Deep-skin third-harmonic generation(THG)imaging in vivo excited at the 2200 nm window  

作　　者：Xinlin Chen Yi Pan Ping Qiu Ke Wang 

机构地区：[1]Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University,Shenzhen 518060,P.R.China

出　　处：《Journal of Innovative Optical Health Sciences》2023年第4期58-65,共8页创新光学健康科学杂志（英文）

基　　金：supported by National Natural Science Foundation of China (NSFC) (Nos.61775143,61975126 and 62075135);the Science and Technology Innovation Commission of Shenzhen under Nos.JCYJ20190808174819083,JCYJ20190808175201640 and KQTD20150710165601017;China Postdoctoral Science Foundation (No.2021M702241).

摘　　要：The skin is heterogeneous and exerts strong scattering and aberration onto excitation light in multiphoton microscopy(MPM).Shifting to longer excitation wavelengths may help reduce skin scattering and aberration,potentially enabling larger imaging depths.However,previous demonstrations of skin MPM employ excitation wavelengths only up to the 1700 nm window,leaving an open question as to whether longer excitation wavelengths are suitable for deep-skin MPM.Here,in order to explore the longer-wavelength territory,first,we demonstrate characterization of the broadband transmittance of excised mouse skin,revealing a high transmittance window at 2200nm.Then,we demonstrate third-harmonic generation(THG)imaging in mouse skin in vivo excited at this window.With 9mW optical power on the skin surface operating at 1MHz repetition rate,we can get THG signals of 250
m below the skin surface.Comparative THG imaging excited at the 1700nm window shows that as imaging depth increases,THG signals decay even faster than those excited at 2200 nm.Our results thus uncover the 2200 nm window as a new,promising excitation window potential for deep-skin MPM.

关 键 词：Third-harmonic generation 2200 nm 1700 nm SKIN 

分 类 号：R318[医药卫生—生物医学工程]