Extending the depth of field(DOF)is essential for large-volume imaging in biological research,particularly in thick tissue environments.Bessel beams and their variants are widely used due to their simplicity and have ...Extending the depth of field(DOF)is essential for large-volume imaging in biological research,particularly in thick tissue environments.Bessel beams and their variants are widely used due to their simplicity and have been successfully applied to in vivo imaging.A recent advancement demonstrated the application of droplet Bessel beams(DBBs)for multi-photon microscopy,enabling functional imaging in live mouse brains.However,DBB generation inevitably requires active phase switching devices such as spatial light modulators,which reduce imaging speed and increase system complexity.This study introduces a droplet Bessel beam metalens(DBBM)that passively generates DBBs without phase switching by employing rectangular meta-atoms for orthogonal polarization modulation and X-shaped meta-atoms for amplitude control.Optical simulations identify optimal DBBM parameters that maximize the point spread function(PSF)aspect ratio while minimizing energy leakage into side lobes.Furthermore,the fabricated DBBM produces PSFs consistent with simulations.Imaging simulations based on three-dimensional confocal images of expansion microscopy-treated organoids demonstrated that the DBBM maintains superior performance even in the presence of aberrations.These findings establish the DBBM as a compact and passive solution for extended DOF imaging without the need for beam-shaping devices.Metalens technology is anticipated to have broad applications in real-time volumetric bioimaging and enable simplified optical system designs.展开更多
Image scanning microscopy(ISM)is a promising imaging technique that offers sub-diffraction-limited resolution and optical sectioning.Theoretically,ISM can improve the optical resolution by a factor of two through pixe...Image scanning microscopy(ISM)is a promising imaging technique that offers sub-diffraction-limited resolution and optical sectioning.Theoretically,ISM can improve the optical resolution by a factor of two through pixel reassignment and deconvolution.Multifocal array illumination and scanning have been widely adopted to implement ISM because of their simplicity.Conventionally,digital micromirror devices(DMDs)1 and microlens arrays(MLAs)2,3 have been used to generate dense and uniform multifocal arrays for ISM,which are critical for achieving fast imaging and high-quality ISM reconstruction.However,these approaches have limitations in terms of cost,numerical aperture(NA),pitch,and uniformity,making it challenging to create dense and high-quality multifocal arrays at high NA.To overcome these limitations,we introduced a novel multifocal metalens design strategy called the hybrid multiplexing method,which combines two conventional multiplexing approaches:phase addition and random multiplexing.Through numerical simulations,we demonstrate that the proposed method generates more uniform and denser multifocal arrays than conventional methods,even at small pitches.As a proof of concept,we fabricated a multifocal metalens generating 40×40 array of foci with a 3μm pitch and NA of 0.7 operating at a wavelength of 488 nm and then constructed the multifocal metalens-based ISM(MMISM).We demonstrated that MMISM successfully resolved sub-diffraction-limited features in imaging of microbead samples and forebrain organoid sections.The results showed that MMISM imaging achieved twice the diffraction-limited resolution and revealed clearer structural features of neurons compared to wide-field images.We anticipate that our novel design strategy can be widely applied to produce multifunctional optical elements and replace conventional optical elements in specialized applications.展开更多
基金supported by the Samsung Research Funding&Incubation Center of Samsung Electronics under Project Number SRFC-IT2401-01by National Research Foundation(NRF)grants(RS-2024-00462912 and RS-2023-00266110)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe NRF Sejong Science Fellowship(RS-2021-NR061797)funded by the MSIT of the Korean government.
文摘Extending the depth of field(DOF)is essential for large-volume imaging in biological research,particularly in thick tissue environments.Bessel beams and their variants are widely used due to their simplicity and have been successfully applied to in vivo imaging.A recent advancement demonstrated the application of droplet Bessel beams(DBBs)for multi-photon microscopy,enabling functional imaging in live mouse brains.However,DBB generation inevitably requires active phase switching devices such as spatial light modulators,which reduce imaging speed and increase system complexity.This study introduces a droplet Bessel beam metalens(DBBM)that passively generates DBBs without phase switching by employing rectangular meta-atoms for orthogonal polarization modulation and X-shaped meta-atoms for amplitude control.Optical simulations identify optimal DBBM parameters that maximize the point spread function(PSF)aspect ratio while minimizing energy leakage into side lobes.Furthermore,the fabricated DBBM produces PSFs consistent with simulations.Imaging simulations based on three-dimensional confocal images of expansion microscopy-treated organoids demonstrated that the DBBM maintains superior performance even in the presence of aberrations.These findings establish the DBBM as a compact and passive solution for extended DOF imaging without the need for beam-shaping devices.Metalens technology is anticipated to have broad applications in real-time volumetric bioimaging and enable simplified optical system designs.
基金supported by the Samsung Research Funding&Incubation Center of Samsung Electronics under Project Number SRFC-IT2401-01 and by National Research Foundation(NRF)grants(RS-2024-00462912,RS-2023-00266110,and RS-2020-NR049544)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentI.K.acknowledges the NRF Sejong Science Fellowship(RS-2021-NR061797)funded by the MSIT of the Korean government.
文摘Image scanning microscopy(ISM)is a promising imaging technique that offers sub-diffraction-limited resolution and optical sectioning.Theoretically,ISM can improve the optical resolution by a factor of two through pixel reassignment and deconvolution.Multifocal array illumination and scanning have been widely adopted to implement ISM because of their simplicity.Conventionally,digital micromirror devices(DMDs)1 and microlens arrays(MLAs)2,3 have been used to generate dense and uniform multifocal arrays for ISM,which are critical for achieving fast imaging and high-quality ISM reconstruction.However,these approaches have limitations in terms of cost,numerical aperture(NA),pitch,and uniformity,making it challenging to create dense and high-quality multifocal arrays at high NA.To overcome these limitations,we introduced a novel multifocal metalens design strategy called the hybrid multiplexing method,which combines two conventional multiplexing approaches:phase addition and random multiplexing.Through numerical simulations,we demonstrate that the proposed method generates more uniform and denser multifocal arrays than conventional methods,even at small pitches.As a proof of concept,we fabricated a multifocal metalens generating 40×40 array of foci with a 3μm pitch and NA of 0.7 operating at a wavelength of 488 nm and then constructed the multifocal metalens-based ISM(MMISM).We demonstrated that MMISM successfully resolved sub-diffraction-limited features in imaging of microbead samples and forebrain organoid sections.The results showed that MMISM imaging achieved twice the diffraction-limited resolution and revealed clearer structural features of neurons compared to wide-field images.We anticipate that our novel design strategy can be widely applied to produce multifunctional optical elements and replace conventional optical elements in specialized applications.
