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Chiral semiconductors, with their distinct photoelectric responses to left- and right-handed circularly polarized light (CPL), are emerging as promising candidates for chiroptical sensing applications. This trend underscores the need to develop chiroptical photoelectric films with tunable handedness. In this study, we report the preparation of parallel-aligned ZnO nanowires (NWs) through oriented electrospinning and subsequent pyrolysis of precursor NWs. Chiral Moiré stacking films were created by stacking ZnO NWs with a controlled left-/right-handed rotation angle between successive layers. The film structural parameters and circular dichroism (CD) spectra were optimized. CPL photodetectors were developed using these chiroptical ZnO NW films and their hybridization with CsPbBr3 perovskite. The photodetector performance was investigated with a focus on responsivity (R), photodetectivity (D*), and the photocurrent asymmetry factor (gIph). Furthermore, discussion on the chiroptical and optoelectronic mechanisms intrinsic to these devices was conducted, shedding light on their potential for advanced CPL photodetection applications. [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL)‐responsive artificial synaptic devices are of significant interest for advanced neuromorphic visual systems, as they enhance perceptual capabilities and enable the development of novel applications. Nevertheless, progress in this field is hindered by the lack of suitable CPL‐active organic semiconductor materials. In this study, environmentally friendly cellulose nanocrystals (CNCs) with a chiral helical structure as a dielectric layer to realize CPL‐resolved behaviors in organic synaptic transistors are utilized. The device exhibits a much stronger response to right‐handed CPL (RCPL) than to left‐handed CPL (LCPL) because the left‐handed helical structure of CNCs reflects LCPL while transmitting RCPL. By modulating electrical and CPL optical signals, the device successfully simulates multiple synaptic activities, including electrical synaptic plasticity, CPL‐dependent optical synaptic plasticity, and brain‐like learning and memory behavior controlled by photoelectric cooperative stimulation. Additionally, the device demonstrates applications in blue‐light‐induced visual fatigue simulation, CPL recognition, and optical wireless encrypted communication. Importantly, the sensitivity of the device to CPL is not constrained by the properties of organic semiconductor materials. These findings offer a promising strategy for the development of advanced artificial synaptic devices and CPL‐resolved neuromorphic visual systems. [ABSTRACT FROM AUTHOR]

Spin and valley polarizations (Ps and PKK') and tunneling magnetoresistance (TMR) are demonstrated in the ferromagnetic/barrier/normal/barrier/ferromagnetic WSe2 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 PKK' = -1 or Ps = 1 is wider (narrower) and increases with ΔΩ. As h increases, the Ps = 1 (PKK' = -1 or Ps = 1) plateau becomes wider (narrower) for the P (AP) configuration. As U increases, the energy region with PKK' = -1 increases first and then moves parallel to the EF-axis, and the energy region with Ps = 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 WSe2 double-barrier junctions. [ABSTRACT FROM AUTHOR]

Helicenes and helicenoid structures are promising candidates for future applications exploiting circularly polarized light. Ideal candidates should possess near‐quantitative photoluminescence quantum yield, a high luminescence dissymmetry factor and an adjustable HOMO‐LUMO gap. However, carbo[n]helicenes are poorly luminescent compounds and they absorb light mainly in the ultraviolet region. Here we show that the incorporation of a carbonyl group into helical scaffold significantly improves the fluorescence quantum yield and shifts the absorption to visible region. Although the carbonyl group is commonly considered as detrimental to efficient emission, fluorescence quantum yields up to Φ=0.43 were recorded. A straightforward synthetic approach to a highly luminescent tetraceno[6]helicenone and an aza analogue has been developed. The key step is a radical cyclization which is achieving dehydrative π‐extension. The aza‐analogue was incorporated as an emitter in organic light emitting diodes (OLEDs) and showed good performance. [ABSTRACT FROM AUTHOR]

Rotational motion of charges in plasmonic nanostructures plays an important role in transferring angular momentum between light and matter on the nanometer scale. Although sophisticated control of rotational charge motion has been achieved using spatially structured light, its extension to simultaneous excitation of the same charge motion in multiple nanostructures is not straightforward. In this study, we perform model calculations to show that spatially homogeneous circularly polarized (CP) light can excite rotational charge motions with a high degrees of freedom by exploiting the rotational symmetry of the plasmonic structure and that of the plasmon mode. Finite-difference time-domain simulations demonstrate selective excitation of rotational charge motion for both isolated nanoplates and periodic array structures, showing that complex charge rotations can be manipulated by plane CP waves in a wide range of plasmonic structures. [ABSTRACT FROM AUTHOR]

Chiral plasmonic nanoantennas exhibit unique chiroptical properties in both the near‐field and far‐field, offering exciting opportunities for applications in chiroptical sensing, circularly polarized luminescence, and quantum communication. Recent advances in chiral plasmonics have facilitated the creation of nanoparticles with intrinsic chirality at the single‐particle level. However, the far‐field directionality of these chiral nanoantennas is not well understood. In this work, A numerical study is conducted on a single plasmonic nanoantenna that undergoes a size‐preserving compression, transitioning from a straight nanorod to left‐ or right‐handed helices with varying pitches. These nanostructures showcase distinct mode‐dependent chiroptical far‐field properties, encompassing positive or negative dissymmetry factors, 3D power radiation patterns, and angular distribution of circular polarization, under both plane‐wave and point‐source excitations. The findings provide new insights into angle‐resolved spectroscopies of intrinsically chiral plasmonic nanoparticles and the applications of chiral plasmonic nanoantennas for controlling circularly polarized light emission in nanophotonics. [ABSTRACT FROM AUTHOR]

