Photoacoustic imaging has many advantages in ophthalmic application including high-resolution,requirement of no exogenous contrast agent,and noninvasive acquisition of both morphologic and functional information.Howev...Photoacoustic imaging has many advantages in ophthalmic application including high-resolution,requirement of no exogenous contrast agent,and noninvasive acquisition of both morphologic and functional information.However,due to the limited depth of focus of the imaging method and large curvature of the eye,it remains a challenge to obtain high quality vascular image of entire anterior segment.Here,we proposed a new method to achieve high quality imaging of anterior segment.The new method applied a curvature imaging strategy based on only one time scanning,and hence is time efficient and more suitable for ophthalmic imaging compared to previously reported methods using similar strategy.A custom-built photoacoustic imaging system was adapted for ophthalmic application and a customized image processing method was developed to quantitatively analyze both morphologic and functional information in vasculature of the anterior segment.The results showed that the new method improved the image quality of anterior segment significantly compared to that of conventional high resolution photoacoustic imaging.More importantly,we applied the new method to study ophthalmic disease in an in vivo mouse model for the first time.The results verified the suitability and advantages of the new method for imaging the entire anterior segment and the numerous potentials of applying it in ophthalmic imaging in future.展开更多
Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses...Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses present promising candidates for achieving this functionality.However,current multiplexing meta-lenses lack spectral modulation,and crosstalk between different wavelengths hampers the imaging quality,especilly for biological samples requiring precise wavelength specificity.Here,we experimentally demonstrate the nonlocal Huygens'meta-lens for high-quality-factor spin-multiplexing imaging.Quasi-bound states in the continuum(q-BlCs)are excited to provide a high quality factor of 90 and incident-angle dependence.The generalized Kerker condition,driven by Fano-like interactions between q-BIC and in-plane Mie resonances,breaks the radiation symmetry,resulting in a transmission peak with a geometric phase for polarization-converted light,while unconverted light exhibits a transmission dip without a geometric phase.Enhanced polarization conversion efficiency of 65%is achieved,accompanied by a minimal unconverted value,surpassing the theoretical limit of traditional thin nonlocal metasurfaces.Leveraging these effects,the output polarization-converted state exhibits an efficient wavelengthselective focusing phase profle.The unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion,passing high-frequency edge details.Bright-field imaging and edge detection are thus presented under two output spin states.This work provides a versatile framework for nonlocal metasurfaces,boosting biomedical imaging and sensing applications.展开更多
基金financial supports from the National Natural Science Foundation of China(NSFC)(Grants No.91739117,31570952,81873919,81371662 and 81927807)Shenzhen Science and Technology Innovation(Grant No.JCYJ20170413153129570)+1 种基金Beijing Natural Science Foundation of China(Grant No.3122010)。
文摘Photoacoustic imaging has many advantages in ophthalmic application including high-resolution,requirement of no exogenous contrast agent,and noninvasive acquisition of both morphologic and functional information.However,due to the limited depth of focus of the imaging method and large curvature of the eye,it remains a challenge to obtain high quality vascular image of entire anterior segment.Here,we proposed a new method to achieve high quality imaging of anterior segment.The new method applied a curvature imaging strategy based on only one time scanning,and hence is time efficient and more suitable for ophthalmic imaging compared to previously reported methods using similar strategy.A custom-built photoacoustic imaging system was adapted for ophthalmic application and a customized image processing method was developed to quantitatively analyze both morphologic and functional information in vasculature of the anterior segment.The results showed that the new method improved the image quality of anterior segment significantly compared to that of conventional high resolution photoacoustic imaging.More importantly,we applied the new method to study ophthalmic disease in an in vivo mouse model for the first time.The results verified the suitability and advantages of the new method for imaging the entire anterior segment and the numerous potentials of applying it in ophthalmic imaging in future.
基金supported by the University Grants Committee/Research Grants Council of the Hong Kong Special Administrative Region,China[Project No.AoE/P-502/20,CRF Project:C5031-22G,GRF Project:CityU15303521,CityU11305223,CityU11300224]City University of Hong Kong[Project No.9380131 and 7005867]+3 种基金National Natural Science Foundation of China[Grant No.62375232]S.X.acknowledges financial support from National Natural Science Foundation of China(Grant Nos.62125501,and 6233000076)Fundamental Research Funds for the Central Universities(Grant No.2022FRRK030004)Shenzhen Fundamental Research Projects(Grant Nos.JCYJ20220818102218040).
文摘Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological imaging.Multiplexing metalenses present promising candidates for achieving this functionality.However,current multiplexing meta-lenses lack spectral modulation,and crosstalk between different wavelengths hampers the imaging quality,especilly for biological samples requiring precise wavelength specificity.Here,we experimentally demonstrate the nonlocal Huygens'meta-lens for high-quality-factor spin-multiplexing imaging.Quasi-bound states in the continuum(q-BlCs)are excited to provide a high quality factor of 90 and incident-angle dependence.The generalized Kerker condition,driven by Fano-like interactions between q-BIC and in-plane Mie resonances,breaks the radiation symmetry,resulting in a transmission peak with a geometric phase for polarization-converted light,while unconverted light exhibits a transmission dip without a geometric phase.Enhanced polarization conversion efficiency of 65%is achieved,accompanied by a minimal unconverted value,surpassing the theoretical limit of traditional thin nonlocal metasurfaces.Leveraging these effects,the output polarization-converted state exhibits an efficient wavelengthselective focusing phase profle.The unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion,passing high-frequency edge details.Bright-field imaging and edge detection are thus presented under two output spin states.This work provides a versatile framework for nonlocal metasurfaces,boosting biomedical imaging and sensing applications.
