Mueller Matrix Imaging Polarimeter Research Articles

Fast and high-accuracy collinear reflection Mueller imaging polarimeter implemented with the compound calibration method

The collinear reflection Mueller matrix imaging polarimeter is suitable for characterizing thick samples with high-scattering depolarization such as biological tissues or in-situ living organs. Achieving fast detection and high measurement accuracy is vital to prevent artifacts and accurately assess polarization characteristics in these applications. This paper demonstrates a fast collinear reflection imaging polarimeter based on liquid crystal variable retarders (LCVRs-CRMMIP). We propose a novel compound calibration method (CCM), to the best of our knowledge, which enhances measurement accuracy through light intensity correction and an improved equivalent calibration sample model. This method surpasses the double-pass eigenvalue calibration method (dp-ECM), enhancing accuracy by over 23 times. Performance evaluations with standard samples, including mirrors, linear polarizers, and wave plates, reveal that the LCVRs-CRMMIP achieves rapid measurements (about 3 s) and high accuracy with an error of less than 0.0017.

Mueller matrix imaging polarimeter with polarization camera self-calibration applied to structured light components

This work presents a complete Mueller matrix imaging polarimeter that uses three liquid-crystal retarders and a pixelated polarization camera. The polarimeter is characterized and optimized with a standard correction procedure here adapted to be performed fully in-situ, without any additional element, based on considering the polarization camera as the reference. The accuracy limit caused by the extinction ratio in the camera micro-polarizers is analyzed. Finally, the imaging polarimeter is tested experimentally by analyzing well-known samples for structured light applications such as patterned retarders, a patterned polarizer, and a liquid-crystal depolarizer. The work is presented in a tutorial style useful to reproduce the procedure by non-experts in polarimetry.

Scene-adaptive spatially channeled imaging Mueller polarimeter.

A spatially adaptive Mueller matrix imaging polarimeter is described, simulated, and demonstrated with preliminary experiments. The system uses a spatial light modulator (SLM) in the polarization state generator (PSG) to create spatial carriers that controlled by the pattern written to the SLM. The polarization state analyzer (PSA) is a commercial division of focal plane imaging polarimeter. The PSG/PSA pair form a 9-channeled partial Mueller matrix polarimeter that measures a 3 × 3 sub-matrix of the Mueller matrix. We demonstrate that adapting the PSG modulation to the spatial frequency structure of the scene can reduce channel crosstalk and improve reconstruction accuracy. Initial experiments are performed that demonstrate the SLM's ability to produce sufficient modulation diversity to create the desired channel structure. Though there are several experimental challenges to obtain accurate Mueller matrix imagery, we demonstrate a system that adapts to the particular scene spatial frequency structure.

Distinguishing Malignant Melanoma and Benign Nevus of Human Skin by Retardance Using Mueller Matrix Imaging Polarimeter

Malignant melanoma is considered the most serious type of skin cancer. In clinical practice, the conventional technique based on subjective visual examination has a high rate of misdiagnosis for malignant melanoma and benign nevus. Polarization imaging techniques have great potential in clinical diagnosis due to the advantages of improving sensitivity to functional structures, such as microfiber. In this paper, a set of human skin tissue sections, including 853 normal, 851 benign nevus, and 874 malignant melanoma, were analyzed and differentiated using a homemade high-fidelity Mueller matrix imaging polarimeter. The quantitative result using support vector machine algorithms confirmed that, while scalar retardance yields lower accuracy rates, vectorial retardance results in greater accuracy for both the training and testing sets. In particular, the cross-validation accuracy for the training set increased from 88.33% to 98.60%, and the prediction accuracy for the testing set increased from 87.92% to 96.19%. This tackles the limitation of the examination based on clinical experience and suggests that vectorial retardance can provide more accurate diagnostic evidence than scalar retardance. Unfortunately, it is inconvenient and time-consuming to read and analyze each component of the vectorial retardance simultaneously in the qualitative assessment. To address this clinical challenge, a color-encoded vectorial retardance imaging method was implemented. This method can provide superior tissue-specific contrast and more fiber details than scalar retardance. The anisotropic microfiber variation among different skin lesions, including the orientation and distribution, can be clearly highlighted. We believe that this work will not only enable early and rapid diagnosis of skin cancer but also provide a good observation and analysis of the state of cancer progression.

Mueller matrix imaging polarimeter at the wavelength of 265 nm.

