Sains Malaysiana 40(1)(2011): 13–15

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

Received: 7 December 2009 / Accepted: 13 July 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

REFERENCES

Almond, D.P. & Patel, P.M. 1996. Photothermal Science and Techniques. London: Chapman & Hall.

Chen, P., Oulianov, D.A., Tomov, I.V. & Rentzepis, P.M. 1999. Two-dimensional Z scans for arbitrary beam shape and sample thickness. J. Appl. Phys. 85: 7043-7051.

Jia, T., He, T., Li, P., Mo, Y. & Cui, Y. 2008. A study of the thermal-induced non-linearity of Au and Ag colloids prepared by the chemical reaction method. Optics & Laser Technology 40: 936-940.

Li, H.P., Kam, C.H., Lam, Y.L. & Ji, W. 2001. Femtosecond Z-scan measurements of non-linear refraction in non-linear optical crystals. Optical Materials 15: 237-242.

Liao, H.B., Xiao, R F., Fu, J.S., Wang, H., Wong, K.S. & Wong. G.K.L. 1998. Origin of third-order optical non-linearity in Au:SiO2 composite films on femtosecond and picosecond time scales. Optics Letters 23: 388-390.

Liao, H.B., Xiao, R.F., Fu, J.S., Yu. P., Wong, G.K.L. & Sheng, P. 1997. Large third-order optical non-linearity in Au:SiO2 composite films near the percolation threshold. Appl. Phys. Lett. 70: 1-2.

Moran, M.J., She, C.Y. & Carman, R.L. 1975. Interferometric measurements of the non-linear refractive-index coefficient relative to CS2 in laser-system-related materials IEEE J. Quantum Electron. 11: 259-263.

Oliveira, L.C & Zilio, S.C. 1994. Single-beam time-resolved Z-scan measurements of slow absorbers. Applied Physics Letters 65: 2121-2124.

Palpant, B. 2006. Non-linear Optical Properties of Matter, edited by Papadopoulos M.G. New York: Springer.

Sheik-Bahae, Said, M., Wei, A.A., Hagan, T.H. & D.J. Van Stryland, E.W. 1990. Sensitive Measurement of optical non-linearities using a single beam. IEEE J. Quantun Electron. 26: 760-769.

Sutherland, R.L. 1996. Handbook of Non-linear Optics, New York: Marcel Dekker.

Xia, T., Hagan, D.J., Sheik Bahae, M. & Van Stryland, E.W. 1994. Eclipsing Z-scan measurement of λ/104 wave-front distortion. Opt. Lett, 19: 317-319.

Yang, G., Guan, D.Y., Wang, W.T., Wu, W.D. & Chen, Z.H. 2004. The inherent optical non-linearities of thin silver films Optical Materials 25: 439-443.

Yüksek, M., Ceyhan, T., Bağcı, F., Gül Yağlıoğlu, H., Elmali, A. & Bekaroğlu, Ö. 2008. The non-linear refraction and absorption dependence on the thermal effect for 4ns pulse duration in binuclear Zn(II) phthalocyanine solution. Opt. Commun. 281: 3897-3901.

*Corresponding author; email: mahmood@science.upm.edu.my