Focusing Through Scattering Media Via 1D Speckle Signal Feedback

Abstract

Light propagation in complex media results in strong scattering. While wavefront shaping (WFS) enables the focusing of light at depth, its speed is mainly limited by the frame rate of the area-array detectors. The photodetector has been used to achieve fast focusing, but it cannot record sufficient speckle information, limiting its applications in multi-point focusing and non-invasive focusing. Here, a method for invasively or non-invasively focusing through scattering media is proposed by using 1D speckle signals as feedback for wavefront shaping. Experimentally, not only invasive multi-point focusing can be realized, but also by maximizing the contrast of linear fluorescent 1D speckle signals, non-invasive focusing can be achieved, suggesting the effectiveness of the proposed method. This approach can be generalized to the utilization of linear array detectors in WFS and may hold interesting prospects for rapid focusing light within deep biological tissues.