The maintenance of triplet excitons to produce room‐temperature phosphorescence while simultaneously improving the luminescence dissymmetry factor (glum) and photoluminescence quantum yield (PLQY) makes the preparation of circularly polarized room‐temperature phosphorescence (CP‐RTP) materials challenging. Herein, two chiral cocrystals are reported with CP‐RTP using S/R‐1‐(1‐Naphthyl)ethanol (S/R‐1‐nea) as the donor and 1,2,4,5‐Tetracyanobenzene (TCNB) as the acceptor. Simultaneous enhancement of glum and PLQY is accomplished, with the greatest phosphorescence in the PLQY of ≈31% and |glum| of 0.065, which is one of the highest |glum| in cocrystals. Doping two chiral cocrystals into the polyvinyl alcohol (PVA) matrix resulted in polymer films with circularly polarized long afterglow luminescence, indicating the potential for multilevel encryption applications. This study provides a novel approach to achieve the dual improvement of glum and phosphorescence PLQY, and broadens the application prospects of CP‐RTP materials. [ABSTRACT FROM AUTHOR]

Low‐dimensional hybrid metal halides (LDHMHs) have emerged as a highly promising class of functional materials for a wide range of optoelectronic applications. Their exceptional structural tunability, facilitated by the hybridization of metal halides with organic compounds, enables the formation of three‐, two‐, one‐, or zero‐dimensional structures. This flexibility in structural design also allows the incorporation of chirality into the crystalline lattice, giving rise to novel LDHMH materials that are capable of selectively interacting with the spin angular momentum of electrons and photons. Among the unique optoelectronic properties of LDHMHs, the focus of this concept article is their chiroptical nonlinear optical (NLO) effect. LDHMHs demonstrate a highly effective discrimination and generation of circularly polarized (CP) light in the NLO regime, particularly in the second harmonic generation (SHG) process, referred to as SHG‐circular dichroism (SHG‐CD) and CP‐SHG. These anisotropic responses are several orders of magnitude larger than linear chiroptical responses, such as CD and CP luminescence; consequently, LDHMHs are expected to be promising candidates for future optical‐information devices and encryption systems. This article introduces recently reported chiral LDHMH materials that exhibit excellent CP‐dependent anisotropic SHG responses. [ABSTRACT FROM AUTHOR]

Chiral catalysts for asymmetric catalysis represent a crucial research focus in chemistry and materials science. However, a few cases about chiral‐dependent photocatalysts primarily focus on plasmonic noble metals. Particularly, developing chiral nano‐catalysts that can be driven by mechanical energy remains in the blank stage. Herein, organic polymer‐based enantiomers, chiral polar polyimide (PI) microspheric nano‐assembly are synthesized as novel bifunctional catalysts for asymmetric photocatalysis and piezocatalysis. The PI catalyst enantiomers present enantioselectivity towards left‐ and right‐circularly polarized light, demonstrating chiral‐dependent H2O2 photoproduction. Interestingly, enantioselectivity of the catalyst reverses under irradiation of different bands, presenting tunability in the interaction between chiral catalysts and circularly polarized light. For the first time, enantioselective piezocatalytic behavior is demonstrated by the chiral polar PI catalysts. They show remarkable chiral preference for asymmetric Diels–Alder reaction and enantioselective conversion of tyrosine substrates under ultrasonic vibration. The findings provide a new perspective into exploring metal‐free chiral catalysts and their asymmetric catalysis applications across multiple energy forms. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To fully understand the physics of chiro-optical systems and to derive their potentials, it is essential to observe chiro-optical effects in situ from individual components, since the macroscopic chiro-optical effects cannot be directly translated into the microscopic effects. Here, we observed optical responses at the nanoscale level by detecting optical forces induced by irradiating circularly polarized light onto a tip-sample system. The induced optical forces were well correlated with the differential intensity of the simulated electric field. [ABSTRACT FROM AUTHOR]

Copyright of Micronanoelectronic Technology is the property of Micronanoelectronic Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Circularly polarized light (CPL) has attracted great attention due to its unique electromagnetic vector, which possesses potential practical applications in optical imaging, biometrics, and other interdisciplinary areas. At present, many materials with spontaneous CPL emitting have been extensively studied and reviewed for the generation of CPL. For the detection of CPL, mainly concentrate on the technical problems, that is, how to combine circularly polarized optical active materials with device structures to meet detection needs. Essentially, the resolution of CPL depends on the interaction between CPL and matter, Herein, the interactive modes including polarized light‐spin and light‐dipole (or charge) interactions in devices are summarized. Also, direct and indirect interactions of polarized light‐spin are presented. Meanwhile, the progress of light‐spin/dipole interaction dependence of CPL detectors is analyzed based on artificial structures of photoconductors, photodiodes, and photo field effect transistors. It is hoped that the review can broaden the bridge between the fundamental photon‐spin‐dipole interaction and CPL detectors with high performance, and then deepen the understanding of CPL detection and promote the development of CPL detectors. [ABSTRACT FROM AUTHOR]

