Visually opaque media are ubiquitous in nature. While some materials are opaque because they strongly absorb visible light, others, such as loam, white paint, biological tissue and milk, are opaque because photons traveling within them are predominantly scattered rather than absorbed. A vanishingly small number of photons travel straight through such substances. Instead, light is transported through these materials in a process similar to heat diffusion (figure 1).
Spectroscopy and Imaging with Diffusing Light
Arjun Yodh, Britton Chance; Spectroscopy and Imaging with Diffusing Light. Physics Today 1 March 1995; 48 (3): 34–40. https://doi.org/10.1063/1.881445
Download citation file:
Purchase an annual subscription for $25. A subscription grants you access to all of Physics Today's current and backfile content.