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A random laser carrying the scattering information on a biological host is a promising tool for the characterization of biophysical properties. In this work, random lasing from label-free living cells is proposed to achieve rapid cytometry of apoptosis. Random lasing is achieved by adding biocompatible gain medium to a confocal dish containing cells under optically pumped conditions. The random lasing characteristics are distinct at different stages of cell apoptosis after drug treatment. By analyzing the power Fourier transform results of the random lasing spectra, the percentage of apoptotic cells could be distinguished within two seconds, which is more than an order of magnitude faster than traditional flow cytometry. These results provide a label-free approach for rapid cytometry of apoptosis, which is advantageous for further research of random lasers in the biological field.

An all-optical tunable whispering gallery mode (WGM) laser pumped by a laser diode is proposed. The laser is fabricated by filling a silica capillary with a light-emitting conjugated polymer solution. Based on the thermo-optic effect of the hydroxyl groups in the polymer and capillary, the effective refractive index of the WGM cavity changes by the auxiliary irradiation of the laser, and the wavelength of the WGM mode shifts correspondingly. The emission wavelength was continuously tuned over 13 nm with the irradiation power intensity changing from 0 to 22.41 W cm

Multiferroic materials have great potential in non-volatile devices for low-power and ultra-high density information storage, owing to their unique characteristic of coexisting ferroelectric and ferromagnetic orders. The effective manipulation of their intrinsic anisotropy makes it promising to control the multiple degrees of freedom of the storage "medium". Here, we have discovered intriguing electrical and magnetic anisotropies within the intralayer of CuCrP2S6, a promising van der Waals multiferroic material. The in-plane uniaxial anisotropies of the current rectifications, magnetic properties and magnon modes are demonstrated and manipulated by electric direction/polarity, temperature variation and magnetic field. More important, we have observed spin-flop transition corresponding to specific magnon modes, and it is well supported by theoretical calculations. Our work provides the first observation of electrical and magnetic anisotropies with same easy axis in van der Waals multiferroics, which will stimulate novel device applications of artificial bionic synapses, multi-terminal spintronic chips and magnetoelectric devices.

Light-emitting fabric can facilitate the innovation of wearable display applications. Electronic and luminescent textiles capable of communicating, sensing, and supplying energy have been achieved. However, a facile strategy for fabricating large-area flexible lasing textiles has not yet been reported. In this work, we propose a gravity-assisted rotatory drawing method for fabricating flexible lasing microfibers, which can be woven into multicolor lasing textiles. By regulating the doped dyes and solution viscosity, we achieve the mass manufacturing of lasing microfibers with different emission colors and modes and further weave them into full-color textiles with a wide color gamut, approximately 79.1% larger than that of standard RGB space. For application, we print nanoparticle patterns on the lasing textile and encode it with programmable lasing signal distribution, which can supply an anticounterfeiting label for efficient authentication. This work unifies the fabrication and application of lasing textiles, and we expect that this will provide a new platform for flexible lasing devices.

Chaotic cryptography as an important means for digital image encryption has become a great cryptographic project in the current information age. As a novel microcavity laser, a random laser (RL) has a natural advantage for a chaotic system, relying on its spectral randomness. Nevertheless, this encrypted image generally suffers from outline exposition when an unsuitable key from a single RL spectrum is employed. Herein, to realize reliable dual chaotic encryption, an internally integrated hybrid microcavity in random and whispering-gallery-mode (WGM) is reported. Within this coupled microcavity, the rhodamine-6G-doped inner-wall of the fiber serves as the gain medium and the optical cavities for WGM lasing; an RL mode is enabled by scattered particles and the gain medium (Rh6G). Interestingly, the smooth inner wall of the fiber with a high-quality (

A hybrid membrane is employed as a high-order plasmonic distributed feedback (DFB) cavity to reduce the lasing threshold of polymer lasers. The hybrid membrane consists of an anodic aluminum oxide (AAO) membrane, a 25 nm thick silver layer and a free-standing polymer membrane. The AAO membrane is fabricated by a low-cost, single chemical etching method. Then, a layer of silver with a thickness of 25 nm is sputtered on the surface of the AAO. Subsequently, a polymer membrane is directly attached to the silver-plated AAO membrane, forming an AAO/silver/polymer hybrid membrane. Under optical pumping conditions, low-threshold, three-order DFB lasing is observed. The proposed laser device exhibited a dual-threshold characteristic because of the evolution from amplified spontaneous emission to DFB lasing. And a significant shift from omnidirectional emission to directional emission lasing can be observed while the pump energy density is beyond the second threshold. Furthermore, the plasmonic enhancement sourced from silver corrugation reveals important improvement effects to the DFB lasing of AAO/silver/polymer hybrid membrane for decreasing threshold, narrowing full width at half maximum (FWHM), and an increasing Q factor. This work may promote the design and production of low-cost and large-area high-order plasmonic DFB polymer lasers.

