Hybrid optical parametrically oscillating emitter-enabled photoacoustic imaging of water:enhanced contrast,dynamic range,and multifaceted applications  

作　　者：Huajun Tang Yitian Tong Mingsheng Li Najia Sharmin Jiawei Shi Bingfeng Li Chandra Jinata Nikki Pui-Yue Lee Kevin K.Tsia Kenneth K.Y.Wong 

机构地区：[1]The University of Hong Kong,Department of Electrical and Electronic Engineering,Hong Kong,China [2]The University of Hong Kong,Department of Surgery,Li Ka Shing Faculty of Medicine,Hong Kong,China [3]Advanced Biomedical Instrumentation Centre,Hong Kong,China

出　　处：《Advanced Photonics Nexus》2024年第4期136-151,共16页先进光子学通讯（英文）

基　　金：supported by the Research Grants Council of the Hong Kong Special Administrative Region(SAR)of China(Grant Nos.HKU 17210522,HKU C7074-21G,HKU 17205321,and HKU 17200219);ITF MHKJFS Projects(Grant Nos.MHP/073/20 and MHP/057/21);the Health@InnoHK Program of the Innovation and Technology Commission of the Hong Kong SAR Government.

摘　　要：Water photoacoustic microscopy(PAM)enables water absorption contrast mapping in deep biological tissue,which further allows a more detailed architecture analysis and facilitates a better understanding of metabolic and pathophysiological pathways.The strongest absorption peak of water in the near-infrared region occurs at 1930 nm,where the first overtone of the O-H bond lies.However,general light sources operating in this band hitherto still suffer from low optical signal-to-noise ratio and suboptimal pulse widths for photoacoustic signal generation.These lead to not only PAM contrast deterioration but also a high risk of sample photodamage.Consequently,we developed a hybrid optical parametrically-oscillating emitter(HOPE)source for an improved water PAM image contrast,leading to noninvasive and safer bioimaging applications.Our proposed source generates 1930 nm laser pulses with high spectral purity at a repetition rate of 187.5 kHz.The pulse width is flexibly tunable from 4 to 15 ns,and the maximum pulse energy is 700 nJ with a power stability of 1.79%.Leveraging these advancements,we also demonstrated high-contrast water PAM in multifaceted application scenarios,including tracking the dynamic of water distribution in a zebrafish embryo,visualizing the water content of a murine tumor xenograft,and mapping the fluid distribution in an edema mouse ear model.Finally,we showcased 1750-nm/1930-nm dual-color PAM for quantitative imaging of lipid and water distributions with reduced cross talk and imaging artifacts.Given all these results,we believe that our HOPE source can heighten water PAM’s relevance in both biological research and clinical diagnostics.

关 键 词：photoacoustic microscopy WATER optical parameter near-infrared region 

分 类 号：TN2[电子电信—物理电子学]