Mueller Matrix Polarimetry Research Articles

Reflection mode polarimetry guides laser mass spectrometry to diagnostically important regions of human breast cancer tissue

To enhance the clinical utility of mass spectrometry (MS), lengthy dwell times on less informative regions of patient specimens (e.g., adipose tissue in breast) must be minimized. Additionally, a promising variant of MS known as picosecond infrared laser MS (PIRL-MS) faces further challenges, namely, lipid contamination when probing adipose tissue. Here we demonstrate on several thick non-sectioned resected human breast specimens (healthy and malignant) that reflection-mode polarimetric imaging can robustly guide PIRL-MS toward regions devoid of significant fat content to (1) avoid signal contamination and (2) shorten overall MS analysis times. Through polarimetric targeting of non-fat regions, PIRL-MS sampling revealed feature-rich spectral signatures including several known breast cancer markers. Polarimetric guidance mapping was enabled by circular degree-of-polarization (DOP) imaging via both Stokes and Mueller matrix polarimetry. These results suggest a potential synergistic hybrid approach employing polarimetry as a wide-field-imaging guidance tool to optimize efficient probing of tissue molecular content using MS.

Micro-Nanoparticle Characterization: Establishing Underpinnings for Proper Identification and Nanotechnology-Enabled Remediation.

Microplastics (MPLs) and nanoplastics (NPLs) are smaller particles derived from larger plastic material, polymerization, or refuse. In context to environmental health, they are separated into the industrially-created "primary" category or the degradation derivative "secondary" category where the particles exhibit different physiochemical characteristics that attenuate their toxicities. However, some particle types are more well documented in terms of their fate in the environment and potential toxicological effects (secondary) versus their industrial fabrication and chemical characterization (primary). Fourier Transform Infrared Spectroscopy (FTIR/µ-FTIR), Raman/µ-Raman, Proton Nuclear Magnetic Resonance (H-NMR), Curie Point-Gas Chromatography-Mass Spectrometry (CP-gc-MS), Induced Coupled Plasma-Mass Spectrometry (ICP-MS), Nanoparticle Tracking Analysis (NTA), Field Flow Fractionation-Multiple Angle Light Scattering (FFF-MALS), Differential Scanning Calorimetry (DSC), Thermogravimetry (TGA), Differential Mobility Particle [Sizing] (DMPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Scanning Transmission X-ray Microspectroscopy (STXM) are reviewed as part of a suite of characterization methods for physiochemical ascertainment and distinguishment. In addition, Optical-Photothermal Infrared Microspectroscopy (O-PTIR), Z-Stack Confocal Microscopy, Mueller Matrix Polarimetry, and Digital Holography (DH) are touched upon as a suite of cutting-edge modes of characterization. Organizations, like the water treatment or waste management industry, and those in groups that bring awareness to this issue, which are in direct contact with the hydrosphere, can utilize these techniques in order to sense and remediate this plastic polymer pollution. The primary goal of this review paper is to highlight the extent of plastic pollution in the environment as well as introduce its effect on the biodiversity of the planet while underscoring current characterization techniques in this field of research. The secondary goal involves illustrating current and theoretical avenues in which future research needs to address and optimize MPL/NPL remediation, utilizing nanotechnology, before this sleeping giant of a problem awakens.

Mueller matrix polarimetry approach for noninvasive glucose sensing with absorbance and anisotropic parameters on fingertips.

A Mueller matrix polarimetry system at 532 nm wavelength is developed for noninvasive glucose sensing in turbid media such as human's fingertip. The system extracts mean absorbance and anisotropic properties, demonstrated numerically and experimentally with phantom glucose samples. It is found that mean absorbance ( ), depolarization index (Δ), and linear dichroism (LD) show linear variation with glucose concentration 100-500 mg/dL. In addition, LightTools simulations indicate proportional scaling of scattering effects with , Δ, and LD. Real-world tests on fingertip show a strong correlation between these properties and blood glucose levels with a mean absolute relative deviation (MARD) of 12.56% and a correlation coefficient (R2) of 0.875 in prediction by a neural network (NN) model, highlighting the advantages of Mueller matrix in extracting more parameters related to blood glucose.

