VENKATESH GOPAL, S ANANTHA RAMAKRISHNA*, A K SOOD and N KUMAR*

Department of Physics, Indian Institute of Science, Bangalore 560 012, India

* Raman Research Institute, C.V. Raman Avenue, Bangalore 560 080, India

Email: asood@physics.iisc.ernet.in; nkumar@rri.res.in

Abstract.

We examine using Monte Carlo simulations, photon transport in optically 'thin' slabs whose thickness L is only a few times the transport mean free path l*, with particles of different scattering anisotropies. The confined geometry causes an auto-selection of only photons with looping paths to remain within the slab. The results of the Monte Carlo simulations are borne out by our analytical treatment that incorporates directional persistence by the use of the Ornstein – Uhlenbeck process, which interpolates between the short time ballistic and long time diffusive regimes.

Keywords: Photon migration; persistent random walks; Monte Carlo simulation.

Pacs Nos. 42.25.Bs; 05.60.+w; 42.68.Ay