High-speed photoacoustic-guided wavefront shaping for focusing light in scattering media

Wavefront shaping is becoming increasingly attractive as it promises to enable various biomedical applications by breaking through the optical diffusion limit that prevents light focusing at depths larger than similar to 1 mm in biological tissue. However, despite recent advancements in wavefront shaping technology, such as those exploiting non-invasive photoacoustic-guidance, in vivo demonstrations remain challenging mainly due to rapid tissue speckle decorrelation. In this work, we report a high-speed photoacoustic-guided wavefront shaping method with a relatively simple experimental setup, based on the characterization of a scattering medium with a real-valued intensity transmission matrix. We demonstrated light focusing through an optical diffuser by optimizing 4096 binary amplitude modulation modes of a digital micromirror device within similar to 300 ms, leading to a system runtime of 75 mu s per input mode, which is 3 orders of magnitude smaller than the smallest runtime reported in literature so far using photoacoustic-guided wavefront shaping. Thus, our method is a solid step forward toward in vivo applications of wavefront shaping. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

Automated summary

Wavefront shaping technology holds great promise for enabling light focusing deep into biological tissue, but in vivo demonstrations remain challenging. This study presents a high-speed photoacoustic-guided wavefront shaping method based on the characteristics of a scattering medium, achieving significant results through optimization of binary amplitude modulation modes of a digital micromirror device.