Conductive hydrogels are gaining significant attention for their potential in bioelectronic applications. Among these materials, poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) emerges as a promising candidate due to its intrinsic conductivity, flexibility, and biocompatibility. Recently, laser‐induced phase separation (LIPS) offers a tunable approach for modifying PEDOT:PSS, significantly enhancing its electrical conductivity, wet stability, and electrochemical stability. This technique also allows for high‐spatial‐resolution patterning, rendering it suitable for fabricating on‐demand bioelectronic interfaces. The excellent biocompatibility of the laser‐treated PEDOT:PSS further broadens its potential applications in soft bioelectronic devices. After revealing the LIPS mechanism of PEDOT:PSS and summarizing its key properties, this review offers an overview of its applications in neural signal recording, stimulation, and conduction block. This review establishes a critical connection among the mechanism, properties, and applications of LIPS, thereby paving the way for future research toward advanced bioelectronic applications and beyond.

In recent years, gigahertz (GHz)‐burst‐mode femtosecond lasers have revolutionized laser processing by significantly improving processing efficiency and quality. However, the underlying mechanisms are still unclear and experimentally optimizing the processing parameters is difficult due to their huge number. This study implements a theoretical approach based on simulations to investigate the underlying mechanisms of the Cu ablation efficiency enhancement by GHz‐burst mode. The simulation results obtained using a two‐temperature model suggest that the ablation efficiency is improved due to the interaction of subsequent intra‐pulses in a GHz burst with Cu melted by the preceding intra‐pulses. It is demonstrated that for GHz‐burst mode, a 515 nm wavelength achieves higher Cu ablation performance than when using the infrared wavelength and demonstrates 2.8 times higher ablation efficiency than the single‐pulse mode. The simulation results well agree with the experimental results. The approach used here represents a major advance not only in understanding the underlying mechanisms but also in determining the optimal processing conditions for practical applications.

All-Dielectric Metasurfaces Confinement of light within nanostructures of increasingly smaller sizes has resulted in ever more precise control of light-matter interactions. In article number 2400223, Taisuke Ohta and co-workers demonstrate near-field imaging of volume-type photonic resonances within a dielectric metasurface using photoelectron emission microscopy. This imaging approach, utilizing far-field excitation and sub-optical wavelength spatial resolution, offers a new avenue for examining light–matter interactions within dielectric nanophotonic systems.

Topological insulators (TIs) have unique topologically protected conducting surface and insulating bulk states, which provide a novel platform for plasmonic excitation and related nanoscale functional devices. Exploring plasmon‐enhanced interactions between light and atomic‐layered semiconductors in TI nanostructures is particularly significant for optoelectronic applications of TIs. Herein, the Sb2Te3 TI nanotips are fabricated by using focused ion beam lithography technique and the plasmonic hot spot behaviors are investigated on the TI nanotips. The numerical simulation shows that there exists a distinct reinforcement of light field on the Sb2Te3 TI nanotips, which stems from the TI‐based plasmonic hot spot effect. Moreover, the obvious enhancement of photoluminescence (PL) emission from a molybdenum disulfide (MoS2) monolayer integrated onto the Sb2Te3 TI nanotips is experimentally observed. The PL intensity of MoS2 layer on the Sb2Te3 nanotips can be effectively improved by about five‐fold due to the plasmonic hot spot‐induced field reinforcement when compared with that of MoS2 without the Sb2Te3 nanotips. These results will open a new avenue for optoelectronic applications of TIs, especially in nanoscale enhanced PL emission.

Whispering gallery mode (WGM) microcavities, which have been extensively studied for their ultrahigh Q factors and small mode volumes, are exceptional platforms for achieving ultralow‐threshold microlasers and functional resonators. However, the rotational symmetry of these structures traps light inside, resulting in an isotropic output and limiting their use in photonics. Special structural modifications are required to achieve a unidirectional light output in WGM cavity lasers. This study introduces and experimentally validates a novel method for achieving unidirectional light propagation in lasing microrings. Spatial symmetry is broken by integrating tilted azimuthal gratings on the inner wall of the microring. Consequently, clockwise and counterclockwise propagating WGMs exhibit distinct propagation losses and backscattering coefficients depending on the tilt angle of the grating, thereby enabling a controllable direction. This advancement paves the way for enhanced applications in integrated photonics such as unidirectional light sources and orbital angular momentum emitters, thereby expanding the functional capabilities of WGM microcavities.

