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A polarized light sensor is applied to the front-end detection of a biomimetic polarized light navigation system, which is an important part of analyzing the atmospheric polarization mode and realizing biomimetic polarized light navigation, having received extensive attention in recent years. In this paper, biomimetic polarized light navigation in nature, the mechanism of polarized light navigation, point source sensor, imaging sensor, and a sensor based on micro nano machining technology are compared and analyzed, which provides a basis for the optimal selection of different polarized light sensors. The comparison results show that the point source sensor can be divided into basic point source sensor with simple structure and a point source sensor applied to integrated navigation. The imaging sensor can be divided into a simple time-sharing imaging sensor, a real-time amplitude splitting sensor that can detect images of multi-directional polarization angles, a real-time aperture splitting sensor that uses a light field camera, and a real-time focal plane light splitting sensor with high integration. In recent years, with the development of micro and nano machining technology, polarized light sensors are developing towards miniaturization and integration. In view of this, this paper also summarizes the latest progress of polarized light sensors based on micro and nano machining technology. Finally, this paper summarizes the possible future prospects and current challenges of polarized light sensor design, providing a reference for the feasibility selection of different polarized light sensors.

HighlightsThis review summarized the fabrication strategy using circularly polarized light as a chiral source to construct chiral materials.The potential applications of chiral nanomaterials driven by circularly polarized light in different fields are summarized, explained by representative examples.The potential challenges of circularly polarized light-enabled chiral materials are outlined and future research directions are outlooked.For decades, chiral nanomaterials have been extensively studied because of their extraordinary properties. Chiral nanostructures have attracted a lot of interest because of their potential applications including biosensing, asymmetric catalysis, optical devices, and negative index materials. Circularly polarized light (CPL) is the most attractive source for chirality owing to its high availability, and now it has been used as a chiral source for the preparation of chiral matter. In this review, the recent progress in the field of CPL-enabled chiral nanomaterials is summarized. Firstly, the recent advancements in the fabrication of chiral materials using circularly polarized light are described, focusing on the unique strategies. Secondly, an overview of the potential applications of chiral nanomaterials driven by CPL is provided, with a particular emphasis on biosensing, catalysis, and phototherapy. Finally, a perspective on the challenges in the field of CPL-enabled chiral nanomaterials is given.

It is shown that circularly polarized light produces enantiomeric excesses, above 30%, of twisted nanoribbons self-assembled from racemic dispersions of CdTe nanoparticles. The high optical and chemical activity of nanoparticles (NPs) signifies the possibility of converting the spin angular momenta of photons into structural changes in matter. Here, we demonstrate that illumination of dispersions of racemic CdTe NPs with right- (left-)handed circularly polarized light (CPL) induces the formation of right- (left-)handed twisted nanoribbons with an enantiomeric excess exceeding 30%, which is ∼10 times higher than that of typical CPL-induced reactions. Linearly polarized light or dark conditions led instead to straight nanoribbons. CPL ‘templating’ of NP assemblies is based on the enantio-selective photoactivation of chiral NPs and clusters, followed by their photooxidation and self-assembly into nanoribbons with specific helicity as a result of chirality-sensitive interactions between the NPs. The ability of NPs to retain the polarization information of incident photons should open pathways for the synthesis of chiral photonic materials and allow a better understanding of the origins of biomolecular homochirality.

Diffusion MRI is an exquisitely sensitive probe of tissue microstructure, and is currently the only non-invasive measure of the brain's fibre architecture. As this technique becomes more sophisticated and microstructurally informative, there is increasing value in comparing diffusion MRI with microscopic imaging in the same tissue samples. This study compared estimates of fibre orientation dispersion in white matter derived from diffusion MRI to reference measures of dispersion obtained from polarized light imaging and histology. Three post-mortem brain specimens were scanned with diffusion MRI and analyzed with a two-compartment dispersion model. The specimens were then sectioned for microscopy, including polarized light imaging estimates of fibre orientation and histological quantitative estimates of myelin and astrocytes. Dispersion estimates were correlated on region – and voxel-wise levels in the corpus callosum, the centrum semiovale and the corticospinal tract. The region-wise analysis yielded correlation coefficients of r = 0.79 for the diffusion MRI and histology comparison, while r = 0.60 was reported for the comparison with polarized light imaging. In the corpus callosum, we observed a pattern of higher dispersion at the midline compared to its lateral aspects. This pattern was present in all modalities and the dispersion profiles from microscopy and diffusion MRI were highly correlated. The astrocytes appeared to have minor contribution to dispersion observed with diffusion MRI. These results demonstrate that fibre orientation dispersion estimates from diffusion MRI represents the tissue architecture well. Dispersion models might be improved by more faithfully incorporating an informed mapping based on microscopy data.