Combination of Muller matrix imaging polarimetry and artificial intelligence for classification of mice skin cancer tissue in-vitro and in-vivo

Mueller matrix imaging polarimetry is a fast and non-invasive technique for discriminating between different types of biological samples based on the characteristics of polarized light interacting with them. Combining Mueller matrix imaging polarimetry with artificial intelligence provides further advantages in detecting different kinds of medical conditions in an automated manner. Accordingly, the present study proposes a method based on Mueller matrix polarimetry and machine learning algorithms for discriminating between (1) four different types of mice skin tissues (normal, acanthosis, papilloma, and squamous cell carcinoma); (2) two types of mice skin tissues which show histological similarities to human equivalents (normal and squamous cell carcinoma); and (3) 7,12-dimethylbenz[a]anthracene/estrogen-induced mice skin tissues. Five machine learning classifiers, namely Random Forest, Support Vector Machine, K-Nearest Neighbor, Gradient Boosting, and Gaussian Naïve Bayes, are considered in the first and second applications, while three models (Support Vector Machine, K-Nearest Neighbor, Gradient Boosting) are considered in the third application. For each application, the features which dominate the machine learning prediction performance are determined through multivariate correlation matrix analysis, kernel density estimation, and Analysis of Variance tests. The experimental results show that the Random Forest model achieves the highest classification accuracy (93.55 %) for the first application, while the Support Vector Machine model yields the highest accuracy for both the second and third applications (97.66 % and 100 %, respectively). Overall, the proposed framework consisting of Mueller matrix imaging polarimetry and machine learning provides a strong foundation for the on-going development of screening and diagnosis methods for human skin cancer.

Dynamic Mueller matrix polarimetry using generalized measurements

Mueller matrices provide a complete description of a medium’s response to excitation by polarized light, and their characterization is important across a broad range of applications from ellipsometry in material science to polarimetry in biochemistry, medicine and astronomy. Here we introduce single-shot Mueller matrix polarimetry based on generalized measurements performed with a Poincaré beam. We determine the Mueller matrix of a homogeneous medium with unknown optical activity by detecting its optical response to a Poincaré beam, which across its profile contains all polarization states, and analyze the resulting polarization pattern in terms of four generalized measurements, which are implemented as a path-displaced Sagnac interferometer. We illustrate the working of our Mueller matrix polarimetry on the example of tilted and rotated wave plates and find excellent agreement with predictions as well as alternative Stokes measurements. After initial calibration, the alignment of the device stays stable for up to 8 hours, promising suitability for the dynamic characterization of Mueller matrices that change in time. Unlike traditional rotating waveplate polarimetry, our method allows the acquisition of a sample’s dynamic Mueller matrix. We expect that our feasibility study could be developed into a practical and versatile tool for the real-time analysis of optical activity changes, with applications in biomedical and biochemical research and industrial monitoring.

Optimizing near-infrared polariscopic imaging for the living human eye

Hardware architectures and image interpretation can be simplified by partial polarimetry. Mueller matrix (MM) polarimetry allows the investigation of partial polarimeter designs for a given scientific task. In this work, we use MM measurements to solve for a fixed polarization illumination and analyzer state that maximize polariscopic image contrast of the human eye. The eye MM image acquisition takes place over 15 seconds which motivates the development of a partial polarimeter that has snapshot operation. Within the eye, the birefringent cornea produces spatially-varying patterns of retardance exceeding half of a wave with a fast-axis varying from linear, to circular, and elliptical states in between. Our closed-form polariscopic pairs are a general solution that maximizes contrast between two non-depolarizing pure retarder MMs. For these MMs, there is a family of polariscopic pairs that maximize contrast. This range of solutions creates an opportunity to use the distance from optimal as a criteria to adjust polarimetric hardware architecture. We demonstrate our optimization approach by performing both Mueller and polariscopic imaging of an in vivo human eye at 947 nm using a dual-rotating-retarder polarimeter. Polariscopic images are simulated from Mueller measurements of 19 other human subjects to test the robustness of this optimal solution.

Complex Spatial Illumination Scheme Optimization of Backscattering Mueller Matrix Polarimetry for Tissue Imaging and Biosensing.

