Optically levitated micro- and nanoparticles are an ideal optomechanical platform for precision measurements, particularly enabling the detection of ultraweak forces. Nevertheless, quantum backaction and inherent instabilities induced by the trapping laser fundamentally restrict further improvements in force sensitivity and resolution. To circumvent these bottlenecks, we actively drive the levitated nanoparticle's mechanical motion in a phase-locked phonon laser mode and integrate a carrier-modulation measurement architecture to enhance force sensing capabilities. The stable and high-amplitude oscillation of the phonon laser allows for the robust trapping under 1 mW-level laser power, which in turn reduces the force noise to 4.0(3)*10^-22 N/Hz^1/2. Furthermore, by using phase-locked phonon laser, the measurement system achieves active stabilization and extended coherence time with the measured signal to 12,500 seconds, realizing a measurement resolution of 8(4)*10^-24 N with a sensitivity of 9.3(7)*10^-22 N/Hz^1/2 under a loaded force. These results establish the phonon laser as a low-noise, long-coherence-time, self-stabilizing platform for precision measurements, as well as in quantum and fundamental physics tests.

The Abbe diffraction limit, tied to the fundamental spatial bandwidth constraint imposed by any physical aperture, remains the primary barrier to achieving ultimate far-field optical resolution and precise light-matter interactions. However, current efforts to engineer structured light fields beyond this limit often come at the cost of massive sacrifices in energy efficiency. In this work, we mathematically complete the family of non-zero azimuthal-order Circular Prolate Spheroidal Wave Functions (CPSWFs), introducing them as a complete class of band-limited superoscillatory optical vortices carrying helical phase. Compared with classical Laguerre-Gaussian (LG) beams, we rigorously prove that these eigenmodes achieve the theoretical upper bound for extreme energy concentration under strict band-limited constraints. At the scale of light-matter interactions, this optimal concentration directly amplifies the intensity gradients and angular momentum densities that govern optical forces. This advantage translates directly into a 29.9

Phase singularities, manifesting as null intensity in optical speckle patterns, fundamentally constrain the uniformity of holographic reconstruction. A comprehensive understanding of their intrinsic physical properties is thus critical for advancing coherent optical systems, especially in the pursuit of speckle-free holography. Using a singularity-tracking methodology, we numerically investigate the evolution of these singularities as they propagate from holographic planes into free space. Our findings reveal two primary morphological classes of singularity trajectories-closed loops and linear paths-both exhibiting identical fractal characteristics. The topology invariance observed across these trajectories provides a robust framework for achieving high-uniformity speckle-free holography, either by eliminating singularities at the initial phase plane or by guiding them outside the target pattern. Notably, the fractal dimension of the trajectories ranges from 1.0 to 1.6 and demonstrates a negative correlation with the F-number of the hologram, exemplifying an optical analogy to a biased Brownian random walk under an attractive potential. This work offers novel statistical and topological insights into holographic speckle fields, paving the way for speckle-less reconstruction using highly coherent light.

It is intractable to perform information processing and computation on single ultrafast optical pulses, within picoseconds or even femtoseconds. Here, we experimentally demonstrate an optical spatiotemporal differentiator, a mirror-symmetry-breaking dielectric metagrating, which performs analog computations of both spatial and temporal differentiations on single ultrafast optical wavepackets. The spatiotemporal differentiator is designed with a transfer function with linear dependence on spatial wavevector and temporal frequency and fabricated by using a double-exposure E-beam lithography process. We achieve the first-order spatiotemporal differentiation with experimental resolutions of approximately 14 μm (in space) and 260 fs (in time). Furthermore, we report a parabolic relationship between the transverse velocity of a front-tilted photonic wavepacket and the normalized intensity of its first-order spatiotemporal-differentiation wavepacket. This relationship allows direct measurement of the transverse velocity using only the normalized intensity, fundamentally simplifying velocity detection. These capabilities of optical spatiotemporal computation endow emerging space-time optics with fundamental computation blocks.

