2-D PSTD Simulation of focusing monochromatic light through a macroscopic scattering medium via optical phase conjugation

Abstract

By employing the pseudospectral time-domain (PSTD)simulation technique, we analyze the propagation of monochromatic light through a macroscopic scattering medium. Simulation results show that, monochromatic light can be directed through a scattering medium and focus into a narrow peak; a range of wavelengths has been simulated. Furthermore, we compare: i) focusing monochromatic light through a macroscopic scattering medium, and, ii) focusing monochromatic light through vacuum. Based upon numerical solutions of Maxwell's equations, we demonstrate: with a fully-surrounding wavefront of specific amplitude and phase, sub-diffraction focusing can be achieved with monochromatic light, with or without the presence of a scattering medium.

Finite-difference time-domain analysis of increased penetration depth in optical coherence tomography by wavefront shaping

“…Various solutions proposed so far, including optical clearing method [6][7][8], may be applicable in some situations, but a universal method that can fundamentally reduce multiple scattering-related decoherence without physically altering the sample has yet to be discovered. To remedy this situation, wavefront shaping, which has been successfully utilized for various other purposes [9][10][11][12][13][14][15][16][17][18], was recently applied for the first time to OCT [19,20]. The experimental results suggested that the penetration depth can indeed be extended.…”