Scarring is one of the biggest areas of unmet need in the long-term success of glaucoma filtration surgery.Quantitative evaluation of the scar tissue and the post-operative structure with micron scale resolution facil...Scarring is one of the biggest areas of unmet need in the long-term success of glaucoma filtration surgery.Quantitative evaluation of the scar tissue and the post-operative structure with micron scale resolution facilitates development of anti-fibrosis techniques.However,the distinguishment of conjunctiva,sclera and the scar tissue in the surgical area still relies on pathologists'experience.Since polarized light imaging is sensitive to anisotropic properties of the media,it is ideal for discrimination of scar in the subconjunctival and episcleral area by characterizing small differences between proportion,organization and the orientation of the fibers.In this paper,we defined the conjunctiva,sclera,and the scar tissue as three target tissues after glaucoma filtration surgery and obtained their polarization characteristics from the tissue sections by a Mueller matrix microscope.Discrimination score based on parameters derived from Mueller matrix and machine learning was calculated and tested as a diagnostic index.As a result,the discrimination score of three target tissues showed significant difference between each other(p<0.001).The visualization of the discrimination results showed significant contrast between target tissues.This study proved that Mueller matrix imaging is effective in ocular scar discrimination and paves the way for its application on other forms of ocular fibrosis as a substitute or supplementary for clinical practice.展开更多
We developed a model to describe polarized photon scattering in biological tissues.In this model,tissues are simplified to a mixture of scatterers and surrounding mpdium.There are t wo types ofscatterers in the model:...We developed a model to describe polarized photon scattering in biological tissues.In this model,tissues are simplified to a mixture of scatterers and surrounding mpdium.There are t wo types ofscatterers in the model:solid spheres and infinitely long solid cylinders.Variables related to thescatterers include:the densities and sizes of the spheres and cylinders,the orientation and angulardistribution of cylinders.Variables related to the surrounding medium include:the refractiveindex,absorption coeficient and birefringence.In this paper,as a development we introduce anoptical activity effct to the model.By comparing experiments and Monte Carlo simulations,we analyze the backscater ing Mueller matrix patterms of several tissue-like media,and summarizethe different effects coming from anisotropic scattering and optical properties.In addition,wepropose a possible method to extract the optical activity values for tissues.Both the experimentaland simulated results show that,by analyzing the Mueller matrix patterns,the microstructureand optical properties of the medium can be obtained.The characteristic features of Muellermatrix patterns are potentilly powerful tools for studying the contrast mechanisms of polari-zation imaging for medical diagnosis.展开更多
We propose and conduct both the rotating linear polarization imaging(RLPI)and Mueller matrix transformation(MMT)measurements of different biological tissue samples,and testify the capability of the Mueller matrix pola...We propose and conduct both the rotating linear polarization imaging(RLPI)and Mueller matrix transformation(MMT)measurements of different biological tissue samples,and testify the capability of the Mueller matrix polarimetry for the anisotropic scattering media.The independent parameters extracted from the RLPI and MMT techniques are compared and analyzed.The tissue experimental results show that the parameters are closely related to the structural characteristics of the turbid scattering media,including the sizes of the scatterers,the angular distribution and order of alignment of thefibers.The results and conclusions in this paper may provide a potential method for the detection of precancerous and early stage cancerous tissues.Also,such studies represent the Mueller matrix transformation procedure which results in a set of parameters linking up the Mueller matrix elements to the structural and optical properties of the media.展开更多
Birefringence （polarization-related phase-shift）, polarization dependent gain （PDG） and mode coupling are three factors that may synchronously influence the transmission of single-wavelength polarized light in opt...Birefringence （polarization-related phase-shift）, polarization dependent gain （PDG） and mode coupling are three factors that may synchronously influence the transmission of single-wavelength polarized light in optical fibers. This paper obtains a new Mueller matrix analysis, which can be used under conditions that all these three factors are existing and changing. According to our transmission model, the state of polarization （SOP） changes along an optical mierostructure fiber with co-existence of birefringence-PDG-mode coupling were simulated. The simulated results, which show the phenomena of SOP constringency, are in good agreement with previous theoretical analyses.展开更多
