- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Metrology of Nanostructures by Tomographic Mueller-Matrix Scatterometry
摘要： The development of necessary instrumentation and metrology at the nanoscale, especially fast, low-cost, and nondestructive metrology techniques, is of great significance for the realization of reliable and repeatable nanomanufacturing. In this work, we present the application of a homemade novel optical scatterometer called the tomographic Mueller-matrix scatterometer (TMS), for the measurement of photoresist gratings. The TMS adopts a dual rotating-compensator configuration and illuminates the nanostructure sequentially under test conditions by a plane wave, with varying illumination directions and records. For each illumination direction, the polarized scattered field along various directions of observation can be seen in the form of scattering Mueller matrices. That more scattering information is collected by TMS than conventional optical scatterometry ensures that it achieves better measurement sensitivity and accuracy. We also show the capability of TMS for determining both grating pitch and other structural parameters, which is incapable by current zeroth-order methods such as reflectometry- or ellipsometry-based scatterometry.
关键词： inverse scattering,ellipsometry,pitch measurement,diffraction grating,scatterometry,Mueller matrix
更新于2025-09-23 15:23:52
-
3D Mueller-Matrix Diffusive Tomography of Polycrystalline Blood Films for Cancer Diagnosis
摘要： The decomposition of the Mueller matrix of blood films has been carried out using differential matrices with polarized and depolarized parts. The use of a coherent reference wave is applied and the algorithm of digital holographic reconstruction of the field of complex amplitudes is used. On this basis, the 3D Mueller-matrix diffuse tomography method—the reconstruction of distributions of fluctuations of linear and circular birefringence of depolarizing polycrystalline films of human blood is analytically justified and experimentally tested. The dynamics of the change in the magnitude of the statistical moments of the first-fourth order, which characterize layer-by-layer distributions of fluctuations in the phase anisotropy of the blood film, is examined and analyzed. The most sensitive parameters for prostate cancer are the statistical moments of the third and fourth orders, which characterize the asymmetry and kurtosis of fluctuations in the linear and circular birefringence of blood films. The excellent accuracy of differentiation obtained polycrystalline films of blood from healthy donors and patients with cancer patients was achieved.
关键词： polarimetry,Mueller-matrix,blood,cancer diagnostics,polarization
更新于2025-09-23 15:23:52
-
Linear Birefringent Films of Cellulose Nanocrystals Produced by Dip-Coating
摘要： Transparent ?lms of cellulose nanocrystals (CNC) are prepared by dip-coating on glass substrates from aqueous suspensions of hydrolyzed ?lter paper. Dragging forces acting during ?lms’ deposition promote a preferential alignment of the rod-shaped CNC. Films that are 2.8 and 6.0 μm in thickness show retardance effects, as evidenced by placing them between a linearly polarized light source and a linear polarizer sheet in the extinction con?guration. Transmission Mueller matrix spectroscopic ellipsometry measurements at normal incidence as a function of sample rotation were used to characterize polarization properties. A differential decomposition of the Mueller matrix reveals linear birefringence as the unique polarization parameter. These results show a promising way for obtaining CNC birefringent ?lms by a simple and controllable method.
关键词： Mueller matrix,birefringence,nanocrystalline cellulose,nanostructured ?lms
更新于2025-09-23 15:22:29
-
Monitoring subwavelength grating structures for vertical-cavity surface-emitting laser applications by spectroscopic ellipsometry
摘要： GaAs based vertical cavity surface emitting lasers (VCSELs) have one of the fastest growing markets due to their numerous applications in imaging technology, optical sensors, and interconnects. Stable, single-mode operation of these laser diodes is often achieved by forming subwavelength structures on the surface of the GaAs semiconductor. Quick and preferably noncontact inspection of the formed nanostructures is desired during the fabrication process. Nanostructure characterization by spectral ellipsometry-based metrologies has become an indispensable tool in the semiconductor industry. An advanced method of ellipsometry is the application of Mueller-matrix ellipsometry, which enables the characterization of structure details difficult to measure or not reachable by using standard ellipsometry measurements. In this paper, the authors present the results of nanostructure characterization by model-based dimension metrology using spectral ellipsometry and Mueller-matrix spectral ellipsometry of substrates during the process of VCSEL fabrication.
