2023/04/04 by Tengfei Wu, Yixuan Zhang, Wu, Tengfei +9
Engineering · Physics and Astronomy · #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Optical Coherence Tomography Applications #Optics (physics.optics) #Photoacoustic and Ultrasonic Imaging #Random lasers and scattering media
paper · pdf · doi:10.48550/arxiv.2304.01759
openalex publication_date 2023/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Aberrations and multiple scattering in biological tissues critically distort light beams into highly complex speckle patterns. In this regard, digital optical phase conjugation (DOPC) is a promising technique enabling in-depth focusing. However, DOPC becomes challenging when using fluorescent guide-stars for four main reasons: The low photon budget available, the large spectral bandwidth of the fluorescent signal, the Stokes shift between the emission and the excitation wavelength, and the absence of reference beam preventing holographic measurement. Here, we demonstrate the possibility to focus a laser beam through multiple-scattering samples by measuring speckle fields in a single acquisition step with a reference-free, high-resolution wavefront sensor. By taking advantage of the large spectral bandwidth of forward multiply scattering samples, Digital Fluorescence Phase Conjugation (DFPC) is achieved to focus a laser beam at the excitation wavelength while measuring the broadband speckle field arising from a micron-sized fluorescent bead.