Lipschitz stability at the boundary for time-harmonic diffuse optical tomography

We study the inverse problem in Optical Tomography of determining the optical properties of a medium ⊂ Rn, with n ≥ 3, under the so-called diffusion approximation. We consider the time-harmonic case where is probed with an input field that is modulated with a fixed harmonic frequency ω = k/c, where c is the speed of light and k is the wave number.