Chiral photocatalytic nanomaterials possess numerous unique properties and hold promise for various applications in chemical synthesis, environmental protection, energy conversion, and photoelectric devices. Nevertheless, it is uncommon to develop effective means to enhance the asymmetric catalytic performances of chiral plasmonic nanomaterials. In this study, a type of L/D‐Au@CeO2 helical nanorods (HNRs) was fabricated by selectively growing CeO2 on the surface of Au HNRs via a facile wet‐chemistry construction method. Chiral Au@CeO2 HNRs, featuring Au and CeO2 with spatially separated structures, exhibited the highest photocatalytic performance for N2 fixation, being 50.80±2.64 times greater than that of Au HNRs. Furthermore, when L‐Au@CeO2 HNRs were exposed to left circularly polarized light (CPL) and D‐Au@CeO2 HNRs were exposed to right CPL, their photocatalytic efficiency was enhanced by 3.06±0.06 times compared to the samples illuminated with the opposite CPL, which can be attributed to the asymmetrical generation of hot carriers upon CPL excitation. This study not only offers a simple approach to enhance the photocatalytic performance of chiral plasmonic nanomaterials but also demonstrates the potential of chiral plasmonic materials for application in specific photocatalytic reactions, such as N2 fixation. [ABSTRACT FROM AUTHOR]

Abstract Circularly polarized light (CPL) is inherently chiral and is regarded as one possible source for the origin of homochirality. Coincidentally, chiral metal nanoparticles have great prospects in asymmetric photochemical reactions since they can enhance the chiral light‐matter interactions. Nonetheless, little is known about how the spin angular momentum of light competes with the chiral electromagnetic field in the vicinity of a chiral nanoparticle during the chiral induction and amplification process. Here, an asymmetric photo‐polymerization system is presented where the chiral bias can be selectively regulated by the combination of chiral fields CPL and Ag nanoparticles, either constructively or destructively. Synergistic chiral amplification effect is observed when the handedness of both are matched, while the opposite‐handed CPL can overrule the polymer helicity during the chain propagation process when the chiral near‐field is weak. There is a bifurcation point in the chiral bias for the orthogonal control of the polymer helicity during the asymmetric photo‐polymerization process, favoring for programmable chiroptical micropatterns and multi‐channel independent information encoding. This work not only highlights opportunities for selectively regulating the asymmetric photopolymerization but also is highly valuable for fundamental understanding of the symmetry breaking in photochemical reactions.

Cellulose nanocrystal (CNC), as a typical natural photonic crystal material with outstanding advantages, has attracted increasing interests to develop stimulus‐responsive materials with vivid structural colors and circularly polarized light manipulators with high dissymmetry factors for widespread applications. However, limited by its spontaneous left‐handed cholesteric phase and absent right‐handed helical structure, current CNC‐based optical materials mainly achieve the selective reflection of left‐handed circularly polarized light (L‐CP) and the transmission of right‐handed circularly polarized light (R‐CP). Opposite to all reported intrinsic chirality in CNC assemblies, here first prominent twisted right‐handed helix in solid CNC film is found which is prepared through dynamically rotational self‐assembly. The dynamic rotation drives CNC particles to form a right‐handed helix with pitches of sub‐micron level regardless of rotary direction, realizing an ambidextrous reflection of both L‐CP and R‐CP for CNC film with maintained intrinsic structural color, and the first example of inversed right‐handed helix in CNC is further demonstrated. Moreover, the CNC films highly depend on the light propagation direction in term of apparent circular dichroism signals, presenting an exciting prospect for developing quantum transduction. This work is believed a breakthrough on chiral CNC photonic materials, providing new insights and application prospects for chiral CNC materials. [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL) detection is of great significance in various applications such as drug identification, sensing and imaging. Atomically precise chiral metal nanoclusters with intense circular dichroism (CD) signals are promising candidates for CPL detection, which can further facilitate device miniaturization and integration. Herein, we report the preparation of a pair of optically active chiral silver nanoclusters [Ag7(R/S‐DMA)2(dpppy)3] (BF4)3 (R/S‐Ag7) for direct CPL detection. The crystal structure and molecular formula of R/S‐Ag7 clusters are confirmed by single‐crystal X‐ray diffraction and high‐resolution mass spectrometry. R/S‐Ag7 clusters exhibit strong CD spectra and CPL both in solution and solid states. When used as the photoactive materials in photodetectors, R/S‐Ag7 enables effective discrimination between left‐handed circularly polarized and right‐handed circularly polarized light at 520 nm with short response time, high responsivity and considerable discrimination ratio. This study is the first report on using atomically precise chiral metal nanoclusters for CPL detection. [ABSTRACT FROM AUTHOR]

In chemistry and biochemistry, chirality represents the structural asymmetry characterized by nonsuperimposable mirror images for a material such as DNA. In physics, however, chirality commonly refers to the spin–momentum locking of a particle or quasiparticle in the momentum space. While seemingly disconnected, structural chirality in molecules and crystals can drive electronic chirality through orbital–momentum locking; that is, chirality can be transferred from the atomic geometry to electronic orbitals. Electronic chirality provides an insightful understanding of chirality-induced spin selectivity, in which electrons exhibit salient spin polarization after going through a chiral material, and electrical magnetochiral anisotropy, which is characterized by diode-like transport. It further gives rise to new phenomena, such as anomalous circularly polarized light emission, in which the light handedness relies on the emission direction. These chirality-driven effects will generate broad impacts for fundamental science and technology applications in spintronics, optoelectronics, and biochemistry. [ABSTRACT FROM AUTHOR]