Mueller matrix imaging polarimeters (MMIPs) have been developed in the wavelength region of >400n m with great potential in many fields yet leaving a void of instrumentation and application in the ultraviolet (UV) region. For the first time to our knowledge, an UV-MMIP is developed for high resolution, sensitivity, and accuracy at the wavelength of 265nm. A modified polarization state analyzer is designed and applied to suppress stray light for nice polarization images, and the errors of the measured Mueller matrices are calibrated to lower than 0.007 in pixel level. The finer performance of the UV-MMIP is demonstrated by the measurements of unstained cervical intraepithelial neoplasia (CIN) specimens. The contrasts of depolarization images obtained by the UV-MMIP are dramatically improved over those obtained by our previous VIS-MMIP at the wavelength of 650nm. A distinct evolution of depolarization in normal cervical epithelium tissue, CIN-I, CIN-II, and CIN-III specimens can be observed by the UV-MMIP with mean depolarization promotion by up to 20 times. This evolution could provide important evidence for CIN staging but can hardly be distinguished by the VIS-MMIP. The results prove that the UV-MMIP could be an effective tool in polarimetric applications with higher sensitivity.

Complete Mueller matrix imaging polarimeter for evaluating optical components for structured light

We present a complete Mueller matrix (MM) imaging polarimeter based on liquid-crystal retarders and a pixelated polarization camera. The polarimeter instrument is first calibrated and optimized, and then applied for the precise characterization of optical components used for the generation of structured light, like patterned retarders and patterned polarizers.

Holistic and efficient calibration method for Mueller matrix imaging polarimeter with a high numerical aperture.

High-numerical aperture (N A>0.6) Mueller matrix imaging polarimeter (MMIP) (high-NA MMIP) is urgently needed for higher resolution. Usually, the working distance of high-NA MMIP is too short to perform in situ calibration by a usual reference sample, such as polarizer and retarder plates. The polarization effects of the substrate that attach the sample are never calibrated. So, the resolution and accuracy of the MMIP is hard to further promote. In this paper, a holistic and efficient calibration method is innovated for high-NA MMIP. Two film polarizers and a film retarder as well as a blank substrate are first adopted as the reference samples in calibration. Different from the conventional eigenvalue calibration method (ECM), the holistic calibration theory and process are established. All polarimetric errors arising from the devices, subsystems, and the substrate can be calibrated in one process. The normalized measurement error is less than 0.0024 for NA 0.95 MMIP, which is an order of magnitude lower than those of NA 0.1 and 0.2 MMIPs in publications. The excellent performance of calibrated high-NA MMIP is demonstrated by tissue polarimetry with higher resolution, accuracy, and more appropriate dynamic range.

Mueller matrix imaging with a polarization camera: application to microscopy.

In this work, we describe the design and implementation of a Mueller matrix imaging polarimeter that uses a polarization camera as a detector. This camera simultaneously measures the first three Stokes components, allowing for the top three rows of the Mueller matrix to be determined after only N = 4 measurements using a single rotating compensator, which is sufficient to fully characterize nondepolarizing samples. This setup provides the polarimetric analysis with micrometric resolution in about 3 seconds and can also perform live birefringence imaging at the camera frame rate by fixing the compensator at a static 45° angle. To further improve the conditioning of the setup, we also give the first experimental demonstration of an optimal elliptical retarder design.

Quantifying optical anisotropy in soft tissue membranes using Mueller matrix imaging.

.Significance: A non-destructive technique for accurately characterizing the spatial distribution of optical properties of soft tissue membranes may give improved outcomes in many tissue engineering applications.Aim: This study aimed to develop a non-destructive macroscopic imaging technique that is sensitive to optical anisotropy, typical of fibrous components in soft tissue membranes, and can address some of the difficulties caused by the complex turbid nature of these tissues.Approach: A near-infrared Mueller matrix imaging polarimeter employing logarithm decomposition was developed and used to conduct transmission measurements of all the polarization properties across the full thickness of bovine pericardium tissue.Results: The full Mueller matrix was measured across a sample of calf bovine pericardium and revealed significant retardance (linear and circular) and depolarization in this tissue. Regions with a uniform axis of optical anisotropy were identified. Mueller matrix imaging demonstrated that the exhibited circular retardance was sufficient to lead to possible misinterpretation of apparent fiber orientation when using conventional polarization imaging techniques for such tissues.Conclusions: Mueller matrix imaging can identify regional distributions of optical anisotropy in calf bovine pericardium. This new capability is a promising development in non-destructive imaging for tissue selection.

