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Thermal-Induced
Non-Linearity of Ag Nano-fluid Prepared Using γ-Radiation Method
(Induksi-Terma
Ketidak-Linearan Nanocecair Ag disedia Menggunakan Kaedah Sinaran-γ)
Esmaeil Shahriari, W. Mahmood Mat Yunus*, Zainal Abidin Talib
& Elias Saion
Department of
Physics, Universiti Putra Malaysia
43400 UPM,
Serdang, Selangor D.E., Malaysia
Diserahkan: 7
Disember 2009 / Diterima: 13 Julai 2010
ABSTRACT
The non-linear refractive
index of Ag nano-fluids prepared by γ-radiation method was investigated
using a single beam z-scan technique. Under CW 532 nm laser excitation with
power output of 40 mW, the Ag nano-fluids showed a large thermal-induced
non-linear refractive index. In the present work it was determined that the
non-linear refractive index for Ag nano-fluids is -4.80×10-8 cm2/W.
The value of Δn0 was calculated to be -2.05×10-4.
Our measurements also confirmed that the non-linear phenomenon was caused by
the self-defocusing process making them good candidates for non linear optical
devices.
Keywords:
γ-radiation; nanofluid; non-linear refractive index; z-scan
ABSTRAK
Indek biasan taklinear
nanocecair Ag yang disediakan dengan kaedah sinaran-γ telah dikaji
menggunakan teknik imbasan-z alur laser tunggal. Di bawah pengujaan laser CW
532 nm dengan kuasa sinaran 40 mW, nanocecair Ag telah menunjukkan satu sifat
indeks biasan tak-linear yang besar. Dalam kajian ini ditentukan bahawa indek
biasan tak-linear untuk Ag adalah -4.80×10-8 cm2/W.
Nilai Δn0 telah dikira dan bernilai 2.05×10-4.
Pengukuran kami juga mengesahkan bahawa fenomena tak-linear adalah disebabkan
oleh proses nyahfokus-dirian membuatkan ianya calon yang baik untuk reka bentuk
optik tak-linear.
Kata kunci:
Imbasan-z; indek biasan tak-linear; nanocecair; sinaran-γ
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*Pengarang
untuk surat-menyurat; email: mahmood@science.upm.edu.my
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