Laser diodes (LDs) have been considered as cost-effective and compact excitation sources to overcome the requirement of costly and bulky pulsed laser sources that are commonly used in photoacoustic microscopy (PAM). However, the spatial resolution and/or imaging speed of previously reported LD-based PAM systems have not been optimized simultaneously. In this paper, we developed a high-speed and high-resolution LD-based PAM system using a continuous wave LD, operating at a pulsed mode, with a repetition rate of 30 kHz, as an excitation source. A hybrid scanning mechanism that synchronizes a one-dimensional galvanometer mirror and a two-dimensional motorized stage is applied to achieve a fast imaging capability without signal averaging due to the high signal-to-noise ratio. By optimizing the optical system, a high lateral resolution of 4.8 μm has been achieved. In vivo microvasculature imaging of a mouse ear has been demonstrated to show the high performance of our LD-based PAM system.

中文翻译：

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高速高分辨率基于激光二极管的光声显微术，用于体内微血管成像

激光二极管（LD）被认为是具有成本效益的紧凑型激发源，可以克服光声显微镜（PAM）中常用的昂贵且笨重的脉冲激光源的需求。但是，以前报告的基于LD的PAM系统的空间分辨率和/或成像速度尚未同时优化。在本文中，我们开发了一种高速和高分辨率的基于LD的PAM系统，该系统使用连续波LD作为激励源，该连续波LD以脉冲模式工作，重复频率为30 kHz。由于高信噪比，采用了使一维检流计镜和二维电动平台同步的混合扫描机制，以实现快速成像能力而无需信号平均。通过优化光学系统，横向分辨率高达4。已经达到8μm。小鼠耳朵的体内微脉管系统成像已显示出我们基于LD的PAM系统的高性能。