Mueller matrix elements are presented represen ting scatter to 90° from an incident polarized laser beam. The cases considered include five particle sizes (such as l.24 μm, 0.494 μm, 0.36 μm, 0.123 μm, and 0....Mueller matrix elements are presented represen ting scatter to 90° from an incident polarized laser beam. The cases considered include five particle sizes (such as l.24 μm, 0.494 μm, 0.36 μm, 0.123 μm, and 0.065 μm), two concentr ations (such as 0.002 5% and 0.005% by volume), and three detector depths (such as 0, l.5 cm, and 3 cm into the scat tering volume). If the magnitudes of the elements can be rounded off to the near est 0.01, a particle size dependence is described by the resulting average mat rices, which is only two matrices for d >0.22 μm and d <0.22 μm which are nonsingular and asymmetric, respectively.展开更多
Mueller matrix ellipsometry(MME)provides the 4×4 Mueller matrix of a sample under test,which determines how the state of polarization is changed as light interacts with the sample.Due to the redundant information...Mueller matrix ellipsometry(MME)provides the 4×4 Mueller matrix of a sample under test,which determines how the state of polarization is changed as light interacts with the sample.Due to the redundant information contained in the Mueller matrix,MME has gained more and more extensive applications in the characterization of surfaces,interfaces,thin films,and nanostructures.In addition,the instrumentation of MME has also achieved great developments since its advent in the 1970 s.In this paper,we will first review the basic principle as well as the common system layouts of MME for the full Mueller matrix measurement.Then,the basic procedure of ellipsometry data analysis is reviewed.After that,some new developments in MME in our lab for different applications are introduced,including the broadband MME,the high-resolution imaging MME,and the high-speed MME.Some emerging applications of the developed MMEs are also presented.Conclusions and perspectives of the advanced ellipsometry are finally drawn and discussed.展开更多
Polarization underwater imaging is of great potential to target detection in turbid water. Typical methods are challenged by the requirement on degrees of polarization(Do Ps) of both target light and backscattering. A...Polarization underwater imaging is of great potential to target detection in turbid water. Typical methods are challenged by the requirement on degrees of polarization(Do Ps) of both target light and backscattering. A polarization descattering imaging method was developed using the Mueller matrix, which in turn derived a depolarization(Dep) index from the Mueller matrix to characterize scattering media by estimating the transmittance map by combining a developed optimal function.By quantifying light attenuation with the transmittance map, a clear vision of targets can be recovered. Only using the information of scattering media, the underwater vision under diverse water turbidity was enhanced by the results of experimental data.展开更多
A ferroelectric liquid crystal polarization rotator(FLCPR)has been widely used in polarization measurement due to its fast and stable modulation characteristics.The accurate characterization of the modulation performa...A ferroelectric liquid crystal polarization rotator(FLCPR)has been widely used in polarization measurement due to its fast and stable modulation characteristics.The accurate characterization of the modulation performance of FLCPR directly affects the measurement accuracy of the instrument based on liquid crystal modulation.In this study,FLCPR is accurately characterized using a self-developed high-speed Stokes polarimeter.Strong linear and weak circular birefringence are observed during modulation processes,and all the optical parameters of FLCPR are dependent on driving voltage.A dual FLCPR-based Mueller matrix polarimeter is designed on the basis of the Stokes polarimeter.The designed polarimeter combines the advantages of the high modulation frequency of FLCPR and the ultrahigh temporal resolution of the fast polarization measurement system in the Stokes polarimeter.The optimal configuration of the designed polarizer is predicted in accordance with singular value decomposition.A simulated thickness measurement of a 24 nm standard SiO2 thin film is performed using the optimal configuration.Results show that the relative error in thickness measurement caused by using the unsatisfactory modulation characteristics of FLCPR reaches up to−4.34%.This finding demonstrates the importance of the accurate characterization of FLCPR in developing a Mueller matrix polarizer.展开更多
Mueller matrices were measured for natural （or reference） samples of human nails and samples irradiated by a 2 Gy ionizing radiation dose. The elements of the total Mueller matrix as a function of scattering angle w...Mueller matrices were measured for natural （or reference） samples of human nails and samples irradiated by a 2 Gy ionizing radiation dose. The elements of the total Mueller matrix as a function of scattering angle were measured in backscattering mode at a wavelength of 632.8 nm. Several types of depolarizing Mueller matrix decompositions, namely, Ossikovsky, Williams, and Chipman, were calculated as a function of scattering angle for each nail sample. A comparative analysis of the sensitivity of the Mueller matrix decompositions in relation to the problem of emergency dose assessment in nails was performed.展开更多
基金supported by the Natural Science Foundation of Beijing(No.7194266)Beijing Municipal Administration of Hospitals'Youth Program(No.QML20191206)+1 种基金Fundamental Research Funds for the Central Public Welfare Research Institutes(No.XTCX2021002)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(No.CI2021A00601).
