Rose Leena Thomas; Dr. Sheenu Thomas(Cochin University of Science and Technology, April 23, 2013)
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Abstract:
Tellurite glasses are photonic materials of special interest to the
branch of optoelectronic and communication, due to its important optical
properties such as high refractive index, broad IR transmittance, low phonon
energy etc. Tellurite glasses are solutions to the search of potential
candidates for nonlinear optical devices. Low phonon energy makes it an
efficient host for dopant ions like rare earths, allowing a better environment
for radiative transitions. The dopant ions maintain majority of their
individual properties in the glass matrix. Tellurites are less toxic than
chalcogenides, more chemically and thermally stable which makes them a
highly suitable fiber material for nonlinear applications in the midinfrared
and they are of increased research interest in applications like laser,
amplifier, sensor etc. Low melting point and glass transition temperature
helps tellurite glass preparation easier than other glass families.In order to probe into the versatility of tellurite glasses in optoelectronic
industry; we have synthesized and undertaken various optical studies on tellurite
glasses. We have proved that the highly nonlinear tellurite glasses are suitable
candidates in optical limiting, with comparatively lower optical limiting
threshold. Tuning the optical properties of glasses is an important factor in
the optoelectronic research. We have found that thermal poling is an
efficient mechanism in tuning the optical properties of these materials.
Another important nonlinear phenomenon found in zinc tellurite glasses is
their ability to switch from reverse saturable absorption to saturable
absorption in the presence of lanthanide ions. The proposed thesis to be
submitted will have seven chapters.