Miniaturized lasing with dynamic manipulation is critical to the performance of compact and versatile photonic devices. However, it is still a challenge to manipulate the whispering gallery mode lasing modes dynamically. Here, we design the quasi-three-dimensional coupled cavity by a micromanipulation technique. The coupled cavity consists of two intersection polymer microfibers. The mode selection mechanism is demonstrated experimentally and theoretically in the coupled microfiber cavity. Dynamic manipulation from multiple modes to single-mode lasing is achieved by controlling the coupling strength, which can be quantitatively controlled by changing the coupling angle or the coupling distance. Our work provides a flexible alternative for the lasing mode modulation in the on-chip photonic integration.

Spintronics and molecular chemistry have achieved remarkable achievements separately. Their combination can apply the superiority of molecular diversity to intervene or manipulate the spin-related properties. It inevitably brings in a new type of functional devices with a molecular interface, which has become an emerging field in information storage and processing. Normally, spin polarization has to be realized by magnetic materials as manipulated by magnetic fields. Recently, chiral-induced spin selectivity (CISS) was discovered surprisingly that non-magnetic chiral molecules can generate spin polarization through their structural chirality. Here, the recent progress of integrating the strengths of molecular chemistry and spintronics is reviewed by introducing the experimental results, theoretical models, and device performances of the CISS effect. Compared to normal ferromagnetic metals, CISS originating from a chiral structure has great advantages of high spin polarization, excellent interface, simple preparation process, and low cost. It has the potential to obtain high efficiency of spin injection into metals and semiconductors, getting rid of magnetic fields and ferromagnetic electrodes. The physical mechanisms, unique advantages, and device performances of CISS are sequentially clarified, revealing important issues to current scientific research and industrial applications. This mini-review points out a key technology of information storage for future spintronic devices without magnetic components.

We present a hybrid cavity designed to manipulate lasing modes, consisting of a metal-dielectric core–shell hybrid microcavity fabricated using a simple brush-coating method. Single and multiple modes can be obtained in the proposed laser device by the trade-off between loss and gain. Moreover, we achieve electrically tunable whispering-gallery-mode lasing by employing the thermo-optic effect in the hybrid microcavity. The lasing peak of the modes can be electrically tuned by quantitative control of Joule heating. We measure a tuning rate of 15.3 pm/J for all the lasing peaks.

Organic phosphorescence, originating from triplet excitons, has potential for the development of new generation of organic optoelectronic materials. Herein, two heavy‐atom‐free room‐temperature phosphorescent (RTP) electron acceptors with inherent long lifetime triplet exctions are first reported. These two 3D‐fully conjugated rigid perylene imide (PDI) multimers, as the best nonfullerene wide‐bandgap electron acceptors, exhibit a significantly elevated T1 of ≈2.1 eV with a room‐temperature phosphorescent emission (τ = 66 µs) and a minimized singlet–triplet splitting as low as ≈0.13 eV. The huge spatial congestion between adjacent PDI skeleton endows them with significantly modified electronic characteristics of S1 and T1. This feature, plus with the fully‐conjugated rigid molecular configuration, balances the intersystem crossing rate and fluorescence/phosphorescence rates, and therefore, elevating E T1 to ≈2.1 from 1.2 eV for PDI monomer. Meanwhile, the highly delocalized feature enables the triplet charge‐transfer excitons at donor–acceptor interface effectively dissociate into free charges, endowing the RTP electron acceptor based organic solar cells (OSCs) with a high internal quantum efficiency of 84% and excellent charge collection capability of 94%. This study introduces an alternative strategy for designing PDI derivatives with high‐triplet state‐energy and provides revelatory insights into the fundamental electronic characteristics, photophysical mechanism, and photo‐to‐current generation pathway., The long‐lived excitons are of significance to alleviate the strong morphology‐ and thickness‐dependence of organic photovoltaic performance and therefore accelerating its industrialization process. Here, two room‐temperature phosphorescent electron acceptors with long‐lived triplet exctions and high‐energy level are investigated systematically for the first time. This work provides revelatory insights into their fundamental electronic characteristics, photophysical mechanism, and photo‐to‐current generation pathway.

The Mn3X (where X = Ga, Ge, Sn, etc.) compounds have appealing prospects for spintronic applications due to their various crystal structures and magnetic properties for the design of reliable high-density memories. However, controlled growth of high-quality Mn3X thin films remains challenging in material science. Here, we reported the controlled film growth of Heusler alloy Mn3Ge, which could crystallize in respective tetragonal and hexagonal structures. The tetragonal D022-type Mn3Ge film exhibits strong perpendicular ferromagnetic anisotropy, while the hexagonal D019-type Mn3Ge film indicates non-collinear triangular antiferromagnetic order. From our experimental observations of structure characterizations, magnetic properties, anomalous Hall effect, and magnetoresistance measurements, we realized the manipulation of spin orientations and topological features. Majority/minority spin polarized Fermi surface and density of states of both tetragonal and hexagonal Mn3Ge structures were investigated by density functional theory calculations. Our work not only opens up technology routes toward the development of Mn3X-based devices for applications in topological spintronics and spin-torque memories but also leads to engineer the physical properties for fundamental study.