Ultrafast nanophotonics is a rapidly growing area of study focused on creating nanodevices that can modulate the properties of light at, to this date, unparalleled speed. To facilitate the growth of this field, there is a growing need for compact metamaterial designs for the manipulation of the amplitude, phase, and polarization of light. One promising strategy involves leveraging the optical nonlinearity of nanostructured materials to alter their permittivity by interacting with high‐intensity ultrashort laser pulses. This study showcases how such requirements can be met through the utilization of 2D materials, particularly graphene. The nonlinear optical response of a graphene nanorectangle array is theoretically modeled to achieve all‐optical, fully reversible, broadband, and ultrafast dynamic control of light chirality. This is achieved by taking advantage of the energy relaxation dynamics of coherently excited localized plasmons supported by the metasurface, and the transient increase in electron temperature in graphene. Using finite‐difference time‐domain simulations, ultrafast dynamic tuning between circular and linearly polarized light is demonstrated. The proposed platform gives promise for ultrathin, CMOS‐compatible nanophotonic systems that can provide high‐speed, room‐temperature modulation of light polarization. [ABSTRACT FROM AUTHOR]

Optically active poly(naphthalene‐1,4‐diyl) was prepared through helix–sense–selective polymerization of the corresponding monomers and also through circularly polarized light (CPL) irradiation, resulting in distinctive circular dichroism (CD) spectral patterns. Chirality of the helix–sense–selective polymerization ‐based polymer is ascribed to preferred–handed helicity while that of the CPL–based polymer to a non–helical, chiral conformation ('biased–dihedral conformation') with preferred–handedness which was stable only in the solid state. The helix of the helix–sense–selective polymerization–based polymer gradually racemized in tetrahydrofuran while it was stabilized by aggregate formation in a hexane–dichloromethane solution. Both helix–sense–selective polymerization‐ and CPL–based polymers exhibited efficient circularly polarized luminescence. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The chiral organic–inorganic halide perovskites (OIHPs) are vital candidates for superior nonlinear optical (NLO) effects associated with circularly polarized (CP) light. NLO in chiral materials often couples with magnetic dipole (MD) transition, as well as the conventional electric dipole (ED) transition. However, the importance of MD transition in NLO process of chiral OIHPs has not yet been well recognized. Here, the circular polarized probe analysis of second harmonic generation circular dichroism (SHG‐CD) provides the direct evidence that the contribution of MD leads to a large anisotropic response to CP lights in chiral OIHPs, (R‐/S‐MBACl)2PbI4. The thin films exhibit great sensitivity to CP lights over a wide wavelength range, and the g‐value reaches up to 1.57 at the wavelength where the contribution of MD is maximized. Furthermore, it is also effective as CP light generator, outputting CP‐SHG with maximum g‐factor of 1.76 upon the stimulation of linearly polarized light. This study deepens the understanding of relation between chirality and magneto‐optical effect, and such an efficient discrimination and generation of CP light signal is highly applicable for chirality‐based sensor and optical communication devices. [ABSTRACT FROM AUTHOR]

Significance: Phase retardation of circularly polarized light (CPL), backscattered by biological tissue, is used extensively for quantitative evaluation of cervical intraepithelial neoplasia, presence of senile Alzheimer's plaques, and characterization of biotissues with optical anisotropy. The Stokes polarimetry and Mueller matrix approaches demonstrate high potential in definitive non-invasive cancer diagnosis and tissue characterization. The ultimate understanding of CPL interaction with tissues is essential for advancing medical diagnostics, optical imaging, therapeutic applications, and the development of optical instruments and devices. Aim: We investigate propagation of CPL within turbid tissue-like scattering medium utilizing a combination of Jones and Stokes--Mueller formalisms in a Monte Carlo (MC) modeling approach. We explore the fundamentals of CPL memory effect and depolarization formation. Approach: The generalized MC computational approach developed for polarization tracking within turbid tissue-like scattering medium is based on the iterative solution of the Bethe--Salpeter equation. The approach handles helicity response of CPL scattered in turbid medium and provides explicit expressions for assessment of its polarization state. Results: Evolution of CPL backscattered by tissue-like medium at different conditions of observation in terms of source--detector configuration is assessed quantitatively. The depolarization of light is presented in terms of the coherence matrix and Stokes--Mueller formalism. The obtained results reveal the origins of the helicity flip of CPL depending on the source--detector configuration and the properties of the medium and are in a good agreement with the experiment. Conclusions: By integrating Jones and Stokes--Mueller formalisms, the combined MC approach allows for a more complete representation of polarization effects in complex optical systems. The developed model is suitable to imitate propagation of the light beams of different shape and profile, including Gaussian, Bessel, Hermite--Gaussian, and Laguerre--Gaussian beams, within tissue-like medium. Diverse configuration of the experimental conditions, coherent properties of light, and peculiarities of polarization can be also taken into account. [ABSTRACT FROM AUTHOR]

