Off-axis spatiotemporally gated multimode detection toward deep fog imaging.

Towards better imaging through fog for vehicles, we developed an off-axis spatiotemporally gated multimode laser scanning imaging system. Utilizing fog mimicking liquid suspension, we tested the imaging system with different levels of scattering. The experimental results suggest that the system can yield high quality images at seven scattering path lengths, which far exceeds the capability of conventional imaging systems. We also found that the multimode detection can not only make the system robust in the presence of aberration but also help to reduce the speckles in images for the case of coherent illumination.