Absolute values of transport mean free path of light in non–absorbing media using transmission and reflectance measurements
J. Galvan–Miyoshi and R. Castillo*
Instituto de Física, Universidad Nacional Autónoma de México, P.O. Box20–364, México, 01000 D.F.
* Author to whom correspondence should be addressed:
e–mail: rolandoc@fisica.unam.mx
Recibido el 19 de febrero de 2008
Aceptado el 23 de abril de 2008
Abstract
We derived a relation between the transport mean free path of light, and transmittance and the reflectance in non–absorbing turbid media. This allowed us to develop an experimental procedure to obtain absolute values for the transport mean free path of light just by measuring in an integrating sphere both the transmittance and the reflectance in this kind of system. We determined how accurate our method was by comparing our transport mean free path measurements with calculations made for colloidal suspensions of particles using Mie scattering theory and with measurements made in colloidal suspensions of polystyrene microspheres using diffusive wave spectroscopy. The agreement is excellent.
Keywords: Transport mean free path of light; DWS.
Resumen
En este trabajo se deriva una relación entre el camino libre medio de trasporte de la luz y la transmitancia y la reflectancia de un medio turbio no absorbente. Esto nos permitió desarrollar un procedimiento experimental para obtener valores absolutos de los caminos libres medio de transporte de la luz con solo medir, en una esfera integradora, la trasnmitancia y la reflectancia en esta clase de sistemas. Hemos determinado cuán preciso es nuestro método comparando nuestras medidas de camino libre medio de transporte con cálculos efectuados para suspensiones coloidales utilizando la teoría de dispersión de Mie y con medidas hechas en suspensiones coloidales de microesferas utilizando espectroscopia de onda difusa. El acuerdo es excelente.
]]> Descriptores: Camino libre medio de trasporte de luz; DWS.
PACS: 82.70.Dd; 87.64Cc; 78.20.Ci
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References
1. D.A. Weitz, D. J. Pine in: Dynamic Light Scattering, W. Brown (Ed.). (Oxford University Press, New York, 1993) Chap. 16, p. 652. [ Links ]
2. J.L. Harden and V. Viasnoff, Curr. Opin. Colloid. Interface Sci. 6 (2001) 438. [ Links ]
3. D.J. Pine, D.A. Weitz, P.M. Chaikin, and E. Herbolzheimer, Phys. Rev. Lett. 60 (1988) 1134. [ Links ]
4. F. Scheffold, J. Dispersion Sci. and Technol. 23 (2002) 591. [ Links ]
5. L.F. Rojas–Ochoa, D. Lacoste, R. Lenke, P. Schurtenberger, and F. Scheffold, J. Opt. Soc. Am. A. 21 (2004) 1799. [ Links ]
6. S. Mitani, K. Sakai, and K. Takagi, Jpn. J. Appl. Phys. 39 (2000) 146. [ Links ]
7. N. Garcia, A.Z. Genack, and A.A. Lisyansky, Phys. Rev. B. 46 (1992) 14475. [ Links ]
8. J.W. Pickering, C.J.M. Moes, H.J.C.M. Sterenborg, S.A. Prahl, and M.J.C. van Gemert, J. Opt. Soc. Am. A 9 (1992) 621. [ Links ]
9. J.W. Pickering, S.A. Prahl, N. van Wieringen, J.F. Beek, H.J.C.M. Sterenborg, and M.J.C. van Gemert, App. Opt. 32 (1993) 399. [ Links ]
10. P.D. Kaplan, M.H. Kao, A.G. Yodh, and D.J. Pine, Appl. Opt. 32 (1993) 3828. [ Links ]
11. A. Ishimaru, Wave Propagation and Scattering in Random Media (Academic Press, New York, 1978). [ Links ]
12. H.C. van de Hulst. Light Scattering by Small Particles (Dover, New York, 1981). [ Links ]
13. G.K. Batchelor, J. Fluid Mech. 74 (1976) 1. [ Links ]
14. J.X. Zhu, D.J. Pine, D.A. Weitz, Phys. Rev. A 44 (1991) 3948. [ Links ]
15. L.F. Rojas–Ochoa, S. Romer, F. Scheffold, and P. Schurtenberger, Phys. Rev. E. 65 (2002) 051403. [ Links ]
16. M.S. Wertheim, Phys. Rev. Lett. 10 (1963) 321. [ Links ] ]]>