“The nature of the association between absorbing and scattering structures in living cells is undoubtedly complex; even when all scattered light is collected, the contributions of different substances to the total absorption may depend not only on their quantity but also on their location within the cell.”
Monk, G.W., Journal of Bacteriology, 74, 71 (1957).
“It is possible, however, to study the spectral absorption of the pigment while it is still in the cells. …The added scattering due to the sample is insignificant and its absorption alone determines the transmission of the slab relative to a similar slab without absorber in the reference beam.”
Richetta, P.J., Journal of the Optical Society of America, 55(1), 21 (1965).
“This paper reports a theory of integrating spheres filled completely with absorbing and scattering material. The development is oriented toward describing the behavior of such an integrating sphere when it is used as a spectrophotometer. The output ratio and effective light-path length of an integrating sphere spectrophotometer are introduced.”
“In contrast to Elterman’s work, here we emphasize an integrating cavity that is completely filled with an absorbing sample, which generally will be considered to be an aqueous suspension or solution. Because the diffuse reflecting cavity walls have high reflectivity, the effective absorption length in the sample is many times the diameter of the integrating cavity…Measurement of very small absorptions is facilitated by the use of long path lengths through the sample…this integrating cavity concept is especially sensitive to small absorptions.”
Merzlyak, M.N., Naqvi, K.R., Journal of Photochemistry and Photobiology B, 58, 123(2000).
“An integrating sphere is often used for recording the absorption spectrum of a turbid sample. If the sample is placed inside the sphere, scattering losses are eliminated, but the recorded spectrum suffers from other distortions.”
Rohwer, L.S., Martin, J.E., Journal of Luminescence, 115, 77 (2005).
“We conclude that this diffuse light method gives repeatable values comparable to those currently accepted….We use the approximation that the light in the integrating sphere, after hitting the diffuser, can be described as a gas of photons, so that the photon flux is uniform in all directions.”