Technologies that detect circularly polarized light (CPL), particularly in the UV region, have significant potential for various applications, including bioimaging and optical communication. However, a major challenge in directly sensing CPL arises from the conflicting requirements of planar structures for efficient charge transport and distorted structures for effective interaction with CPL. Here, a novel design of an axially chiral n‐type organic semiconductor is presented to surmount the challenge, in which a binaphthyl group results in a high dissymmetry factor at the molecular level, while maintaining excellent electron‐transporting characteristics through the naphthalene diimide group. Experimental and computational methods reveal different stacking behaviors in homochiral and heterochiral assemblies, yielding different structures: Nanowires and nanoparticles, respectively. Especially, the homochiral assemblies exhibit effective π–π stacking between naphthalene diimides despite axial chirality. Thus, phototransistors fabricated using enantiomers exhibit a high maximum electron mobility of 0.22 cm2 V−1 s−1 and a detectivity of 3.9 × 1012 Jones, alongside the CPL distinguishing ability with a dissymmetry factor of responsivity of 0.05. Furthermore, the material possesses a wide bandgap, contributing to its excellent visible‐blind UV‐selective detection. These findings highlight the new strategy for compact CPL detectors, coupled with the demonstration of less‐explored n‐type and UV region phototransistors. [ABSTRACT FROM AUTHOR]

Polarization sensitive optical coherence tomography (PSOCT) makes use of the birefringence information of the sample to compensate for the lack of internal tissue-specific contrast in conventional optical coherence tomography (OCT). Circularly polarized light is always used as an incident beam in PSOCT, but it is difficult to have perfect in practice. The manual calibration method of circularly polarized light suffers from the problems of complicated calibration operation and lack of stability. This study proposes a simple method to enhance the imaging of PSOCT without altering the system. A numerical calibration of circularly polarized light can be implemented using the original system setup, ensuring that the system's complexity remains unchanged. Enhancements in imaging quality can be achieved through an algorithmic analysis of the captured interference fringe data. This calibration is applied in the field map of interference data before being quadrature-assembled. Notably, the proposed approach achieves high sensitivity in PSOCT. The birefringence image shows a more obvious layered structure. Improvements in the signal-to-noise ratio (SNR) were demonstrated for chicken breast, pork, and beef imaging at about 20 dB. [ABSTRACT FROM AUTHOR]

Glycerophospholipid membranes are one of the key cellular components. Still, their species‐dependent composition and homochirality remain an elusive subject. In the context of the astrophysical circularly polarized light scenario likely involved in the generation of a chiral bias in meteoritic amino and sugar acids in space, and consequently in the origin of life's homochirality on Earth, this study reports the first measurements of circular dichroism and anisotropy spectra of a selection of glycerophospholipids, their chiral backbones and their analogs. The rather low asymmetry in the interaction of UV/VUV circularly polarized light with sn‐glycerol‐1/3‐phosphate indicates that chiral photons would have been unlikely to directly induce symmetry breaking to membrane lipids. In contrast, the anisotropy spectra of d‐3‐phosphoglyceric acid and d‐glyceraldehyde‐3‐phosphate unveil up to 20 and 100 times higher maximum anisotropy factor values, respectively. This first experimental report, targeted on investigating the origins of phospholipid symmetry breaking, opens up new avenues of research to explore alternative mechanisms leading to membrane lipid homochirality, while providing important clues for the search for chiral biosignatures of extant and/or extinct life in space, in particular for the ExoMars 2028 mission. [ABSTRACT FROM AUTHOR]

The traditional underwater active polarization imaging system primarily employs linearly polarized light as its illumination source. However, in cases where the target exhibits high light polarization upon reflection in a turbid medium, the difference between the polarization of the target’s reflected light and that of the backscattered light in the turbid water becomes small. This can result in the backscattered light intensity sampled per unit pixel exceeding that of the target, significantly degrading image quality. To address this issue, this paper introduces an underwater target imaging method based on active circularly polarized light. This method capitalizes on the superior polarization-preserving characteristics of circularly polarized light relative to linearly polarized light, along with the spin reversal of circularly polarized reflected light. Based on these properties, combined with circularly polarized differential imaging method and image frequency domain filtering method, the method in this paper can realize the recovery of target images with highly reflected polarized light in turbid waters. The performance of the algorithm described in this paper is assessed through simulation experiments and validated via laboratory tests, demonstrating the superior effectiveness of the proposed method compared to previous approaches.

In this work, a biosensor based on a structurally chiral medium (SCM) under the effect of a low-frequency electric field has been designed to detect blood hemoglobin. The introduced structure is irradiated with a circularly polarized light under an electro-optical Pockels effect. A photonic band gap is observed in the transmission spectrum of the right-handed circularly polarized waves, which indicates the circular Bragg phenomenon. The sensor consists of a sample layer sandwiched between two identical SCMs. Sensor performance is evaluated using the transfer matrix method (TMM). The results show that the defect mode is sensitive to any change in the refractive index of the defect layer where the defect layer is infiltrated with samples with different concentrations of blood hemoglobin. Also, it is shown that applying a low-frequency electric field increases the sensitivity of the mentioned sensor. It is observed that the sensitivity can be expanded up to 142.66 nm/RIU by changing the various parameters of the SCM.