Microfabrication using nano‐ to micron‐sized building blocks holds a great potential for applications in next‐generation electronics, optoelectronics, and advanced materials. However, traditional methods like chemical vapor deposition and molecular beam epitaxy require highly controlled environments and specialized equipment, limiting scalability and precision. To address these challenges, a single‐laser platform is presented for selective tweezing and immobilization of colloids (STIC) that integrates particle manipulation, assembly, and stabilization in one system. STIC utilizes a femtosecond laser at ultra‐low power for precise, contact‐free optical manipulation of colloids without material damage. At higher power, the same laser enables two‐photon polymerization (TPP) to immobilize colloids securely in their intended positions. Using STIC, the assembly of 3D structures from dielectric beads to patterned arrangements of transition metal dichalcogenides (TMDs e.g., MoS2) is demonstrated. Also a TPP‐fabricated handle as an intermediate support is incorporated which significantly enhances the optical tweezing efficiency of TMDs. The single‐laser design eliminates the need for dual‐laser systems, simplifying optical alignment, reducing heat damage, and improving efficiency. Additionally, it is shown that STIC supports direct multiphoton imaging for in situ inspection during fabrication. This work establishes a versatile, scalable optical platform for high‐precision microstructure fabrication, offering a pathway to overcome current limitations in micro‐ and nanomanufacturing.

Atmospheric turbulence constitutes a fundamental limiting factor in astronomical observation systems and laser communication architectures. During atmospheric propagation of optical beams, dynamically evolving wavefront aberrations are inevitably induced, rendering precise turbulence characterization and mitigation critical for optimizing operational performance of terrestrial telescopes and satellite‐ground optical links. Adaptive optics (AO) represents a sophisticated methodology for optical enhancement through real‐time wavefront measurement and adaptive compensation of medium‐induced phase distortions. Recent years have witnessed substantial advancements in AO technology, driven by synergistic progress in fundamental theories, optoelectronic devices, and computational algorithms. Furthermore, artificial intelligence‐driven turbulence processing frameworks leveraging deep neural networks have emerged as a prominent research frontier, demonstrating remarkable potential in intelligent wavefront sensing and nonlinear compensation. This work presents a systematic review of atmospheric turbulence fundamentals, including theoretical formulations and AO‐based mitigation strategies. Particular emphasis is placed on deep learning‐enabled intelligent correction paradigms, while critical analysis is provided regarding prospective research trajectories and implementation challenges.

Mode extraction is the inverse process of the double‐beam superposition principle in classical optics. While polarization mode extraction has been successfully demonstrated using an m‐order vector vortex beam, amplitude mode extraction remains a significant challenge due to the complex intertwinement of inherent amplitude modes. To address this challenge, a method is developed to extract arbitrary amplitude modes of a light beam in both the real and imaginary domains. By introducing competition between amplitude modes in these domains, the desired amplitude modes within a light beam can be selectively extracted in the focal region of an objective lens using an optical pen. This work demonstrates the principle of amplitude mode extraction, thereby potentially paving the way for multidimensional manipulation of light fields.

The key issue for a wide application of solar energy is the possibility to establish an innovative photovoltaic technology that allows a more efficient energy conversion. In this direction, the use of additional layers in the well‐established silicon‐based modules represents a challenging strategy. In this context, the present work is devoted to the optimization of a downshifting (DS) system made of the NaGdF4 matrix in the form of thin film as a host material for the europium‐luminescent ions. The Eu‐doped NaGdF4 system is fabricated through a sol–gel approach starting from a mixture of Na(hfa)•tetraglyme, Gd(hfa)3•diglyme, and Eu(hfa)3•diglyme in ethanol solution. The operative parameters are finely tuned to pursue the formation of compact and polycrystalline films. Particularly, the annealing treatment, the nature of the substrate, and the doping ion percentage are the key parameters for the reproducible and selective formation of NaGdF4 in the form of the beta (hexagonal) crystal structure with promising luminescent properties. Morphological, structural, and compositional features are deeply studied through field‐emission scanning electron microscopy, X‐ray diffraction analysis, and energy‐dispersive X‐ray analysis, respectively. The luminescence investigations confirm the properties of the Eu‐doped NaGdF4 as DS system.

Telecom band photonic quantum states generated from atomic systems are critical quantum resources for long‐distance and scalable quantum communication networks. Here, the beat phenomenon in the autocorrelation function of the telecom‐wavelength photon due to the velocity‐selective classes of the atoms in a Doppler‐broadened atomic ensemble of the cascade‐type 5S1/2–5P3/2–4D5/2 transition of 87Rb is reported. Although the signal (1529 nm) and idler (780 nm) photons are emitted from a single‐atomic ensemble, the autocorrelation functions of the signal and idler photons exhibit significantly different features, with temporal widths of 7 and 0.13 ns, respectively. Furthermore, the biphoton spectral waveform of the telecom band photon pair is measured using a stimulated emission method. The biphoton waveforms of the telecom‐wavelength biphoton source demonstrate good agreement with the magnitude of the Fourier components of the measured biphoton temporal and spectral waveforms.