Enhancement of the signal-to-background ratio in photorefractive two-wave mixing by mutually incoherent two-beam coupling

1994 ◽  
Vol 19 (14) ◽  
pp. 1070 ◽  
Author(s):  
S. Breugnot ◽  
M. Defour ◽  
D. Dolfi ◽  
H. Rajbenbach ◽  
J.-P. Huignard
Keyword(s):  
Wave Mixing ◽  
Background Ratio ◽  
Beam Coupling ◽  
Two Wave Mixing

BEAM COUPLING CHARACTERISTICS IN NEMATIC LIQUID CRYSTAL DOPED WITH SILVER NANOPARTICLES

2008 ◽  
Vol 17 (04) ◽  
pp. 377-385 ◽  
Author(s):  
YONG-YUAN JIANG ◽  
JING LI ◽  
LIN-YI HUANG
Keyword(s):  
Image Processing ◽  
Silver Nanoparticles ◽  
Photorefractive Effect ◽  
The Self ◽  
Wave Mixing ◽  
Signal Ratio ◽  
Beam Coupling ◽  
Two Wave Mixing ◽  
Pump Signal ◽  
Coupling Characteristics

The orientational photorefractive effect was observed in the nematic liquid crystals E7 doped with silver nanoparticles. Both the self-diffraction and beam-coupling effects were studied in a two-wave-mixing experiment with an applied external DC field. The dependence of diffraction efficiency on the applied voltage, pump power, pump/signal ratio and grating constant were studied. Experimental results indicate that the optical non-linearity of NLCs can be enhanced significantly by doping silver nanoparticles. Further experiments demonstrate that the holographic grating formed in the sample can be switched on and off by the external DC field. PR two-beam coupling experiment was also performed in the Ag-doped NLCs cell. These results are of benefit to the applications of PR NLCs in holography and image processing.

Homodyne detection of ultrasonic surface displacements using two-wave mixing in photorefractive polymers

1999 ◽  
Author(s):  
Marvin B. Klein ◽  
Gerald D. Bacher ◽  
Anders Grunnet-Jepsen ◽  
Daniel Wright ◽  
William E. Moerner
Keyword(s):  
Wave Mixing ◽  
Homodyne Detection ◽  
Surface Displacements ◽  
Photorefractive Polymers ◽  
Two Wave Mixing

Impact of donor compensation ratio on photorefractive two–wave mixing dynamics in multiple quantum wells structures

2014 ◽  
Vol 23 (03) ◽  
pp. 1450029 ◽  
Author(s):  
Błażej Jabłoński
Keyword(s):  
Quantum Wells ◽  
Concentration Ratio ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Wave Mixing ◽  
Compensation Ratio ◽  
Mixing Dynamics ◽  
Two Wave Mixing ◽  
Charge Field ◽  
The Impact

The kind of defects and their concentration have a significant impact on photorefractive phenomena taking place within the structure of semi-insulating GaAs / AlGaAs multiple quantum wells. In this paper, the impact of donor-to-acceptor concentration ratio on the grating in photorefractive two-waves mixing was examined. The formation of the space charge field for different defect concentrations as well as different external electric field intensities are analyzed.

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