Spatially Addressable Polarimetric Calibration of Reflective-Type Spatial Light Modulator Using Mueller–Stokes Polarimetry

Mueller–Stokes polarimetry is emerging as a prominent noninvasive imaging technique to study the structural characteristics of an anisotropic medium. Spatial light modulator (SLM) is a programmable liquid crystal device (LCD), which is used to modulate the amplitude, phase, and polarization of light. The compact design and cumbrous manufacturing process of SLM requires its polarimetric calibration prior to its utilization for various applications. In this study, we experimentally demonstrate Mueller–Stokes imaging of a reflective-type SLM (Holoeye, LCR-720) to calibrate its polarization modulation characteristics with respect to its dynamic gray value range (0–255) at different spatial locations of SLM screen. Mueller matrices at 18 different gray values of SLM at an interval of 15, that is, at gray values 0, 15, 30, up to 255 have been experimentally measured using an improvised Mueller matrix imaging polarimeter (MMIP). Crucial polarimetric characteristics, that is, diattenuation, polarizance, state of polarization (SOP), depolarization, and retardance have been estimated with respect to the gray value range of SLM. Significant polarization modulation characteristics [diattenuation (0.08–0.3), polarizance (0.02–0.2), and retardance (0 to π)] have been determined for the SLM. These results indicate that the SLM exhibits spatially variable depolarizing nature and hence it is not perfectly homogeneous in structure. Therefore, it is expected that the outcomes of this study would be helpful for exploring the applicability of Mueller–Stokes polarimetry in advancement of LC technology.

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AbstractThe possibilities of using Mueller matrix (MM) imaging polarimetry to assess meat quality have not yet been sufficiently explored. In the current study, the fresh porcine muscles are imaged at room emperature with a wide‐field MM imaging polarimeter over 26 hours to visualize dynamics of tissue optical properties through applying Lu‐Chipman decomposition. The MM images, frequency distribution histograms and statistical analysis of the MM elements show prominent changes over time.Further details can be found in the article by M. Peyvasteh, A. Popov, A. Bykov, A. Pierangelo, T. Novikova, I. Meglinski (e202000376) image

Evolution of raw meat polarization-based properties by means of Mueller matrix imaging.

The possibilities of using Mueller matrix (MM) imaging polarimetry to assess meat quality have not yet been sufficiently explored. In the current study, the fresh porcine muscles are imaged at room temperature with a wide-field MM imaging polarimeter over 26 hours to visualize dynamics of tissue optical properties through applying Lu-Chipman decomposition. The frequency distribution histograms (FDHs) and statistical analysis of the MM elements show prominent changes over time. The wavelength spectra of both total depolarization and scalar retardance have dips at 550 nm whereas their values continuously increase with time; the former is referred to the increase of number of scattering events and decrease of myoglobin absorption in the red part of visible spectra related to meat color and freshness, while the latter is associated with the increase in birefringence and meat tenderness. The obtained results are promising to develop a novel fast noncontact optical technique for monitoring of meat quality.

Rational Analysis of Self-Alignment Force of Reactive Additive Monomer with Multiple Methods

Analysis self-alignment force (SAF) of reactive self-assambly additive monomer is highly valuable in self-alignment vertical alignment mode(SAVA), because this force directly influences performance of optoelectronics device. In this work, SAF has been studied by multiple methods, such as atomic force microscopy, mueller matrix imaging polarimeter. Reactive additive monomer and LC molecular were immobilized on the surface of an AFM probe and ITO, respectively. Due to the complexity of the additive monomer-hydroxy, additive monomer-LC moluclar interaction, parallel experiments were designed to discriminate specific interactions. The difference of pretilt angle between TFT side and CF side also reveals the difference of SAF at various structure cell.The additive with strong SAF showed well alignment state after forming into optoelectronice device.

