Scattering media objects

In a preliminary experiment, we have compared coherent and incoherent imaging of a strongly absorbing object suspended in a highly scattering medium. As a test object, we have used a 2-mm wide, flat metal plate (totally absorbing) suspended in a 10-mm wide cuvet containing a diluted solution of milk. When the cuvet... 

Figure 7. Comparison of images of absorbing objects embedded in a nonscattering medium (left) or a scattering medium (right).

K.M. Yoo, B.B. Das, R.R. Alfano Imaging of a translucent object hidden in highly scattering medium from the early portion of the diffuse component of a transmitted ultrafast laser pulse. Opt. Lett. 17, 958 (1992)... 

Haze characterizes the loss of contrast that results when objects are viewed through a scattering medium. The deterioration of contrast is mainly due to light scattered forward at large angles to the undeviated transmitted beam and is usually expressed through the forward-scattered fraction. 

In the dense interstellar medium characteristic of sites of star fonuation, for example, scattering of visible/UV light by sub-micron-sized dust grains makes molecular clouds optically opaque and lowers their internal temperature to only a few tens of Kelvin. The thenual radiation from such objects therefore peaks in the FIR and only becomes optically thin at even longer wavelengths. Rotational motions of small molecules and rovibrational transitions of larger species and clusters thus provide, in many cases, the only or the most powerfiil probes of the dense, cold gas and dust of the interstellar medium. 

Noise Control Sound is a fluctuation of air pressure that can be detected by the human ear. Sound travels through any fluid (e.g., the air) as a compression/expansion wave. This wave travels radially outward in all directions from the sound source. The pressure wave induces an oscillating motion in the transmitting medium that is superimposed on any other net motion it may have. These waves are reflec ted, refracted, scattered, and absorbed as they encounter solid objects. Sound is transmitted through sohds in a complex array of types of elastic waves. Sound is charac terized by its amplitude, frequency, phase, and direction of propagation. 

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