“…In the context of optical tomography, in which one seeks to reconstruct coefficients instead of sources, see for example [2,3,4,8,16,15]. Other related optical problems include fluorescent ultrasound modulated optical tomography ( [21,22]) and multifrequency acousto-optic tomography ( [13,14]). Ultrasound modulated hybrid problems are also part of a broader group of hybrid inverse problems in which the interactions of multiple imaging modalities create well-posed problems; for a survey of such ideas, see [6].…”