From analytical and numerical solutions that predict the scattering of diffuse photon density waves and from experimental measurements of changes in phase shift θ and ac amplitude demodulation <i>M</i> caused by the presence of single and double cylindrical heterogeneities, we show that second- and higher-order perturbations can affect the prediction of the propagation characteristics of diffuse photon density waves. Our experimental results for perfect absorbers in a lossless medium suggest that the performance of fast inverse-imaging algorithms that use first-order Born or Rytov approximations might have inherent limitations compared with inverse solutions that use iterative solutions of a linear perturbation equation or numerical solutions of the diffusion equation.
© 1997 Optical Society of America
E. M. Sevick-Muraca, D. L. Heintzelman, J. Lee, T. L. Troy, and D. Y. Paithankar, "Role of higher-order scattering in solutions to the forward and inverse optical-imaging problems in random media," Appl. Opt. 36, 9058-9067 (1997)