A dielectric nanosphere with orthogonal electric dipole (ED) and magnetic dipole (MD) Mie resonances can be a nanoantenna radiating circularly polarized light in specific directions if the amplitudes and the phase relations are properly designed. First, theoretical calculations show that a silicon nanosphere illuminated with a linearly polarized plane wave radiates circularly polarized light at the wavelength in between the ED and MD resonances if the refractive index of a surrounding medium (nm) is ≈1.3; the ellipticity of the scattered light can be >0.99 when nm is in a 1.19–1.35 range. Size‐purified silicon nanospheres suspended in water (nm = 1.33) are then prepared, and the angle‐ and circular‐polarization‐resolved scattering spectra are studied. It is experimentally demonstrated that circularly polarized light is radiated in specific directions under linearly polarized plane wave illumination. The results also show that the wavelength of the radiation of circularly polarized light can be controlled in the whole visible range by controlling the silicon nanosphere diameter in 100–200 nm range. [ABSTRACT FROM AUTHOR]

Micro-sized chiral-nematic liquid crystal (N* LC) polymer particles have attracted considerable interest as versatile reflective colorants with selective circularly polarized light (CPL) properties. However, challenges in achieving the desired size distribution of N* LC particles have led to an incomplete understanding of their reflective characteristics. In this study, we successfully synthesized N* LC particles via dispersion polymerization, enabling precise control over size polydispersity by manipulating the composition of the polymerization solvent. Our investigation revealed that monodisperse N* LC particles displayed distinct reflection bands with high CPL selectivity, while polydisperse particles exhibited broader reflection with lower CPL selectivity. These findings underscore the potential to synthesize N* LC particles with tailored reflective properties using identical monomeric compounds. Furthermore, we demonstrated the production of multifunctional reflective colorants by blending N* LC particles with varying reflection colors. These discoveries hold significant promise for advancing the development of reflective colorants and anti-counterfeiting printing techniques utilizing micro-sized N* LC particles. [ABSTRACT FROM AUTHOR]

The generation and detection of circularly polarized light (CPL) are of importance in many modern technologies such as digital communications, machine vision, bio-imaging, and 3D displays. In this study, inspired by the fact that various species of plants and animals can efficiently produce and/or perceive CPL with chiral photonic crystal structures, efforts are made to fabricate luminescent chiral photonic crystals with caesium lead halide perovskites, a class of solution-processable semiconductors that have excellent luminescence properties and readily tunable electronic band gaps. Coupling between the emission frequency of the perovskite and the cavity resonance frequency of the photonic crystal structure can be established at any desired point in the visible region, giving rise to CPL output with a dissymmetry factor up to −0.34. These results suggest a new approach to chiral light-emitting materials and may contribute to the development of semiconductors with ordered microstructures. [ABSTRACT FROM AUTHOR]

Chiral liquid crystal elastomers (CLCEs) are soft photonic materials that exhibit both the photonic characteristics of nanoscale periodic helical structures and mechanical properties of rubber. Owing to its elasticity, the structural color of CLCEs can be tuned through mechanical deformations known as mechanochromism. Thus far, there is significant research attention to exploring the mechanochromism of CLCEs. However, most studies have only discussed the color shifting of CLCEs under uniaxial deformation. Therefore, the optical and chiral structural deformation behaviors of CLCEs under multiaxial stress are not well understood. This study investigates multiaxial (uniaxial, biaxial, and out‐of‐plane) stretching‐induced helical structure change and the resulting optical properties of CLCEs. The results confirm that uniaxial stretching leads to a loss of intrinsic circular polarization selectivity in CLCEs due to helix unwinding deformations, while biaxial and out‐of‐plane stretching maintain circular polarization. [ABSTRACT FROM AUTHOR]

Realizing high photoluminescence quantum yield (PLQY) in the near‐infrared (NIR) region is challenging and valuable for luminescent material, especially for thermally activated delay fluorescence (TADF) material. In this work, we report two achiral cyclic trinuclear Au(I) complexes, Au3(4‐Clpyrazolate)3 and Au3(4‐Brpyrazolate)3 (denoted as Cl−Au and Br−Au), obtained through the reaction of 4‐chloro‐1H‐pyrazole and 4‐bromo‐1H‐pyrazole with Au(I) salts, respectively. Both Cl−Au and Br−Au exhibit TADF with high PLQY (>70 %) in the NIR I (700–900 nm) (λmax = 720 nm) region, exceeding other NIR−TADF emitters in the solid state. Photophysical experiments and theoretical calculations confirmed the efficient NIR−TADF properties of Cl−Au and Br−Au were attributed to the small energy gap ΔE(S1‐T2) (S = singlet, T = triplet) and the large spin‐orbital coupling induced by ligand‐to‐metal‐metal charge transfer of molecular aggregations. In addition, both complexes crystallize in the achiral Pna21 space group (mm2 point group) and are circularly polarized light (CPL) active with maxima luminescent dissymmetry factor |glum| of 3.4 × 10−3 (Cl−Au) and 2.7 × 10−3 (Br−Au) for their crystalline powder samples, respectively. By using Cl−Au as the emitting ink, 3D‐printed luminescent logos are fabricated, which own anti‐counterfeiting functions due to its CPL behavior dependent on the crystallinity. [ABSTRACT FROM AUTHOR]