Polarization imaging and sensing techniques have shown great potential for biomedical and clinical applications. As a novel optical biosensing technology, Mueller matrix polarimetry can provide abundant microstructural information of tissue samples. However, polarimetric aberrations, which lead to inaccurate characterization of polarization properties, can be induced by uneven biomedical sample surfaces while measuring Mueller matrices with complex spatial illuminations. In this study, we analyze the detailed features of complex spatial illumination-induced aberrations by measuring the backscattering Mueller matrices of experimental phantom and tissue samples. We obtain the aberrations under different spatial illumination schemes in Mueller matrix imaging. Furthermore, we give the corresponding suggestions for selecting appropriate illumination schemes to extract specific polarization properties, and then provide strategies to alleviate polarimetric aberrations by adjusting the incident and detection angles in Mueller matrix imaging. The optimized scheme gives critical criteria for the spatial illumination scheme selection of non-collinear backscattering Mueller matrix measurements, which can be helpful for the further development of quantitative tissue polarimetric imaging and biosensing.

Monitoring of multiple fabrication parameters of electrospun polymer fibers using mueller matrix analysis

Electrospun polymer fiber mats feature versatile applications in tissue engineering, drug delivery, water treatment and chemical processes. The orientation of fibers within these mats is a crucial factor that significantly influences their properties and performance. However, the analysis of fiber samples using scanning electron microscopy (SEM) has limitations such as time consumption, fixed assembly, and restricted field of vision. Therefore, a fast and reliable method for qualitative measurements of fiber orientation is required. Mueller matrix polarimetry, a well-established method for measuring orientation of chemical and biological species, was employed in this case. We investigated the effect of four important parameters of the electrospinning process, namely collector speed, applied voltage, needle-to-collector distance, and solution concentration, on fiber orientation using Mueller matrix polarimetry thus extending the range of parameters analyzed. Measurements were performed using two extreme values and a central optimized value for each fabrication parameter. Changes in matrix values were observed for each fabrication parameter, and their correlation with fiber orientation was analyzed based on the Lu-Chipman decomposition. The results were compared with SEM images, which served as the ground truth, and showed overall good agreement. In the future, the analysis of electrospun polymer fibers can be done by using Mueller matrix polarimetry as alternative to current technology and fabrication parameters, including solution concentration for the first time in this context and the production can quickly be adjusted based on the outcome of the measurements.

Ultrafast polarization characterization with Mueller matrix based on optical time-stretch and spectral encoding.

High-speed optical polarization characterization is highly desirable for a wide range of applications, including remote sensing, telecommunication, and medical diagnosis. The utilization of the Mueller matrix provides a superior systematic and comprehensive approach to represent polarization attributes when matter interacts with optical beams. However, the current measurement speed of Mueller matrix is limited to only seconds or milliseconds. In this study, we present an ultrafast Mueller matrix polarimetry (MMP) technique based on optical time-stretch and spectral encoding that enables us to achieve an impressive temporal resolution of 4.83 nanoseconds for accurate Mueller matrix measurements. The unique feature of optical time-stretch technology enables continuous, ultrafast single-shot spectroscopy, resulting in a remarkable speed of up to 207 MHz for spectral encoding Mueller matrix measurement. We have employed an effective Mueller linear reconstruction algorithm based on the measured modulation matrix, accounting for all potential non-ideal effects of polarization components like retardance error and azimuth error. To ensure high precision, prior to the actual measurement, high-order dispersion induced by time-stretch requires adjustment through proper modulation matrix design. Upon such correction, both the results of static and rapid dynamic samples measurements exhibit exceptional accuracy with root-mean-square error (RMSE) approximately equal to 0.04 and 0.07 respectively. This presented ultrafast MMP provides a significant advance over preceding endeavors, enabling superior accuracy and increased speed concurrently.

Disentangling optical effects in 3D spiral-like, chiral plasmonic assemblies templated by a dark conglomerate liquid crystal.

Chiral thin films showing electronic and plasmonic circular dichroism (CD) are intensively explored for optoelectronic applications. The most studied chiral organic films are the composites exhibiting a helical geometry, which often causes entanglement of circular optical properties with unwanted linear optical effects (linearly polarized absorption or refraction). This entanglement limits tunability and often translates to a complex optical response. This paper describes chiral films based on dark conglomerate, sponge-like, liquid crystal films, which go beyond the usual helical type geometry, waiving the problem of linear contributions to chiroptical electronic and plasmonic properties. First, we show that purely organic films exhibit high electronic CD and circular birefringence, as studied in detail using Mueller matrix polarimetry. Analogous linear properties are two orders of magnitude lower, highlighting the benefits of using the bi-isotropic dark conglomerate liquid crystal for chiroptical purposes. Next, we show that the liquid crystal can act as a template to guide the assembly of chemically compatible gold nanoparticles into 3D spiral-like assemblies. The Mueller matrix polarimetry measurements confirm that these composites exhibit both electronic and plasmonic circular dichroisms, while nanoparticle presence is not compromising the beneficial optical properties of the matrix.

