave mixing in photorefractive InP:Fe

1990 ◽  
Vol 15 (17) ◽  
pp. 938 ◽  
Author(s):  
B. Mainguet ◽  
G. Picoli ◽  
F. Le Guiner
Keyword(s):  
Wave Mixing ◽  
Electron Hole ◽  
Two Wave Mixing

Model for resonant intensity dependence of photorefractive two-wave mixing in InP:Fe

1989 ◽  
Vol 14 (24) ◽  
pp. 1362 ◽  
Author(s):  
G. Picoli ◽  
P. Gravey ◽  
C. Ozkul
Keyword(s):  
Wave Mixing ◽  
Intensity Dependence ◽  
Two Wave Mixing

Intensity dependence of two-wave mixing absorption in a resonant medium

1987 ◽  
Vol 12 (8) ◽  
pp. 582
Author(s):  
G. S. He ◽  
J. W. Mirick ◽  
R. S. F. Chang ◽  
N. Djeu
Keyword(s):  
Resonant Medium ◽  
Wave Mixing ◽  
Intensity Dependence ◽  
Two Wave Mixing

scholarly journals A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1198
Author(s):  
Stuart McMichael ◽  
Pilar Fernández-Ibáñez ◽  
John Anthony Byrne
Keyword(s):  
Chemical Compounds ◽  
Research Area ◽  
Heterogeneous Photocatalysis ◽  
Semiconducting Materials ◽  
Electron Hole ◽  
Water And Wastewater Treatment ◽  
Aqueous Environments ◽  
Different Types ◽  
Water And Wastewater ◽  
Electrical Bias

The photoexcitation of suitable semiconducting materials in aqueous environments can lead to the production of reactive oxygen species (ROS). ROS can inactivate microorganisms and degrade a range of chemical compounds. In the case of heterogeneous photocatalysis, semiconducting materials may suffer from fast recombination of electron–hole pairs and require post-treatment to separate the photocatalyst when a suspension system is used. To reduce recombination and improve the rate of degradation, an externally applied electrical bias can be used where the semiconducting material is immobilised onto an electrically conducive support and connected to a counter electrode. These electrochemically assisted photocatalytic systems have been termed “photoelectrocatalytic” (PEC). This review will explain the fundamental mechanism of PECs, photoelectrodes, the different types of PEC reactors reported in the literature, the (photo)electrodes used, the contaminants degraded, the key findings and prospects in the research area.

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