Optical Stokes skyrmions have garnered extensive interest due to their intrinsic topological robustness and potential in informatics. However, most research remains confined to paraxial, low-numerical-aperture (low-NA) regimes, where their large transverse dimensions restrict broader applications. Under high-NA focusing, the polarization texture typically degrades or transforms abruptly as the beam traverses the focal region, hindering topology-preserving transport. In this work, a strategy is proposed to generate a skyrmion needle field that maintains both subdiffraction confinement and non-diffractive propagation under high-NA conditions, thus preserving their topological characteristics. Leveraging the polarization invariance of conventional optical needles, the Stokes skyrmion needle is realized using a single plasmonic metalens, which is designed to function as both a polarization filter and a super-resolving focusing element. Experimental and simulation results verify non-diffractive propagation over an extended depth of focus (up to 5), while the Stokes-vector texture is retained at subdiffraction scales throughout propagation. This skyrmion needle not only addresses previous propagation constraints but also opens new avenues for diffraction-unlimited information transport. Such skyrmion needles exhibit substantial potential in fields including light-matter interaction, optical metrology, and informatics.

Solid-state spins have emerged as one of the most promising platforms for quantum sensing and information processing. A high level of integration and miniaturization of quantum devices is required for practical and scalable applications. This limits the flexibility of spin manipulation and detection. In this work, we demonstrate the spatially selective manipulation of spin defects in diamond with a compact device. A tapered fiber-Ag nanowire-electrodes hybrid structure is fabricated to transmit an optical and electrical driving field. The polarization-dependent mode distribution is analyzed and subsequently utilized to optically excite spin defects. Combined with microwave pumping through the same device, we demonstrate the selective manipulation of spin defects at different positions without changing the physical architecture of the device. Our work provides a new scheme for developing integrated quantum sensors with high flexibility.

The negatively charged nitrogen-vacancy (NV) center in diamond exhibits several remarkable properties, which make it widely used in magnetic field sensing. In this paper, we present a miniaturized fiber-integrated chip-scale diamond magnetometer. The diamond sensor utilizes an optical fiber for side excitation to enhance fluorescence collection efficiency and subsequently integrates a microwave antenna and photodiodes on-chip. By coating the metal oxide dielectric film on the diamond surface, the green pump light can be filtered out. The implementation of the Ramsey sequence enhances sensitivity while suppressing microwave crosstalk in photovoltaic devices. The volume of the final sensing area is less than 6 mm3, and the magnetic field detection root sensitivity of 150 nT/ Hz is achieved. This sensor supports various practical applications, including microwave probing, energy monitoring, power systems, and non-destructive testing, while enabling a millimeter-scale standoff distance from the sensing region.

Nanoscale quantum sensing with solid-state spins enables high-spatial-resolution detection of microscopic physical phenomena, benefiting from their surface proximity, atomic-scale dimensions and optical addressability. The miniaturization of such sensing platforms is critical for broadening the applications. High-resolution optical imaging of solid-state spins typically requires bulky multi-lens objectives. Here, we report a single dielectric ultraflat metalens capable of both exciting and collecting fluorescence from spin defects. The high spatial resolution, comparable with traditional objective, is demonstrated through the optical imaging of spin defects in diamond. The nanoscale electromagnetic field sensing with spin defects in constrained space is subsequently realized, due to the high numerical aperture and small size of the metalens. Our work provides a platform for developing integrated nanoscale quantum sensing devices. The results will promote the compatibility of solid-state spin quantum sensor in various practical environment.

Magnetometers based on nitrogen-vacancy (NV) centers in diamonds have been widely studied. With the use of purified diamond and magnetic flux concentrators (MFCs), the sensitivity of magnetic field measurement has been improved to the subpico-tesla level. However, diamond magnetometers face the challenge of achieving high sensing performance after integration. Here, we demonstrate an integrated fiber-coupled diamond magnetometer based on an MFC with both high sensitivity and a wide dynamic range. We sandwiched a nitrogen-doped diamond film of [111] crystal orientation between the two MFCs. With the polarization direction of the pump laser perpendicular to the NV center axis, the signal-to-noise ratio and its linearity with the magnetic field are enhanced. We demonstrate a sensitivity of 50 $${{\rm{pT}}}/\sqrt{{{\rm{Hz}}}}$$@0.01 Hz and 390(172) $${{\rm{fT}}}/\sqrt{{{\rm{Hz}}}}$$@ > 3 Hz while with a detection range of about 4 times the Earth’s magnetic field. This work demonstrates the feasibility of portable, highly sensitive diamond magnetometers that maintain a large dynamic range in various natural environments. Diamond magnetometers leveraging nitrogen-vacancy centers offer precise magnetic field measurements but struggle with integration and miniaturization. Here, the authors present an integrated fiber-coupled diamond magnetometer using magnetic flux concentrators, achieving 50 $${{\rm{pT}}}/\sqrt{{{\rm{Hz}}}}$$ sensitivity and a wide dynamic range, paving the way for portable, high-performance sensing in diverse environments.

