Coherent components of forward light propagation through scattering mediaComposantes cohrentes de l

The transmitted light through random media is studied at nm with a Mach - Zehnder interferometer. The optical heterodyne detection used allows a coherent detection with a sensitivity corresponding to an optical thickness of 25. In addition to the standard exponential decrease for the transmitted light in accordance with the scattering cross section value computed from the Mie theory, we observed a distinct component for optical thicknesses above 15 and 17 for polystyrene beads with diameters of 0.94 and respectively. This second component, involving light scattered onto the detector, was hardly detected with smaller scatterers but is clearly present in tissue samples. A measurement of the angular distribution of the scattered light confirmed the coherent detection of non-ballistic light for particle suspensions and blood samples. La lumi?re transmise au travers de milieux al?atoires a ?t? ?tudi?e ? avec un interf?rom?tre de Mach - Zehnder. La d?tection h?t?rodyne optique utilis?e permet une d?tection coh?rente avec une sensibilit? correspondant ? une ?paisseur optique de 25. En plus de la d?croissance exponentielle standard de la lumi?re transmise conforme ? la valeur de la section efficace de diffusion calcul?e d'apr?s la th?orie de Mie, on observe une composante distincte pour des ?paisseurs optiques sup?rieures ? 15 et 17 avec des billes de polystyrene d'un diam?tre de 0,94 et de respectivement. Cette deuxi?me composante, qui implique un battement de la lumi?re diffus?e avec l'onde de r?f?rence, est difficilement d?tectable avec les petits diffuseurs mais clairement observ?e avec les tissus. Une mesure de la distribution angulaire de la lumi?re diffus?e confirme la d?tection coh?rente d'une composante non-balistique autant pour les suspensions de particules que pour les ?chantillons de sang.

[1]  E. Leith,et al.  Ensemble-averaged imaging through highly scattering media. , 1996, Optics letters.

[2]  H. Inaba,et al.  Coherence gating in optical heterodyne detection measurements of scattering and absorption in highly scattering media , 1996 .

[3]  H. J. Schnorrenberg,et al.  The attenuation of a coherent field by scattering , 1995 .

[4]  G. Jarry,et al.  Extinction measurements in diffusing mammalian tissue with heterodyne detection and a titanium:sapphire laser. , 1995, Applied optics.

[5]  G. Jarry,et al.  Heterodyne detection for measuring extinction coefficient in mammalian tissue , 1993 .

[6]  J. Schmitt,et al.  Measurement of optical properties of biological tissues by low-coherence reflectometry. , 1993, Applied optics.

[7]  R R Alfano,et al.  Ultrafast time-gated imaging in thick tissues: a step toward optical mammography. , 1993, Optics letters.

[8]  E A Swanson,et al.  Femtosecond transillumination tomography in thick tissues. , 1993, Optics letters.

[9]  J. Fujimoto,et al.  Femtosecond transillumination optical coherence tomography. , 1993, Optics letters.

[10]  R R Alfano,et al.  Imaging of a translucent object hidden in a highly scattering medium from the early portion of the diffuse component of a transmitted ultrafast laser pulse. , 1992, Optics letters.

[11]  R. Alfano,et al.  Ballistic 2-D Imaging Through Scattering Walls Using an Ultrafast Optical Kerr Gate , 1991, Science.

[12]  M. Long,et al.  Technique for three-dimensional measurements of the time development of turbulent flames. , 1991, Optics letters.

[13]  R R Alfano,et al.  Speed of the coherent component of femtosecond laser pulses propagating through random scattering media. , 1991, Optics letters.

[14]  R. Alfano,et al.  Time-resolved coherent and incoherent components of forward light scattering in random media. , 1990, Optics letters.

[15]  A. P. Shepherd,et al.  Comparison of Mie theory and the light scattering of red blood cells. , 1988, Applied optics.

[16]  Akira Ishimaru,et al.  Experiments on picosecond pulse propagation in a diffuse medium , 1983 .

[17]  Akira Ishimaru,et al.  Scattering and diffusion of a beam wave in randomly distributed scatterers , 1983 .

[18]  Yasuo Kuga,et al.  Attenuation constant of a coherent field in a dense distribution of particles , 1982 .