We investigate the off-resonant circularly polarized light-modulated crossed Andreev reflection (CAR) in an 8-Pmmn borophene-based normal conductor/superconductor/normal conductor junction. When the signs of Fermi energies in two normal regions are opposite, the pure CAR without the local Andreev reflection and the elastic cotunneling occurs. By using the Dirac–Bogoliubov–de Gennes equation and the Blonder–Tinkham–Klapwijk formula, the pure CAR conductance and its oscillation as a function of the junction length and the Fermi energy in the superconducting regions are discussed. It is found that the value of pure CAR conductance peak value and its corresponding value of light-induced gap increase with the increase of incident energy of electron. Furthermore, the valley splitting for the transmitted hole is found due to the presence of tilted velocity of borophene. Our findings are beneficial for designing the high efficiency 8-Pmmn borophene-based nonlocal transistor and nonlocal valley splitter without local and non-entangled processes.

Many reports state the potential hazards of microplastics (MPs) and their implications to wildlife and human health. The presence of MP in the aquatic environment is related to several origins but particularly associated to their occurrence in wastewater effluents. The determination of MP in these complex samples is a challenge. Current analytical procedures for MP monitoring are based on separation and counting by visual observation or mediated with some type of microscopy with further identification by techniques such as Raman or Fourier-transform infrared (FTIR) spectroscopy. In this work, a simple alternative for the separation, counting and identification of MP in wastewater samples is reported. The presented sample preparation technique with further polarized light optical microscopy (PLOM) observation positively identified the vast majority of MP particles occurring in wastewater samples of Montevideo, Uruguay, in the 70–600 μm range. MPs with different shapes and chemical composition were identified by PLOM and confirmed by confocal Raman microscopy. Rapid identification of polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were evidenced. A major limitation was found in the identification of MP from non-birefringent polymers such as PVC (polyvinylchloride). The proposed procedure for MP analysis in wastewater is easy to be implemented at any analytical laboratory. A pilot monitoring of Montevideo WWTP effluents was carried out over 3-month period identifying MP from different chemical identities in the range 5.3–8.2 × 10 3 MP items/m 3 .

Signal transmission between different brain regions requires connecting fiber tracts, the structural basis of the human connectome. In contrast to animal brains, where a multitude of tract tracing methods can be used, magnetic resonance (MR)-based diffusion imaging is presently the only promising approach to study fiber tracts between specific human brain regions. However, this procedure has various inherent restrictions caused by its relatively low spatial resolution. Here, we introduce 3D-polarized light imaging (3D-PLI) to map the three-dimensional course of fiber tracts in the human brain with a resolution at a submillimeter scale based on a voxel size of 100μm isotropic or less. 3D-PLI demonstrates nerve fibers by utilizing their intrinsic birefringence of myelin sheaths surrounding axons. This optical method enables the demonstration of 3D fiber orientations in serial microtome sections of entire human brains. Examples for the feasibility of this novel approach are given here. 3D-PLI enables the study of brain regions of intense fiber crossing in unprecedented detail, and provides an independent evaluation of fiber tracts derived from diffusion imaging data. ►Novel approach to map the 3D courses of fiber tracts in the human brain. ►3D-polarized light imaging (3D-PLI) provides resolution at a submillimeter scale. ►Fiber models were successfully reconstructed in the pontine region. ►3D-PLI provides an independent evaluation of MR-based diffusion imaging data.