Exponential growth in global data traffic demands ever-increasing transmission rates–a pursuit fundamentally constrained by the physical limitations of digital-to-analog converters (DACs). Existing strategies to overcome this bottleneck, such as multi-DAC arrays and optical time-division multiplexing, inevitably introduce system complexity and coordination overhead. Here we demonstrate an all-optical spatiotemporal transmitter that generates controllable high-repetition information-carrying femtosecond pulses at the focus of a phase-modulated planar diffractive lens (PDL) through optical-path-induced spatial-to-temporal conversion. Each pulse serves as an information bit, encoding binary data via on-axis focal intensity states corresponding to '0' and '1', achieved by switching between topological and constant phase modulations. High experimental orthogonality between arbitrary bits enables nearly error-free transmission of 15X15-pixel grayscale (8-bit coding) and colour (9-bit coding) images at a record-high single-channel rate of approximately 3 terabits per second (Tbit/s). Free from electronic and coordination bottlenecks, this all-optical transmitter establishes a scalable high-speed single-channel pathway toward ultrahigh-capacity optical communication.

Optical tweezers offer precise, non-contact control, but operate in a limited force regime and impose strict requirements on the characteristics of the targets as well as the environmental conditions1-4. Millimetre-scale mechanical tweezers can offer higher gripping force but are not suitable for precise manipulations5-11. Integrating microgrippers directly at the optical fibres provides a new approach for precise micromanipulation. However, existing fibre-integrated tweezers still face challenges in achieving high-performance manipulation of micro-objects (for example, single cells) within narrow spaces, mainly due to simplified architectures, constrained designs and millimetre-scale footprints12-14. Here we report a three-dimensional (3D) optical fibre gripper (OFG), which is fabricated by two-step, two-photon polymerization. The OFG consists of rigid photoresist microclaws and soft thermoresponsive hydrogel muscle doped with silver nanoparticles, and its size is only 38 × 38 × 61 μm3. The OFG exhibits a force-to-mass ratio of about 340 μN mg-1, outperforming previously reported fibre-integrated tweezers by one to two orders of magnitude. The OFG can manipulate opaque particles, irregular micromechanical components and diverse single-cell types. We further demonstrated its potential in 3D microassembly of complex microdevices (bearings, shafts and gearboxes) and biomimetic sampling in the narrow environment (<300 μm). These results position the OFG as a compact fibre-tip manipulator for 3D micromanipulation, offering reversible and tunable gripping in an intermediate force regime between optical field trapping and millimetre-scale mechanical tweezers.

The room temperature manipulation of solid-state spins provides an opportunity to develop quantum applications under ambient conditions. Local electromagnetic fields, that usually produced by current in micro/nanoscale metal wires, have been employed for the coherent driving and addressing of spin qubit. However, the fixed distribution limits the spatial selectivity and efficiency of qubit manipulation, which is of central importance in a scaled-up quantum system. Here, we report a solution by demonstrating a reconfigurable current with arbitrary shape to engineer microwave and DC magnetic field at microscale. A "photothermal doping" method was proposed to optically control local insulator-to-metal transition in vanadium dioxide. It generates a conducting filament with adjustable position, direction, and width. Universal manipulation and selective addressing of spins at arbitrary sites are realized, by freely changing the filament and electromagnetic field on demand. Our work paves the way for developing quantum devices with large-scale spin qubits.