Mueller matrix-based characterization of cervical tissue sections: a quantitative comparison of polar and differential decomposition methods.

Quantitative optical polarimetry has received considerable recent attention owing to its potential for being an efficient diagnosis and characterizing tool with potential applications in biomedical research and various other disciplines. In this regard, it is crucial to validate various Mueller matrix (MM) decomposition methods, which are utilized to extract and quantify the intrinsic individual polarization anisotropy properties of various complex optical media. To quantitatively compare the performance of both polar and differential MM decomposition methods for probing the structural and morphological changes in complex optical media through analyzing their intrinsic individual polarization parameters, which are extracted using the respective decomposition algorithms. We also intend to utilize the decomposition-derived anisotropy parameters to distinguish among the cervical tissues with different grades of cervical intraepithelial neoplasia (CIN) and to characterize the healing efficiency of an organic crystal. Polarization MM of the cervical tissues with different grades of CIN and the different stages of the self-healing crystal are recorded with a home-built MM imaging setup in the transmission detection geometry with a spatial resolution of . The measured MMs are then processed with both the polar and differential MM decomposition methods to extract the individual polarization parameters of the respective samples. The derived polarization parameters are further analyzed to validate and compare the performance of both the MM decomposition methods for probing and characterizing the structural changes in the respective investigated optical media through their decomposition-derived intrinsic individual polarization properties. Pronounced differences in the decomposed-derived polarization anisotropy parameters are observed for cervical tissue sections with different grades of CIN. While a significant increase in the depolarization parameter is obtained with the increment of CIN stages for both the polar [ for CIN grade one (CIN-I) and for CIN grade two (CIN-II))] and differential ( for CIN-I and for CIN-II) decomposition methods, a trend reversal is seen for the linear diattenuation parameter , indicating the structural distortion in the cervical morphology due to the CIN disease. More importantly, with the differential decomposition algorithm, the magnitude of the derived parameter decreases from 0.26 to 0.19 with the progression of CIN, which was not being probed by the polar decomposition method. Our results demonstrate that the differential decomposition of MM holds certain advantages over the polar decomposition method to characterize and probe the structural changes in the cervical tissues with different grades of CIN. Although the quantified individual polarization parameters obtained through both the MM decomposition methods can be used as useful metrics to characterize various optical media, in case of complex turbid media such as biological tissues, incorporation of the differential decomposition technique may yield more efficient information. Also, the study highlights the utilization of MM polarimetry with an appropriate decomposition technique as an efficient diagnostic and characterizing tool in the realm of biomedical clinical research, and various other disciplines.

Discrepancy of coordinate system selection in backscattering Mueller matrix polarimetry: exploring photon coordinate system transformation invariants.

In biomedical studies, Mueller matrix polarimetry is gaining increasing attention because it can comprehensively characterize polarization-related vectorial properties of the sample, which are crucial for microstructural identification and evaluation. For backscattering Mueller matrix polarimetry, there are two photon coordinate selection conventions, which can affect the following Mueller matrix parameters calculation and information acquisition quantitatively. In this study, we systematically analyze the influence of photon coordinate system selection on the backscattering Mueller matrix polarimetry. We compare the Mueller matrix elements in the right-handed-nonunitary and non-right-handed-unitary coordinate systems, and specifically deduce the changes of Mueller matrix polar decomposition, Mueller matrix Cloude decomposition and Mueller matrix transformation parameters widely used in backscattering Mueller matrix imaging as the photon coordinate system varied. Based on the theoretical analysis and phantom experiments, we provide a group of photon coordinate system transformation invariants for backscattering Mueller matrix polarimetry. The findings presented in this study give a crucial criterion of parameters selection for backscattering Mueller matrix imaging under different photon coordinate systems.