文摘Scarring is one of the biggest areas of unmet need in the long-term success of glaucoma filtration surgery.Quantitative evaluation of the scar tissue and the post-operative structure with micron scale resolution facilitates development of anti-fibrosis techniques.However,the distinguishment of conjunctiva,sclera and the scar tissue in the surgical area still relies on pathologists'experience.Since polarized light imaging is sensitive to anisotropic properties of the media,it is ideal for discrimination of scar in the subconjunctival and episcleral area by characterizing small differences between proportion,organization and the orientation of the fibers.In this paper,we defined the conjunctiva,sclera,and the scar tissue as three target tissues after glaucoma filtration surgery and obtained their polarization characteristics from the tissue sections by a Mueller matrix microscope.Discrimination score based on parameters derived from Mueller matrix and machine learning was calculated and tested as a diagnostic index.As a result,the discrimination score of three target tissues showed significant difference between each other(p<0.001).The visualization of the discrimination results showed significant contrast between target tissues.This study proved that Mueller matrix imaging is effective in ocular scar discrimination and paves the way for its application on other forms of ocular fibrosis as a substitute or supplementary for clinical practice.
基金supported by National Natural Science China(NSFC)Foundation of Grants No.10974114,11174178,41106034Open Fund of Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes,Jinan University.
文摘We developed a model to describe polarized photon scattering in biological tissues.In this model,tissues are simplified to a mixture of scatterers and surrounding mpdium.There are t wo types ofscatterers in the model:solid spheres and infinitely long solid cylinders.Variables related to thescatterers include:the densities and sizes of the spheres and cylinders,the orientation and angulardistribution of cylinders.Variables related to the surrounding medium include:the refractiveindex,absorption coeficient and birefringence.In this paper,as a development we introduce anoptical activity effct to the model.By comparing experiments and Monte Carlo simulations,we analyze the backscater ing Mueller matrix patterms of several tissue-like media,and summarizethe different effects coming from anisotropic scattering and optical properties.In addition,wepropose a possible method to extract the optical activity values for tissues.Both the experimentaland simulated results show that,by analyzing the Mueller matrix patterns,the microstructureand optical properties of the medium can be obtained.The characteristic features of Muellermatrix patterns are potentilly powerful tools for studying the contrast mechanisms of polari-zation imaging for medical diagnosis.
基金This work was supported by the National Natural Science Foundation of China(NSFC)Grants No.10974114,11174178,41106034.
文摘We propose and conduct both the rotating linear polarization imaging(RLPI)and Mueller matrix transformation(MMT)measurements of different biological tissue samples,and testify the capability of the Mueller matrix polarimetry for the anisotropic scattering media.The independent parameters extracted from the RLPI and MMT techniques are compared and analyzed.The tissue experimental results show that the parameters are closely related to the structural characteristics of the turbid scattering media,including the sizes of the scatterers,the angular distribution and order of alignment of thefibers.The results and conclusions in this paper may provide a potential method for the detection of precancerous and early stage cancerous tissues.Also,such studies represent the Mueller matrix transformation procedure which results in a set of parameters linking up the Mueller matrix elements to the structural and optical properties of the media.
基金supported by the National Natural Science Foundation of China(Grants Nos.60877057 and 60907027)
文摘Birefringence （polarization-related phase-shift）, polarization dependent gain （PDG） and mode coupling are three factors that may synchronously influence the transmission of single-wavelength polarized light in optical fibers. This paper obtains a new Mueller matrix analysis, which can be used under conditions that all these three factors are existing and changing. According to our transmission model, the state of polarization （SOP） changes along an optical mierostructure fiber with co-existence of birefringence-PDG-mode coupling were simulated. The simulated results, which show the phenomena of SOP constringency, are in good agreement with previous theoretical analyses.