P‐157: Rational Analysis of Self‐Alignment Force of Reactive Additive Monomer with Multiple Methods

Analysis self‐alignment force (SAF) of reactive self‐assembly additive monomer is highly valuable in self‐alignment vertical alignment mode(SAVA), because this force directly influence performance of optoelectronics device. In this work, SAF has been studied by multiple methods, such as atomic force microscopy, mueller matrix imaging polarimeter. Reactive additive monomer and LC molecular were immobilized on the surface of an AFM probe and ITO, respectively. Due to the complexity of the additive monomer‐hydroxy, additive monomer‐LC moluclar interaction, parallel experiments were designed to discriminate specific interactions. The difference of pretilt angle between TFT side and CF side also reveals the difference of SAF at various structure cell. The additive with strong SAF showed well alignment state after forming into optoelectronic device.

Comparing Classification Performance of Mueller Matrix Parameters for Diffuse Materials

This work compares the material classification performance of Mueller matrix polarization imaging to RGB imaging. White painted wood and white fabric samples are selected to create a classification task that is challenging for RGB imaging. A Mueller Matrix Imaging Polarimeter with a 30° full field of view is used to capture the Mueller Matrix images at nominal red, green, and blue wavelengths across multiple specular scatter angles. A Bayesian ideal observer model is used to evaluate classification performance. Performance is quantified by the Area under (AUC) the Receiver Operating Characteristic (ROC) curve. An AUC = 1 is perfect detection and AUC = 0.5 is the performance of guessing. The ensemble average AUC does not exceed 0.70 for RGB irradiance data. The ensemble average AUC for all 16 individual Mueller elements is greater than 0.95. Various combinations of Mueller matrix elements are also tested. Elements related to diattenuation and polarizance are nearly perfect classifiers for large scatter angles but the AUC minimum is 0.60 at 20°. Depolarization index is the highest performing parameter out of all tested polarization parameters for scatter angles ≥70° where AUC ≥0.98.

Jones pupil metrology of lithographic projection lens and its optimal configuration in the presence of error sources.

Mueller matrix imaging polarimeter (MMIP) can be used to measure the polarization aberration (PA) of a lithographic projector in the form of the Mueller pupil, while the Jones pupil is required for lithographic imaging simulations, projection lens design and PA evaluation. In this paper, a Jones pupil measurement method of lithographic projection lens is proposed. The measurement device of the method is the same as an MMIP, but a new polarimetric measurement equation is derived to solve the Jones pupil directly from the Kronecker product of the Jones matrix and the measured intensities. Two new polarimeter configurations with the minimum condition number are designed to further improve the accuracy in the presence of error sources. The performance of the method is evaluated by measurement errors of a typical Jones pupil in the presence of error sources. Comparisons between the proposed method and the conventional method, in which the Jones pupil is converted from the Mueller pupil measured by MMIP, are given. The results validate that the measurement accuracy of the Jones pupil is significantly improved without increasing the complexity of existing measurement systems.

穆勒矩阵成像椭偏仪误差源的简化分析方法

穆勒矩阵成像椭偏仪误差源的简化分析方法

Accuracy enhancement of dual rotating mueller matrix imaging polarimeter by diattenuation and retardance error calibration approach

We present a new calibration method to minimize the errors due to non-ideal retarders of a dual rotating Mueller matrix polarimeter. To increase the accuracy of the dual rotating retarder polarimeter, it is necessary to compensate the errors caused by the inaccuracy of retarders. Although calibration method for retardance already exists, limitations on the accuracy have been obtained by considering only the retardance errors. In the proposed model we added the calibration of diattenuation error of the retarder along with retardance error on the standard model. An enhancement in the accuracy of the system is obtained. The proposed model is described with equations and supporting experimental results are presented.

Mueller 矩阵成像偏振仪的误差标定和补偿研究

Mueller 矩阵成像偏振仪的误差标定和补偿研究

Patterned cholesteric liquid crystal polymer film

Herein, the ability to create arbitrarily patterned circular polarized optical devices is demonstrated by using cholesteric liquid crystal polymer. Photoalignment with polarized ultraviolet light is utilized to create aligned cholesteric liquid crystal films. Two different methods, thermal annealing and solvent rinse, are utilized for patterning cholesteric liquid crystal films over large areas. The patterned cholesteric liquid crystal films are measured using a Mueller matrix imaging polarimeter, and the polarization properties, including depolarization index, circular diattenuation (CD), and circular retardance are derived. Patterned nonlinearly polarized optical devices can be fabricated with feature sizes as small as 20μm with a CD of 0.812±0.015. Circular polarizing filters based on polymer cholesteric liquid crystal films have applications in three-dimensional displays, medical imaging, polarimetry, and interferometry.