A gradient-based optimisation scheme foroptical tomography.

Optical tomography schemes using non-linear optimisation are usually based on a Newton-like method involving the construction and inversion of a large Jacobian matrix. Although such matrices canbe efficiently constructed using a reciprocity principle, their inversion is still computationally diffcult. In this paper we demonstrate a simple means to obtain the gradient of the objective function directly, leading to straightforward application of gradient-based optimisation methods.