文摘Mueller matrix elements are presented represen ting scatter to 90° from an incident polarized laser beam. The cases considered include five particle sizes (such as l.24 μm, 0.494 μm, 0.36 μm, 0.123 μm, and 0.065 μm), two concentr ations (such as 0.002 5% and 0.005% by volume), and three detector depths (such as 0, l.5 cm, and 3 cm into the scat tering volume). If the magnitudes of the elements can be rounded off to the near est 0.01, a particle size dependence is described by the resulting average mat rices, which is only two matrices for d >0.22 μm and d <0.22 μm which are nonsingular and asymmetric, respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.51727809,52022034,62175075,and 52130504)the Key Research and Development Plan of Hubei Province(Grant Nos.2020BAA008 and 2021BAA013)。
文摘Mueller matrix ellipsometry(MME)provides the 4×4 Mueller matrix of a sample under test,which determines how the state of polarization is changed as light interacts with the sample.Due to the redundant information contained in the Mueller matrix,MME has gained more and more extensive applications in the characterization of surfaces,interfaces,thin films,and nanostructures.In addition,the instrumentation of MME has also achieved great developments since its advent in the 1970 s.In this paper,we will first review the basic principle as well as the common system layouts of MME for the full Mueller matrix measurement.Then,the basic procedure of ellipsometry data analysis is reviewed.After that,some new developments in MME in our lab for different applications are introduced,including the broadband MME,the high-resolution imaging MME,and the high-speed MME.Some emerging applications of the developed MMEs are also presented.Conclusions and perspectives of the advanced ellipsometry are finally drawn and discussed.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.62075175 and 62005203)the Key Laboratory of Optical Engineering,Chinese Academy of Sciences。
文摘Polarization underwater imaging is of great potential to target detection in turbid water. Typical methods are challenged by the requirement on degrees of polarization(Do Ps) of both target light and backscattering. A polarization descattering imaging method was developed using the Mueller matrix, which in turn derived a depolarization(Dep) index from the Mueller matrix to characterize scattering media by estimating the transmittance map by combining a developed optimal function.By quantifying light attenuation with the transmittance map, a clear vision of targets can be recovered. Only using the information of scattering media, the underwater vision under diverse water turbidity was enhanced by the results of experimental data.
基金This work was funded by the National Natural Science Foundation of China(Grant Nos.51575214,51525502,51975232,51727809,and 51805193)the National Key Research and Development Plan(Grant No.2017YFF0204705)+1 种基金the Natural Science Foundation of Hubei Province of China(Grant No.2018CFA057)the National Science and Technology Major Project of China(Grant No.2017ZX02101006-004).
文摘A ferroelectric liquid crystal polarization rotator(FLCPR)has been widely used in polarization measurement due to its fast and stable modulation characteristics.The accurate characterization of the modulation performance of FLCPR directly affects the measurement accuracy of the instrument based on liquid crystal modulation.In this study,FLCPR is accurately characterized using a self-developed high-speed Stokes polarimeter.Strong linear and weak circular birefringence are observed during modulation processes,and all the optical parameters of FLCPR are dependent on driving voltage.A dual FLCPR-based Mueller matrix polarimeter is designed on the basis of the Stokes polarimeter.The designed polarimeter combines the advantages of the high modulation frequency of FLCPR and the ultrahigh temporal resolution of the fast polarization measurement system in the Stokes polarimeter.The optimal configuration of the designed polarizer is predicted in accordance with singular value decomposition.A simulated thickness measurement of a 24 nm standard SiO2 thin film is performed using the optimal configuration.Results show that the relative error in thickness measurement caused by using the unsatisfactory modulation characteristics of FLCPR reaches up to−4.34%.This finding demonstrates the importance of the accurate characterization of FLCPR in developing a Mueller matrix polarizer.
文摘Mueller matrices were measured for natural （or reference） samples of human nails and samples irradiated by a 2 Gy ionizing radiation dose. The elements of the total Mueller matrix as a function of scattering angle were measured in backscattering mode at a wavelength of 632.8 nm. Several types of depolarizing Mueller matrix decompositions, namely, Ossikovsky, Williams, and Chipman, were calculated as a function of scattering angle for each nail sample. A comparative analysis of the sensitivity of the Mueller matrix decompositions in relation to the problem of emergency dose assessment in nails was performed.
