Dynamic Speckle: Origin and Features (Chap. 2)

MARCELO TRIVI

Dynamic Laser Speckle and Applications

TAYLOR & FRANCIS INC

Lugar: Boca Raton, Fl, USA; Año: 2009; p. 21 - 52

  In this chapter, we introduce some concepts to discuss the origin and features of the biospeckle phenomenon. We start with a brief description of the various ways in which the light interacts with matter. In particular, with the applications of lasers to biology and medicine based on the use of numerous phenomena associated with various effects of interaction of light with biological objects. Light can be reflected, scattered, absorbed or reradiating when it interacts with bio-objects. These phenomena are analyzed using Fresnel coefficients, Lambert-Beer law and scattering theory. As biospeckle phenomenon is characteristic of biological samples, we present a description of the cells that are the main components of living tissues and we analyze their optical properties. A brief description of the statistical properties of the biospeckle patterns, such the size, the intensity and the depth is included. Chapter 4 is devoted to presenting a deep analysis of these properties. We also included some examples of biospeckle phenomenon and its origin in non-biological samples. We present the cases of the paint drying, corrosion, foams and salt efflorescence. These cases will be analyzed in more detail in the Chapter 9.