Aneeshkumar, B; Pramod, Gopinath; Jayan,Thomas; Vallabhan, C P G; Nampoori, V P N; Radhakrishnan, P(Elsevier, June , 2004)
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Abstract:
The nanosecond optical limiting characteristics of sandwich-type neodymium diphthalocyanine in a co-polymer matrix of polymethyl methacrylate (PMMA) and methyl-2-cyanoacrylate have been studied for the first time. The measurements were performed using 9 ns laser pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The optical limiting performance of neodymium diphthalocyanine in co-polymer host was studied at different linear transmission. Laser damage threshold was also measured for the doped and undoped co-polymer samples. The optical limiting response is attributed to reverse saturable absorption which is due to excited-state absorption.
Aparna, Thankappan; Dr. V P N Nampoori(Cochin University of Science and Technology, February 10, 2015)
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Abstract:
Green energy and Green technology are the most of the quoted terms in the
context of modern science and technology. Technology which is close to nature
is the necessity of the modern world which is haunted by global warming and
climatic alterations. Proper utilization of solar energy is one of the goals of
Green Energy Movement.
The present thesis deals with the work carried out in the eld of nanotechnology
and its possible use in various applications (employing natural dyes)
like solar cells. Unlike arti cial dyes, the natural dyes are available, easy to
prepare, low in cost, non-toxic, environmentally friendly and fully biodegradable.
Looking to the 21st century, the nano/micro sciences will be a chief contributor
to scienti c and technological developments. As nanotechnology progresses
and complex nanosystems are fabricated, a growing impetus is being
given to the development of multi-functional and size-dependent materials. The
control of the morphology, from the nano to the micrometer scales, associated
with the incorporation of several functionalities can yield entirely new smart hybrid
materials. They are special class of materials which provide a new method
for the improvement of the environmental stability of the material with interesting
optical properties and opening a land of opportunities for applications
in the eld of photonics. Zinc oxide (ZnO) is one such multipurpose material
that has been explored for applications in sensing, environmental monitoring,
and bio-medical systems and communications technology. Understanding the
growth mechanism and tailoring their morphology is essential for the use of
ZnO crystals as nano/micro electromechanical systems and also as building
blocks of other nanosystems.