We show fledgling quantum spin Hall phase by the normal incidence of near-infrared circularly polarized radiation field on Bismuth Selenide doped with magnetic impurities. For this purpose, we start with a low-energy twodimensional, time-dependent Hamiltonian. The time dependence in the Hamiltonian arises due to the optical field describable by the associated gauge field. We make use of the Floquet theory in the high-frequency limit to investigate the system. The optical field tuneability leads to the emergence of the spin Hall phase, when intensity of the incident radiation is high, from the quantum anomalous Hall phase. Interestingly, the former phase is achievable here even in the presence of the magnetic impurities. [ABSTRACT FROM AUTHOR]

Conventional mirrors flip the handedness of circularly polarized light upon reflection. However, there is an increasing demand for the design and fabrication of handedness‐preserving mirrors as well as chiral reflective metasurfaces with tunable spin states of reflected photons that work in a broad wavelength range in the UV and visible domain. Most chiral mirrors fabricated up to now are prepared by top‐down techniques, such as e‐beam lithography, which are very costly and difficult to scale up to macroscopic devices. Here, an efficient bottom‐up strategy is introduced for fabricating chiral mirrors by using Layer‐by‐Layer assembly of oriented silver nanowire layers prepared by grazing incidence spraying on a semi‐reflective silver layer. The resulting chiral metasurfaces display structure‐dependent differential reflectance for circularly polarized light in a broad wavelength range in the UV, visible, and near infrared domains, reaching an extremely high figure of merit. Their differential reflectance reaches up to 95% of the maximum polarization efficiency, with the handedness of the reflected light being partially preserved. These large‐area chiral mirrors with tunable chiral reflectance open perspectives in various fields, such as in optics, sensing, and chiral light‐matter interactions. [ABSTRACT FROM AUTHOR]

High‐performance chiroptical synaptic phototransistors are successfully demonstrated using heterojunctions composed of a self‐assembled nanohelix of a π‐conjugated molecule and a metal oxide semiconductor. To impart strong chiroptical activity to the device, a diketopyrrolopyrrole‐based π‐conjugated molecule decorated with chiral glutamic acid is newly synthesized; this molecule is capable of supramolecular self‐assembly through noncovalent intermolecular interactions. In particular, nanohelix formed by intertwinded fibers with strong and stable chiroptical activity in a solid‐film state are obtained through hydrogen‐bonding‐driven, gelation‐assisted self‐assembly. Phototransistors based on interfacial charge transfer at the heterojunction from the chiroptical nanohelix to the metal oxide semiconductor show excellent chiroptical detection with a high photocurrent dissymmetry factor of 1.97 and a high photoresponsivity of 218 A W−1. The chiroptical phototransistor demonstrates photonic synapse‐like, time‐dependent photocurrent generation, along with persistent photoconductivity, which is attributed to the interfacial charge trapping. Through the advantage of synaptic functionality, a trained convolutional neural network successfully recognizes noise‐reduced circularly polarized images of handwritten alphabetic characters with better than 89.7% accuracy. [ABSTRACT FROM AUTHOR]

Circularly polarized light in the second near-infrared window (NIR-II CPL) features a unique set of advantages such as deep penetration depth and reduced light absorption, which holds promising potentials for biomedical applications. To date, high-performance NIR-II CPL materials remain challenging to construct. Here, we report that the application of ultrasonication to cellulose nanocrystal (CNC) suspensions red-shifts the film photonic bandgap to the NIR region; in concurrent, focal conic phase forms whose intercalation within self-assembled chiral nematic CNC films can be eliminated by keeping the film thickness below a critical value. We present that multilayer lamination of thin CNC films absence of focal conic phase affords a general approach to produce right-handed NIR-II CPL with the degree of circular polarization of 0.556 at 1430 nm. Finally, we demonstrate that the right-handed CPL at 1430 nm of the laminated CNC film offers an extra optical diagnostic tool for the discrimination of human cancer tissues. [ABSTRACT FROM AUTHOR]

Highlights This 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.

The selective synthesis of nickel and copper complexes of 19‐benzoyl‐5,10,15‐triphenyl‐bilatrien‐1‐one (H2TPBT) is reported, a molecule which crystallizes as a molecular helix of one‐and‐a‐quarter which turns with a 5.7 Å radius and a 3.2 Å pitch, and all 26 participating atoms are sp2‐hybridized. UV/vis, ECD, ESR and cyclic voltammetry experiments reveal a strong interaction between metal and ligand and partial radical character when copper is coordinated instead of nickel. Strong ECD absorption in the 800 nm range is found which, using TD‐DFT calculations as well as literature spectra, is shown to be highly tunable both by metal coordination and variation of the aryl groups in the TPBT periphery. The radical character of the ligand in Cu(TPBT) enables rapid interconversion between (M)‐ and (P)‐enantiomers, possibly via intermittent breakage of a Cu−N bond. The 19‐benzoyl group kinetically stabilizes enantiopure (M/P)‐Ni(TPBT). The results are interpreted with regard to the application as circularly polarized light (CPL) detectors as well as to the chirality‐induced spin‐selectivity (CISS) effect which is currently lacking a concise theoretical model. [ABSTRACT FROM AUTHOR]

