Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity siz...Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity sizes.In the last decade,ultrasonic sensors with on-chip microcavities have been extensively developed;however,they are unsuitable for the near-field photoacoustic microscopy of micro/nanoscale objects in complex biological environments and endoscopic imaging.In this work,we developed ultrasonic sensors using two types of encapsulated microsphere resonators with different cavity materials.A noise equivalent pressure of as low as 160 Pa at 20 MHz was achieved with the acoustic response up to 70 MHz at-6 d B.Furthermore,the microsensor was used for photoacoustic microscopy in which we successfully performed 3 D imaging of hairs and leaf veins.The microsphere ultrasonic sensor has considerable potential as a probe-type ultrasonic detector for near-field photoacoustic microscopy of micro/nanoscale objects such as subcellular structures and high-resolution endoscopic photoacoustic imaging with its high sensitivity and wide bandwidth.展开更多
Optical ultrasonic probes,exemplified by Fabry–Perot cavities on optical fibers,have small sizes,high sensitivity,and pure optical characteristics,making them highly attractive in high-resolution ultrasonic/photoacou...Optical ultrasonic probes,exemplified by Fabry–Perot cavities on optical fibers,have small sizes,high sensitivity,and pure optical characteristics,making them highly attractive in high-resolution ultrasonic/photoacoustic imaging,especially in near-field or endoscopic scenarios.Taking a different approach,we demonstrate an ultrasensitive and broadband ultrasound microprobe formed by an optical whispering-gallery-mode polymer microcavity coupled to a U-shaped microfiber.With the h/√igh-quality(Q)factors(>10^(6)),the noise equivalent pressure of the ultrasound microprobe reaches 1.07 m Pa∕Hz with a record broadband response of 150 MHz and a large detection angle of 180°.Our results show that this optical microprobe can overcome the strong decay resulting from ultrasound diverging and medium absorption through short working distances.We further demonstrate high-quality in vivo whole-body photoacoustic imaging of a zebrafish larva.Our implementation provides a new strategy for developing miniature ultrasound detectors and holds great potential for broad applications.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2017YFE0104200)National Natural Science Foundation of China(Grant Nos.81421004,62105006)supported by the China Postdoctoral Science Foundation(Grant Nos.2020M680187,2021T140023)。
文摘Optical whispering-gallery microresonators have attracted considerable interest for ultrasensitive ultrasound detection and photoacoustic imaging because of the combination of high quality factors and small cavity sizes.In the last decade,ultrasonic sensors with on-chip microcavities have been extensively developed;however,they are unsuitable for the near-field photoacoustic microscopy of micro/nanoscale objects in complex biological environments and endoscopic imaging.In this work,we developed ultrasonic sensors using two types of encapsulated microsphere resonators with different cavity materials.A noise equivalent pressure of as low as 160 Pa at 20 MHz was achieved with the acoustic response up to 70 MHz at-6 d B.Furthermore,the microsensor was used for photoacoustic microscopy in which we successfully performed 3 D imaging of hairs and leaf veins.The microsphere ultrasonic sensor has considerable potential as a probe-type ultrasonic detector for near-field photoacoustic microscopy of micro/nanoscale objects such as subcellular structures and high-resolution endoscopic photoacoustic imaging with its high sensitivity and wide bandwidth.
基金China Postdoctoral Science Foundation(2021T140023,2020M680187)National Natural Science Foundation of China(62105006,81421004)National Key Research and Development Program of China(2017YFE0104200)。
文摘Optical ultrasonic probes,exemplified by Fabry–Perot cavities on optical fibers,have small sizes,high sensitivity,and pure optical characteristics,making them highly attractive in high-resolution ultrasonic/photoacoustic imaging,especially in near-field or endoscopic scenarios.Taking a different approach,we demonstrate an ultrasensitive and broadband ultrasound microprobe formed by an optical whispering-gallery-mode polymer microcavity coupled to a U-shaped microfiber.With the h/√igh-quality(Q)factors(>10^(6)),the noise equivalent pressure of the ultrasound microprobe reaches 1.07 m Pa∕Hz with a record broadband response of 150 MHz and a large detection angle of 180°.Our results show that this optical microprobe can overcome the strong decay resulting from ultrasound diverging and medium absorption through short working distances.We further demonstrate high-quality in vivo whole-body photoacoustic imaging of a zebrafish larva.Our implementation provides a new strategy for developing miniature ultrasound detectors and holds great potential for broad applications.