关键词： Mueller-matrix ellipsometry,VCSELs,spectroscopic ellipsometry,nanostructure characterization,GaAs
更新于2025-09-11 14:15:04
-
Implementation of a complete Mueller matrix polarimeter using dual photoelastic modulators and rotating wave plates
摘要： We propose a complete Mueller matrix polarimeter using dual photoelastic modulators and rotating half wave plates. The complete Mueller matrix of a sample is obtained by combining four partial Mueller matrices (nine elements each), by rotating the half wave plates in four different orientations. By considering the effect of retardance errors of the wave plates, a more general calibration method is developed. We demonstrate the accuracy of the system by measuring a Babinet–Soleil compensator and the scattering coefficient of an intralipid sample, whereas the depolarization characteristics is shown for different column density of intralipid. Simultaneous determination of optical rotation and depolarization is verified by conducting studies on glucose concentrations ranging from 0 to 400 mg/dl mixed with 2% v/V intralipid.
关键词： Glucose measurement,Mueller matrix,Scattering particles,Photoelastic modulator,Polarimetry
更新于2025-09-10 09:29:36
-
[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Mueller Matrix Polarimetric Imaging of Prostate Tissue
摘要： Polarimetric imaging technique is a beneficial and non-destructive tool for probing the structural properties of different tissues. The obtained optical signature matrix will help clinicians to evaluate the condition of tissues. As the polarimetric properties of tissues are dependent to the structure and cellular skeleton, time lapsing may introduce variation in the polarization properties. Based on this, in the current study we have investigated the polarization properties of human prostate tissue over time. In this regard we have used polarization imaging technique based on Mueller matrix imaging and polar decomposition of Mueller matrix for extraction of polarization indicators. The tests have been performed for sample tissues immediately after surgery, and at intermittent intervals. The polarization properties have been re-measured, to follow the changes in the polarization properties of tissue over the time. The results of our study indicate that the diattenuation increases and depolarization decreases over time which can be associated with the structural properties of tissue accordingly.
关键词： Biomedical Imaging,Mueller matrix imaging,Polarization imaging,Prostate Tissue
更新于2025-09-10 09:29:36
-
[Springer Series in Optical Sciences] Fano Resonances in Optics and Microwaves Volume 219 (Physics and Applications) || Mueller Matrix Approach for Engineering Asymmetric Fano-resonance Line Shape in Anisotropic Optical System
摘要： The Fano resonances observed in diverse micro and nano optical systems have received particular attention due to their numerous potential applications like sensing, switching, lasing, ?lters and robust color display, nonlinear and slow-light devices, invisibility cloaking, and so forth. For most of these applications, it is highly desirable that the asymmetric spectral line shape of Fano resonance can be controlled or modulated by some experimentally accessible parameters. In this chapter, we discuss a new concept based on polarization Mueller matrix analysis for tuning the Fano interference effect and the resulting asymmetric spectral line shape in anisotropic optical system. The approach is founded on a generalized model of anisotropic Fano resonance and exploits the differential polarization response (anisotropy) of the two interfering modes to achieve unprecedented control over Fano resonance. Illustrative results on the use of the model for tuning Fano resonance in coupled plasmonic systems are presented. In this context, the fundamentals of polarized light, the mathematical framework of Stokes-Mueller formalism and the basic polarimetry parameters encoded in Mueller matrix are discussed. The speci?cs of a novel dark ?eld Mueller matrix spectroscopy system and its use for studying the polarization response of Fano resonance in plasmonic systems is illustrated with selected examples. The chapter concludes with an outlook on the prospects of the polarization-optimized anisotropic Fano resonant systems for applications involving control and manipulation of electromagnetic waves at the nano scale.
