Derivation of a Monte Carlo method for modeling heterodyne detection in optical coherence tomography systems.

A Monte Carlo (MC) method for modeling optical coherence tomography (OCT) measurements of a diffusely reflecting discontinuity embedded in a scattering medium is presented. For the first time to the authors' knowledge it is shown analytically that the applicability of an MC approach to this optical geometry is firmly justified, because, as we show, in the conjugate image plane the field reflected from the sample is delta-correlated from which it follows that the heterodyne signal is calculated from the intensity distribution only. This is not a trivial result because, in general, the light from the sample will have a finite spatial coherence that cannot be accounted for by MC simulation. To estimate this intensity distribution adequately we have developed a novel method for modeling a focused Gaussian beam in MC simulation. This approach is valid for a softly as well as for a strongly focused beam, and it is shown that in free space the full three-dimensional intensity distribution of a Gaussian beam is obtained. The OCT signal and the intensity distribution in a scattering medium have been obtained for several geometries with the suggested MC method; when this model and a recently published analytical model based on the extended Huygens-Fresnel principle are compared, excellent agreement is found.

[2]  R Birngruber,et al.  Low-coherence optical tomography in turbid tissue: theoretical analysis. , 1995, Applied optics.

[3]  L Wang,et al.  MCML--Monte Carlo modeling of light transport in multi-layered tissues. , 1995, Computer methods and programs in biomedicine.

[4]  T Lindmo,et al.  Signal attenuation and localization in optical coherence tomography studied by Monte Carlo simulation. , 1998, Physics in medicine and biology.

[5]  A. Siegman,et al.  The antenna properties of optical heterodyne receivers. , 1966, Applied optics.

[6]  A. Welch,et al.  A review of the optical properties of biological tissues , 1990 .

[7]  Comment on "Excitation with a focused, pulsed optical beam in scattering media: diffraction effects". , 2002, Applied optics.

[8]  A J Welch,et al.  Sources of contrast in confocal reflectance imaging. , 1996, Applied optics.

[9]  J M Schmitt,et al.  Efficient Monte Carlo simulation of confocal microscopy in biological tissue. , 1996, Journal of the Optical Society of America. A, Optics, image science, and vision.

[10]  C Saloma,et al.  Monte carlo analysis of two-photon fluorescence imaging through a scattering medium. , 1998, Applied optics.

[11]  X. H. Hu,et al.  Monte carlo simulation of converging laser beams propagating in biological materials. , 1999, Applied optics.

[12]  J. Fujimoto,et al.  Optical Coherence Tomography , 1991 .

[13]  L. Wang,et al.  Absorption distribution of an optical beam focused into a turbid medium. , 1999, Applied optics.

[14]  W. Denk,et al.  Two-photon laser scanning fluorescence microscopy. , 1990, Science.

[15]  N. Bloembergen,et al.  Laser-induced electric breakdown in solids , 1974 .

[16]  J. Schmitt,et al.  Confocal microscopy in turbid media. , 1994, Journal of the Optical Society of America. A, Optics, image science, and vision.

[17]  H. Yura,et al.  Closed-form solution for the Wigner phase-space distribution function for diffuse reflection and small-angle scattering in a random medium. , 2000, Journal of the Optical Society of America. A, Optics, image science, and vision.

[18]  H. Yura,et al.  Analysis of optical coherence tomography systems based on the extended Huygens-Fresnel principle. , 2000, Journal of the Optical Society of America. A, Optics, image science, and vision.

[19]  Joseph M. Schmitt,et al.  MODEL OF OPTICAL COHERENCE TOMOGRAPHY OF HETEROGENEOUS TISSUE , 1997 .

[20]  H. Yura,et al.  Optical beam wave propagation through complex optical systems , 1987 .

[21]  I. Dror,et al.  Experimental investigation of the influence of the relative position of the scattering layer on image quality: the shower curtain effect. , 1998, Applied optics.

[22]  L V Wang,et al.  Monte Carlo simulation of an optical coherence tomography signal in homogeneous turbid media. , 1999, Physics in medicine and biology.

[23]  H.J.C.M. Sterenborg,et al.  Skin optics , 1989, IEEE Transactions on Biomedical Engineering.

[24]  H. T. Yura,et al.  Signal-to-noise Ratio of Heterodyne Lidar Systems in the Presence of Atmospheric Turbulence , 1979 .

[25]  S Andersson-Engels,et al.  Mathematical modelling of dynamic cooling and pre-heating, used to increase the depth of selective damage to blood vessels in laser treatment of port wine stains , 1996, Physics in medicine and biology.

[26]  B. Wilson,et al.  A Monte Carlo model for the absorption and flux distributions of light in tissue. , 1983, Medical physics.