Optical imaging based on frequency-domain radiative transfer model

This study focuses on the optical imaging of the participating media exposed to ultra-short pulse laser. The forward model of simulating the radiative transfer in the media exposed to frequency-modulated pulse laser and the inverse model of retrieving the internal optical parameters of the media based on the detected boundary frequency information are developed, respectively. Based on the transient radiative transfer equation (RTE), the RTE in frequency domain was deduced by the Fourier Transform. The finite volume method was used to solve the frequency domain RTE. The transmission process of ultrashort pulse laser in the participating media was simulated. The transmitted radiation signals on the edge of the media were obtained. The conjugate gradient method was selected as the inversion algorithm, and the adjoint differentiation method was applied to solve the gradient of the ob jective function. The optical parameters of the two-dimensional inhomogeneous media with non-uniform distributed inclusions were reconstructed. The retrieval results show that the adjoint differentiation models based on RTE in frequency domain can reconstruct the optical parameters of the multi-dimensional participating media accurately.