A silicon-nanostructured array coating on silicon film (SAS film) is designed based on the plasmonic optical tweezer and demonstrated for optical trapping and manipulation of nanospheres with negligible impact on the local thermal conditions. The electric field enhancement, optical force, and trapping potential of the SAS film are investigated by the finite element method. The trapping position is affected by the incident light wavelength, structure of the nanoarray, and refractive index of the nanospheres. The presence of four energy wells around the nanoarray suggests that it is possible to trap multiple nanoparticles. Moreover, the circularly polarized light, Gaussian beam, and silicon nanoarray facilitate the trapping of nanoparticles. This study showcases the potential of SAS film as optical tweezers to capture nanoparticles for the development of nanophotonic devices. [ABSTRACT FROM AUTHOR]

Optically active, hyperbranched, poly(fluorene‐2,4,7‐triylethene‐1,2‐diyl) [poly(fluorenevinylene)] derivatives bearing a neomenthyl group and a pentyl group at the 9‐position of the fluorene backbone at various ratios acted as a chirality donor (host polymers) efficiently included naphthalene, anthracene, pyrene, 9‐phenylanthracene, and 9,10‐diphenyanthracene as a chirality acceptor (guest molecules) in their interior space in film as well as in solution, with the guest molecules exhibiting intense circular dichroism through chirality transfer with chirality amplification. The efficiency of the chirality transfer was much higher with higher‐molar‐mass polymers than lower‐molar‐mass ones as well as with hyperbranched polymers compared to the analogous linear ones. The hyperbranched polymers include the small molecules in their complex structure without any specific interactions at various stoichiometries. The included molecules may have ordered intermolecular arrangement that may be somewhat similar to those of liquid crystals. Naphthalene, anthracene, and pyrene included in the polymer exhibited efficient circularly polarized luminescence, where the chirality was remarkably amplified in excited states, and anthracene exhibited especially high anisotropies in the emission on the order of 10−2. [ABSTRACT FROM AUTHOR]

Structural coloration has become a fascinating field of research, inspiring scientists and engineers to explore the vibrant colors observed in nature and develop bio-inspired photonic structures for various applications. Cellulose-based materials derived from plant fibers offer a promising platform for mimicking natural photonic structures. Their abundance, renewability, and versatility in form and structure make them ideal for engineering specific optical properties. Self-assembly techniques enable the creation of ordered, periodic structures at the nanoscale by manipulating the interactions between cellulose fibers through chemical modification or physical manipulation. Alternatively, additive manufacturing techniques like 3D printing and nanoimprint lithography can directly fabricate desired structures. By em-ulating natural photonic structures, cellulose-based materials hold immense potential for applications such as colorimetric sensors, optoelectronic devices, camouflage, and decorative materials. However, further research is needed to fully com-prehend and control their optical properties, as well as develop cost-effective and scalable manufacturing processes. This article presents a comprehensive review of the fundaments behind natural structural colors exhibited by living organisms and their bio-inspired artificial counterparts. Emphasis is placed on understanding the underlying mechanisms, strategies for tunability, and potential applications of these photonic nanostructures, with special focus on the utilization of cellulose nanocrystals (CNCs) for fabricating photonic materials with visible structural color. The challenges and future prospects of these materials are also discussed, highlighting the potential for advancements to unlock the full potential of cellulose-based materials with structural color. [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL) has attracted considerable interest since it can impart chiral bias into photochemical reactions and open up a novel opportunity for synthesizing chiral polymer materials. Despite numerous reports describing the chiral induction effect with single CPL, the synergistic or competitive effect between two types of CPL—i.e., circularly polarized ultraviolet light (CPUV) for triggering asymmetric polymerization while circularly polarized visible light (CPVL) only for accelerating helical chain propagation—is rarely reported. Here, this work demonstrates that the selective regulation on the asymmetric photopolymerization can be realized by the arbitrarily coupled irradiation with CPUV and CPVL, either constructively or destructively. In the former case, further chirality amplification can be achieved. Remarkably, for the latter case, the opposite handed CPVL can bias the polymer helicity during the chain propagation process and thereby overrule the helical preference inducted by CPUV. This work highlights the importance of chiral induction effect in helical chain propagation process and is highly valuable for deeper understanding of helical preference in CPL‐triggered asymmetric photopolymerization. [ABSTRACT FROM AUTHOR]

Polarization sensitive optical coherence tomography (PSOCT) makes use of the birefringence information of the sample to compensate for the lack of internal tissue-specific contrast in conventional optical coherence tomography (OCT). Circularly polarized light is always used as an incident beam in PSOCT, but it is difficult to have perfect in practice. The manual calibration method of circularly polarized light suffers from the problems of complicated calibration operation and lack of stability. This study proposes a simple method to enhance the imaging of PSOCT without altering the system. A numerical calibration of circularly polarized light can be implemented using the original system setup, ensuring that the system’s complexity remains unchanged. Enhancements in imaging quality can be achieved through an algorithmic analysis of the captured interference fringe data. This calibration is applied in the field map of interference data before being quadrature-assembled. Notably, the proposed approach achieves high sensitivity in PSOCT. The birefringence image shows a more obvious layered structure. Improvements in the signal-to-noise ratio (SNR) were demonstrated for chicken breast, pork, and beef imaging at about 20 dB.