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Photochromic effect in LiNbO(3): Fe :Co
Optics Express
|June 25, 2009
Summary
Cobalt codoping in Lithium Niobate: Iron (LiNbO(3): Fe) crystals enhances the photochromic effect. This study elucidates the sensitization and bleaching mechanisms, crucial for advanced optical data storage applications.
Area of Science:
- Solid State Physics
- Materials Science
- Optical Engineering
Background:
- Lithium Niobate (LiNbO(3)) crystals doped with Iron (Fe) are known for their photorefractive properties.
- Photochromism, the reversible change of color upon light exposure, is a key phenomenon for optical data storage.
Purpose of the Study:
- To investigate the effect of Cobalt (Co) codoping on the photochromic properties of LiNbO(3): Fe crystals.
- To elucidate the underlying photochromic mechanism in Co-codoped LiNbO(3): Fe.
Main Methods:
- Synthesis of LiNbO(3): Fe: Co crystals.
- UV-VIS-NIR absorption spectroscopy.
- Photorefractive sensitivity measurements.
- Electron Paramagnetic Resonance (EPR) spectroscopy.
Main Results:
- Co codoping significantly enhances the photochromic effect in LiNbO(3): Fe.
- Sensitization involves electron transfer from O(2-) to Fe(3+) and hole trapping by Co(2+), causing darkening.
- Bleaching occurs via excitation of Fe(2+) electrons and recombination with holes on Co(2+).
- LiNbO(3): Fe: Co exhibits fast sensitization beneficial for two-color recording.
Conclusions:
- Cobalt codoping provides a pathway to tune and enhance the photochromic behavior of LiNbO(3): Fe.
- The proposed mechanism explains the observed sensitization and bleaching processes.
- Fast sensitization in Co-codoped crystals opens possibilities for efficient optical data storage technologies.
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