关键词： plasmonic systems,anisotropic optical system,Fano resonance,Mueller matrix,polarization control
更新于2025-09-09 09:28:46
-
Ellipsometry - Principles and Techniques for Materials Characterization || Photoelastic Modulated Imaging Ellipsometry
摘要： Photoelastic modulator (PEM)-based ellipsometry employed either lock-in amplifiers or the Fourier analysis technique to obtain the ellipsometric parameters almost in real-time that makes the system with a feature of fast measurement speed, higher stability, and sensitivity at small retardations. Since the PEM modulation frequency is too high to compare it with the exposure time of the camera, photoelastic modulator–based approach is not applicable for a two-dimensional ellipsometric measurement. Here, we represent a novel technique that coordinates with the light pulses and PEM modulation that can freeze the time-varied signals. Thus, two-dimensional ellipsometric parameters can be obtained within few seconds. In addition to ellipsometric measurement, this approach also can be extended to other imaging polarimetry measurements, such as Stokes parameters and Mueller matrix. Moreover, since the chromatic dispersion of birefringence was also a significant issue in the polarization modulation systems, we proposed an equivalent phase retardation technique to deal with this issue. This technique was confirmed by a dual wavelength measurement result without changing the optical configuration of the system. The concept and the theory of this system were indicated in the preceding section, and the passage below described some calibration issues for the photoelastic modulator. Some measurement results were revealed in the final part of this chapter.
关键词： imaging polarimetry,photoelastic modulator,Stokes parameter,dual wavelength,Mueller matrix,ellipsometric parameters
更新于2025-09-09 09:28:46
-
Glucose sensing in the presence of scattering by analyzing a partial Mueller matrix
摘要： We propose a method to analyze a partial Mueller matrix to retrieve the optical rotation and depolarization properties simultaneously for measuring glucose concentration in the presence of scattering. A Mueller matrix polarimeter using dual photoelastic modulators and rotating half wave plates that can retrieve four partial Mueller matrices (nine elements each) for a particular orientation of half wave plates has been applied for this purpose. We verify the proposed technique by measuring di?erent glucose concentrations from the normal to diabetic range in the absence and presence of scattering. A measurement precision of 0.004° in optical rotation and 0.0004 in depolarization is achieved, so that the sensitivity of detecting glucose concentration is obtained as low as 20 mg/dl for a 40 mm path length cuvette, even in the presence of scattering medium.
关键词： Mueller matrix,Glucose sensing,Polarimetry,Scattering
更新于2025-09-04 15:30:14
-
Method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique
摘要： The Mueller matrix is an important parameter in the field of polarization optics, and how to measure it efficiently and accurately becomes considerably significant for its practical applications. In this paper, for the first time to our knowledge, we propose a new method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique. Different from the traditional method where, for obtaining the 16 elements of the Mueller matrix, a 16-times-measurement must be conducted by jointly changing the states of polarization (SOPs) of the input and output lights, while in our method it is enough by just changing the SOPs of the input light 4 times. This time-saving and easy-calculating feature is owing to our specific polarimetric camera, where a full-Stokes vector is obtained easily since 3 linear SOPs (0o, 45o, 90o) and 1 circular SOP can be recorded simultaneously by spatially sharing the same detector. To simply verify the effectiveness of our method, a specific polarization device patched by 8 sub-polarizers is chosen as the sample to be measured. Experimental results show that they are consistent with the theoretical results, both in the Mueller matrix and the corresponding images. We predict that this method for Mueller matrix acquisition can get wide potential applications for rapid identifications in biomedicine and material science.
关键词： Division-of-aperture polarimetric camera,Mueller matrix,Liquid crystal variable retarder,Polarization
更新于2025-09-04 15:30:14