Decomposition Mueller matrix polarimetry for enhanced miRNA detection with antimonene-based surface plasmon resonance sensor and DNA-linked gold nanoparticle signal amplification

A decomposition Mueller matrix method is proposed for detection of miRNA and enhanced by using a surface plasmon resonance (SPR). In the proposed approach, a Mueller matrix decomposition method is employed to extract the linear birefringence (LB) and circular dichroism (CD) properties of the miRNA sample. The accuracy of the LB and CD measurements is enhanced through the use of a high-resolution antimonene-based SPR prism coupler with DNA-linked gold nanoparticles (AuNPs). The feasibility of the proposed method is demonstrated by measuring the LB orientation angle (α) and CD property (R) of two miRNA aqueous solutions (hsa-miR-125-5p and hsa-miR-21-5p) over the concentration range of 0∼1000 fM in both cases. The results show that, for both samples, α and R vary linearly with the change in the miRNA concentration. Furthermore, the values of α and R obtained for the two samples are quantifiably different, and hence the selectivity of the proposed SPR sensor is confirmed. Overall, the results highlight the potential of the proposed sensor as a valuable tool for miRNA detection with prospective applications in cancer diagnosis.

Unrestricted Chiral Patterning by Laser Writing in Liquid Crystalline and Plasmonic Nanocomposite Thin Films.

Obtaining hierarchical structures with arbitrarily controlled chirality remains a challenge. Here, thin films featuring chiroptically bipolar patterns are produced by a device utilizing microscale photothermal re-melting of materials exhibiting chirality synchronization. This device operates autonomously, guided by an algorithm that facilitates the homochiral growth of supramolecular organic helices through controlling their re-melting. The chirality synchronization phenomena of constitutionally achiral molecules grants availability of both handednesses of the helices, enabling unrestricted chiral writing in the film. The collective chiroptical response of assembled molecules is utilised to guide the patterning process, creating a foundation for optically secured information. The established methodology enables achieving dissymmetry factor values for circular dichroism (CD) a magnitude higher than previously reported, as confirmed with state-of-the-art, synchrotron-based Mueller matrix polarimetry (MMP). Moreover, the developed method is extended to nanocomposites comprising gold nanoparticles, providing the opportunity to tune the CD toward the plasmonic region. This strategic application of photothermal processing, specifically laser-directed melting, uncovers the potential to broaden the selection of nanostructured materials with precisely designed functionalities for photonic applications.

Wide-field Mueller matrix polarimetry for spectral characterization of basic biological tissues: Muscle, fat, connective tissue, and skin.

This study investigates the polarimetric properties of skin, skeletal muscle, connective tissue, and fat using Mueller matrix imaging. It aims to compare the polarimetric characteristics of these tissues and explore how they evolve with wavelength. Additionally, the temporal evolution of certain tissues during meat aging is studied, providing insights into the dynamic behavior of polarimetric properties over time. The research employs back-scattering configuration and the differential decomposition analysis method of Mueller matrix images. Both in-vivo and ex-vivo experiments were conducted using a consistent instrument setup to ensure reliable analysis. The results reveal wavelength-dependent variations in tissue properties, including an increase in depolarization with wavelength. Significant differences in the polarimetric characteristics of meat tissues, particularly for skeletal muscle, are observed. Over a 24-h period, intensity, diattenuation, and retardation experience alterations, being the decreased retardation in skeletal muscle and the increased retardation in fat the most notable ones.

Analyzing the influence of oblique incidence on quantitative backscattering tissue polarimetry: a pilot ex vivo study.

Among the available polarimetric techniques, backscattering Mueller matrix (MM) polarimetry provides a promising non-contact and quantitative tool for in vivo tissue detection and clinical diagnosis. To eliminate the surface reflection from the sample cost-effectively, the non-collinear backscattering MM imaging setup always has an oblique incidence. Meanwhile, for practical organ cavities imaged using polarimetric gastrointestinal endoscopy, the uneven tissue surfaces can induce various relative oblique incidences inevitably, which can affect the polarimetry in a complicated manner and needs to be considered for detailed study. The purpose of this study is to systematically analyze the influence of oblique incidence on backscattering tissue polarimetry. We measured the MMs of experimental phantom and ex vivo tissues with different incident angles and adopted a Monte Carlo simulation program based on cylindrical scattering model for further verification and analysis. Meanwhile, the results were quantitatively evaluated using the Fourier transform, basic statistics, and frequency distribution histograms. Oblique incidence can induce different changes on non-periodic, two-periodic, and four-periodic MM elements, leading to false-positive and false-negative polarization information for tissue polarimetry. Moreover, a prominent oblique incidence can bring more dramatic signal variations, such as phase retardance and element transposition. The findings presented in this study give some crucial criterions of appropriate incident angle selections for in vivo polarimetric endoscopy and other applications and can also be valuable references for studying how to minimize the influence further.

