Optical-resolution photoacoustic microscopy (OR-PAM) has demonstrated high-spatial-resolution imaging of optical absorption in biological tissue. To date, most OR-PAM systems rely on mechanical scanning with confocally aligned optical excitation and ultrasonic detection, limiting the wide-field imaging speed of these systems. Although several multifocal OR-PA (MFOR-PA) systems have attempted to address this limitation, they are hindered by the complex design in a constrained physical space. Here, we present a two-dimensional (2D) MFOR-PAM system that utilizes a 2D microlens array and an acoustic ergodic relay. Using a single-element ultrasonic transducer, this system can detect PA signals generated from 400 optical foci in parallel and then raster scan the optical foci patterns to form an MFOR-PAM image. This system improves the imaging resolution of an acoustic ergodic relay system from 220 to 13 μm and enables 400-folds shorter scanning time than that of a conventional OR-PAM system at the same resolution and laser repetition rate. We demonstrated the imaging ability of the system with both in vitro and in vivo experiments.

光学分辨率光声显微镜（OR-PAM）已经证明了生物组织中光吸收的高空间分辨率成像。迄今为止，大多数 OR-PAM 系统依赖于具有共焦对准光学激发和超声波检测的机械扫描，限制了这些系统的宽视场成像速度。尽管一些多焦点 OR-PA (MFOR-PA) 系统试图解决这一限制，但它们受到物理空间有限的复杂设计的阻碍。在这里，我们提出了一种二维 (2D) MFOR-PAM 系统，该系统利用 2D 微透镜阵列和声学遍历中继。该系统使用单元件超声换能器，可以并行检测 400 个光学焦点生成的 PA 信号，然后对光学焦点图案进行光栅扫描以形成 MFOR-PAM 图像。该系统将声学遍历中继系统的成像分辨率从 220 μm 提高到 13 μm，并且在相同分辨率和激光重复率下，扫描时间比传统 OR-PAM 系统缩短 400 倍。我们通过体外和体内实验证明了该系统的成像能力。