Accurate knowledge of the internal core distribution of multicore fibres(MCFs)is essential,given their widespread application,including in fibre splicing,bundle fan-in/fan-out,mode coupling,writing gratings,and fibre ...Accurate knowledge of the internal core distribution of multicore fibres(MCFs)is essential,given their widespread application,including in fibre splicing,bundle fan-in/fan-out,mode coupling,writing gratings,and fibre drawing.However,the extensive use of MCFs is restricted by the limited methods available to precisely measure the fibre core distribution,as the measurement accuracy determines the performance of the product.In this study,a side-view and nondestructive scheme based on Bessel beam illumination was proposed for measuring the internal core distribution of a seven-core fibre.Bessel beams offer a large focal length in a scattering medium,and exhibit a unique pattern when propagating in an off-axis medium with a spatially varying refractive index.The results revealed that a long focal length and unique pattern influence the image contrast in the case of Bessel beams,which differs from a typical Gaussian beam.Further,high-precision measurement of a seven-core fibre core distribution based on a Bessel beam was demonstrated using a digital correlation method.A deep learning approach was used to improve the measurement precision to 0.2°with an accuracy of 96.8%.The proposed side-view Bessel-beam-based method has the potential to handle more complex MCFs and photonic crystal fibres.展开更多
The fluorescence from the out-of-focus region excited by the sidelobes of a Bessel beam is the major concern for light-sheet fluorescence microscopy （LSFM） with Bessel beam plane illumination. Here, we propose a met...The fluorescence from the out-of-focus region excited by the sidelobes of a Bessel beam is the major concern for light-sheet fluorescence microscopy （LSFM） with Bessel beam plane illumination. Here, we propose a method of applying the subtractive imaging to overcome the limitation of the conventional LSFM with Bessel beam plane illumination. In the proposed method, the sample is imaged twice by line scanning using the extended solid Bessel beam and the ring-like Bessel beam. By subtracting between the two images with similar out-of-focus blur, the improved image quality with the suppression of the Bessel beam sidelobes and enhanced sectioning ability with improved contrast are demonstrated.展开更多
基金sponsored by the Key Research and Development Program of Jiangsu Province,China(Grant No.BE2020113)the National Natural Science Foundation of China(61925502 and 62135007).
文摘Accurate knowledge of the internal core distribution of multicore fibres(MCFs)is essential,given their widespread application,including in fibre splicing,bundle fan-in/fan-out,mode coupling,writing gratings,and fibre drawing.However,the extensive use of MCFs is restricted by the limited methods available to precisely measure the fibre core distribution,as the measurement accuracy determines the performance of the product.In this study,a side-view and nondestructive scheme based on Bessel beam illumination was proposed for measuring the internal core distribution of a seven-core fibre.Bessel beams offer a large focal length in a scattering medium,and exhibit a unique pattern when propagating in an off-axis medium with a spatially varying refractive index.The results revealed that a long focal length and unique pattern influence the image contrast in the case of Bessel beams,which differs from a typical Gaussian beam.Further,high-precision measurement of a seven-core fibre core distribution based on a Bessel beam was demonstrated using a digital correlation method.A deep learning approach was used to improve the measurement precision to 0.2°with an accuracy of 96.8%.The proposed side-view Bessel-beam-based method has the potential to handle more complex MCFs and photonic crystal fibres.
基金supported by the National Natural Science Foundation of China(Nos.61665006,61661028,61565012,and 61378062)the Natural Science Foundation of Jiangxi Province(Nos.20161BAB212041,20162BCB23012,and 20171ACB21018)
文摘The fluorescence from the out-of-focus region excited by the sidelobes of a Bessel beam is the major concern for light-sheet fluorescence microscopy （LSFM） with Bessel beam plane illumination. Here, we propose a method of applying the subtractive imaging to overcome the limitation of the conventional LSFM with Bessel beam plane illumination. In the proposed method, the sample is imaged twice by line scanning using the extended solid Bessel beam and the ring-like Bessel beam. By subtracting between the two images with similar out-of-focus blur, the improved image quality with the suppression of the Bessel beam sidelobes and enhanced sectioning ability with improved contrast are demonstrated.