Mueller-matrix imaging polarimetry elevated by wavelet decomposition and polarization-singular processing for analysis of specific cancerous tissue pathology.

Mueller-matrix polarimetry is a powerful method allowing for the visualization of malformations in biological tissues and quantitative evaluation of alterations associated with the progression of various diseases. This approach, in fact, is limited in observation of spatial localization and scale-selective changes in the poly-crystalline compound of tissue samples. We aimed to improve the Mueller-matrix polarimetry approach by implementing the wavelet decomposition accompanied with the polarization-singular processing for express differential diagnosis of local changes in the poly-crystalline structure of tissue samples with various pathology. Mueller-matrix maps obtained experimentally in transmitted mode are processed utilizing a combination of a topological singular polarization approach and scale-selective wavelet analysis for quantitative assessment of the adenoma and carcinoma histological sections of the prostate tissues. A relationship between the characteristic values of the Mueller-matrix elements and singular states of linear and circular polarization is established within the framework of the phase anisotropy phenomenological model in terms of linear birefringence. A robust method for expedited (up to ) polarimetric-based differential diagnosis of local variations in the poly-crystalline structure of tissue samples containing various pathology abnormalities is introduced. The benign and malignant states of the prostate tissue are identified and assessed quantitatively with a superior accuracy provided by the developed Mueller-matrix polarimetry approach.

Combination of muller matrix polarimetry and z-scan techniques for nonlinear refractive index measurement

Polarization state of light affects the results of nonlinear refractive index measurement. In this work by integrating Mueller matrix polarimetry with z-scan technique, reciprocal effects of optical nonlinearity and polarization is studied. By using classical Muller matrix polarimetry, polarization states generate before the sample in z-scan system and polarization state analyze after sample and before close aperture detector. By using a CW laser at 655 nm wavelength, thermal nonlinear refractive index of an Azo dye, Janus Green B, was measured. The results are very sensitive to polarization states. The measured Muller matrix in each position of sample result the nonlinear dependence of related Deattenuation, Retardance and Depolarization parameters.

Effects of graphene layer addition on sensitivity of surface plasmon resonance sensor for immunoglobulin M detection

A novel technique is proposed for detecting immunoglobulin M (IgM) using differential Mueller matrix polarimetry and a surface plasmon resonance (SPR) sensor enhanced through the addition of multiple (1–10) thin layers of graphene on the sensing surface. Simulations are first performed to optimize the structure of the SPR device. The feasibility of the proposed sensor is then demonstrated by measuring the principal fast axis angle (α) of linear birefringence (LB) of human IgM serum aqueous solution samples with known concentrations in the range of 0–250 ng/ml. The results shows that α increases linearly over the considered concentration range. However, α reduces with an increasing number of graphene layers. The finest resolution of 7.8 ng/ml is obtained from the sensor incorporating three graphene layers.

Microscopic single-pixel polarimetry for biological tissue

Single-pixel imaging (SPI) is a computational imaging modality that reconstructs images from information collected with a single-pixel detector. Due to the relatively large bandwidth and cheap price of single-pixel detectors over pixel-array detectors, SPI has been demonstrated with great success in many imaging scenarios. In this work, we further extended SPI to microscopic Mueller-matrix polarimetry, which is capable of providing polarization-sensitive properties of biological tissue with a millimeter-size field of view and micrometer-size resolution. As a proof of concept, we applied polarimetry on normal and cancerous esophagus tissues from patients and reconstructed their Mueller matrices. Effects of depolarization, retardation, and diattenuation were also examined by decomposing Mueller matrices. We envision that the developed computational technique can bring new possibilities for both SPI and Mueller-matrix polarimetry.