Anderson transition in quasiperiodic potentials and the associated mobility edges have been a central focus in quantum simulation across multidisciplinary physical platforms. While these transitions have been experimentally observed in ultracold atoms, acoustic systems, optical waveguides, and superconducting junctions, their interplay between quasiperiodic potential and long-range hopping remains unexplored experimentally. In this work, we report the observation of localization-delocalization transition induced by the hopping between the next-nearest neighboring sites using quasiperiodic photonic waveguides. Our findings demonstrate that increasing the next-nearest hopping strength induces a reentrant phase transition, where the system transitions from an initially extended phase into a localized phase before eventually returning to an extended phase. This remarkable interplay between hopping and quasiperiodic potential in the lattice models provides crucial insights into the mechanism of Anderson transition. Furthermore, our numerical simulation reveals that this phase transition exhibits a critical exponent of ν≃ 1/3, which is experimentally observable for system sizes L∼10^3 - 10^4. These results establish a framework for direct observation of the Anderson transition and precise determination of its critical exponents, which can significantly advance our understanding of localization physics in quasiperiodic systems.

Nonlinear magnonics has emerged as a prominent area of research, with a particular focus on on-chip Kerr nonlinearity. This effect is valuable both for its potential to manipulate magnon states and for its role in addressing the scalability challenges that magnonic devices face. In this Letter, we experimentally investigate a Kerr nonlinear magnomechanical system in a yttrium iron garnet thin-film device that supports magnon resonance coupled with multiple high-overtone bulk acoustic wave resonance modes. Notably, the enhanced Kerr nonlinearity resulting from the small mode volume enables clear bistability in the magnon mode at low excitation power. Additionally, we demonstrate the excitation of a magnon-phonon hybrid frequency comb using a single microwave tone and illustrate Kerr-induced synchronization of the frequency comb through externally injected reference microwaves, achieving over 130 comb teeth. Our findings provide a robust platform for the exploration of nonlinear magnonics and represent an advance in the development of on-chip frequency combs.

Rock magnetic microscopy (RMM) has emerged as an advanced methodology for imaging the magnetization distribution of geological thin sections under ambient conditions, providing precise information with high spatial resolution and high magnetic field sensitivity; however, several factors-including the large size and complexity of sensors, their low magnetic field sensitivity and small field of view, and the need for cryogenic conditions-have impeded the widespread adoption of current RMM setups. Here, we present a room-temperature, fiber-coupling, scanning scheme for RMM based on the negatively charged nitrogen-vacancy (NV) centers in diamond. A 200 x 200 x 50 mu m3 diamond chip is glued to a multimode fiber ferrule for scanning imaging of the magnetic field. To ensure the precision of the magnetic field measurements, the diamond surface is coated with a reflective gold film. A spatial resolution of 180 mu m and a magnetic field sensitivity of 52 nT/Hz1/2 in the near-dc frequency range below 10 Hz are achieved. This performance corresponds to a sensitivity of 10-12 A m2/Hz1/2 for magnetic moment measurements, approaching that of the superconducting rock magnetometer. The stray magnetic field distribution on a banded iron formation thin section is successfully scanned, revealing the inhomogeneous distribution of magnetization within the iron-rich bands. This study demonstrates the potential to extend the application scope of NV magnetometry in the frontiers of high-resolution geological research.

Quantum-correlated photon pairs are crucial resources for modern quantum information science. Similarly, the reliable generation of nonclassical phonon pairs is vital for advancing engineerable solid-state quantum devices and hybrid quantum networks based on phonons. Here, we present a novel approach to generate quantum-correlated phonon pairs in a suspended silicon microstructure initialized in its motional ground state. By simultaneously implementing red- and blue-detuned laser pulses, equivalent high-order optomechanical nonlinearity–specifically, an effective optomechanical four-wave mixing process–is achieved for generating a nonclassical phonon pair, which is then read out via a subsequent red-detuned pulse. We demonstrate the nonclassical nature of the generated phonon pair through the violation of the Cauchy-Schwarz inequality. Our experimentally observed phonon pair violates the classical bound by more than 5 standard deviations and maintains a decoherence time of 132 ns. This work reveals novel quantum manipulation of phonon states enabled by equivalent high-order optomechanical nonlinearity within a pulse scheme and provides a valuable quantum resource for mechanical quantum computing.