Focusing scattered light through live tissue with channel-selected wavefront shaping

Wavefront shaping (WS) is a powerful technique to overcome optical scattering in biological tissue, enabling deep-tissue focusing and advancing biomedical optics. For practical in vivo applications, WS must adapt to dynamic scattering environments induced by physiological activities such as blood flow. Conventional strategies to address this challenge rely solely on accelerating operational speed, yet still face the challenge of keeping pace with rapid decorrelation caused by fast-varying components such as flowing red blood cells, leading to degraded focusing efficiency. To overcome this limitation, we propose a channel-selected WS (CS-WS) strategy that classifies scattering channels into slow-varying (extravascular tissue) and fast-varying (blood vessels) based on speckle decorrelation speed, optimizing only slow-varying channels while deactivating fast-varying ones. We validate CS-WS via in vivo experiments on live mouse ears using a fast closed-loop feedback system with a single iteration time of 4 ms. Results show that CS-WS achieves 38% faster convergence (398 vs. 642 iterations) and 27% higher focal enhancement (14.85 vs. 11.68) than conventional full-aperture WS. This simple approach provides a practical solution for dynamic in vivo scenarios, offering broad potential for robust deep-tissue optical focusing in biomedical applications.