Chiral metal nanoclusters (MNCs) are competitive candidates for fabricating circularly polarized light-emitting diodes (CPLEDs), but the device performance is greatly limited by the poor emission of MNCs in solid thin films. Herein, host molecule enhanced aggregation induced emission (AIE) of MNCs is demonstrated for fabricating highly efficient CPLEDs. Namely, on the basis of the AIE effect of atomically precise enantiomeric ( R / S )-4-phenylthiazolidine-2-thione capped silver ( R / S -Ag 6 (PTLT) 6 ) NCs in solid thin films, 1,3-bis(carbazol-9-yl) benzene (mCP) is introduced as a host molecule to control the orientation and packing arrangements of R / S -Ag 6 (PTLT) 6 NCs through π—π interactions with the R / S -Ag 6 (PTLT) 6 NCs and further enhance the AIE. The as-fabricated Ag 6 (PTLT) 6 NC/mCP hybrid solid thin film shows a high photoluminescence quantum yield of 71.0% close to that of Ag 6 (PTLT) 6 NC single crystal. As the hybrid films are employed as the active emission layers of CPLEDs, mCP also suppresses the triplet-triplet annihilation and balances the charge transport. Thus, the CPLEDs exhibit a maximum brightness of 3,906 cd/m 2 , peak external quantum efficiency of 10.0%, and electroluminescence dissymmetry factors of −5.3 × 10 −3 and 4.7 × 10 −3 .

Spin and valley polarizations ( P s and P KK’ ) and tunneling magnetoresistance (TMR) are demonstrated in the ferromagnetic/barrier/normal/barrier/ferromagnetic WSe 2 junction, with the gate voltage and off-resonant circularly polarized light (CPL) applied to the two barrier regions. The minimum incident energy of non-zero spin- and valley-resolved conductance has been derived, which is consistent with numerical calculations and depends on the electric potential U , CPL intensity ΔΩ, exchange field h , and magnetization configuration: parallel (P) or antiparallel (AP). For the P (AP) configuration, the energy region with P KK’  = -1 or P s  = 1 is wider (narrower) and increases with ΔΩ. As h increases, the P s  = 1 ( P KK’  = -1 or P s  = 1) plateau becomes wider (narrower) for the P (AP) configuration. As U increases, the energy region with P KK’  = -1 increases first and then moves parallel to the E F -axis, and the energy region with P s  = 1 for the P configuration remains unchanged first and then decreases. The energy region for TMR = 1 increases rapidly with h , remains unchanged first and then decreases as U increases, and has little dependence on ΔΩ. When the helicity of the CPL reverses, the valley polarization will switch. This work sheds light on the design of spin-valley and TMR devices based on ferromagnetic WSe 2 double-barrier junctions.

Circularly polarized light lasers are attracting growing attention for quantum optics, spin-optoelectronics, and next-generation display technologies. However, despite many demonstrations of cholesteric liquid crystal (CLC) lasers, two challenges remain: achieving broadband and continuous wavelength tunability and quantitatively determining the dissymmetry factor (g) under realistic conditions. Here, we present an actively tunable cholesteric laser based on supersaturated CLC (SCLC) cells driven by electrothermal control. In parallel SCLC cells, lasing wavelengths can be tuned about 130 nm (553–682 nm), but the spectral shift occurs discontinuously due to boundary constraints. In contrast, wedge-shaped SCLC cells form an electrothermally induced pitch gradient that enables rapid and continuous spectral tuning across ~ 100–126 nm. To rigorously quantify the polarization state, we employed the Stokes–Mueller analysis with three circular analyzers, correcting for non-ideal transmission and leakage. Across the full 130-nm tuning range, the generated laser maintained a consistently high degree of circular polarization purity, with the dissymmetry factor g quantified as 1.633 at 600–620 nm and 1.40 at 630–650 nm ranges. These results verify that the circular polarization performance of the SCLC-based tunable laser remains robust throughout the entire visible lasing spectrum. Differential scanning calorimetry further revealed second-order SmA–CLC–isotropic phase transitions, clarifying dynamic asymmetries between heating and cooling and guiding optimal voltage-sweep strategies. Together, these findings demonstrate a reliable pathway toward broadband, color-tunable, and spin-selective CLC lasers, bridging photonic bandgap engineering with practical applications in nanophotonics, spin-optoelectronics, and advanced display technologies.