High-Sensitivity Optical-Resolution Photoacoustic Microscopy with an Optical-Acoustic Combiner Based on an Off-Axis Parabolic Acoustic Mirror

Xiang Zhang,Jie Yin,Xiaojun Liu,Zizhong Hu,Chao Tao,Songtao Yuan,Yang Liu,Qinghuai Liu

doi:10.3390/photonics8040127

Abstract

Optical-resolution photoacoustic microscopy (OR-PAM) is a promising noninvasive biomedical imaging technology with label-free optical absorption contrasts. Performance of OR-PAM is usually closely related to the optical-acoustic combiner. In this study, we propose an optical-acoustic combiner based on a flat acoustic reflector and an off-axis parabolic acoustic mirror with a conical bore. Quantitative simulation and experiments demonstrated that this combiner can provide better acoustic focusing performance and detection sensitivity. Moreover, OR-PAM is based on the combiner suffer low optical disorders, which guarantees the good resolution. In vivo experiments of the mouse brain and the iris were also conducted to show the practicability of the combiner in biomedicine. This proposed optical-acoustic combiner realizes a high-quality optical-acoustic confocal alignment with minimal optical disorders and acoustic insertion loss, strong acoustic focusing, and easy implementation. These characteristics might be useful for improving the performance of OR-PAM.

Highlights

Photoacoustic (PAI) imaging is a promising noninvasive biomedical imaging technology and has been rapidly developed in recent years [1,2,3,4,5,6,7,8]
We propose an optical-acoustic combiner composed of a flat acoustic reflector and an off-axis parabolic acoustic mirror (OPM) with a conical bore
Combiner Based on the OPM

Summary

Introduction

Photoacoustic (PAI) imaging is a promising noninvasive biomedical imaging technology and has been rapidly developed in recent years [1,2,3,4,5,6,7,8]. Optical-resolution photoacoustic microscopy (OR-PAM) is one form of the PAI inheriting its characteristics and is useful in both preclinical and clinical research [9]. OR-PAM could achieve images with a resolution of micron-scale or even submicron-scale level and a penetration depth of up to one millimeter [13]. It is unique among optical microscopy technologies for its label-free detection of optical absorption with a relative sensitivity of 100% [14]. OR-PAM has shown great potentials in various biomedical applications, such as brain imaging [2,5,15,16], breast cancer imaging [3], animal embryo imaging [4,17], cell imaging [18,19,20], and microcirculation imaging [6,21,22,23,24,25,26,27,28,29,30]

Methods

Results

Conclusion