Active beam steering and energy distribution have important applications for terahertz (THz) communication, radar, and imaging. However, the spin-conjugated mirror symmetry of a passive Pancharatnam–Berry (PB) metasurface limits the active energy distribution. Here, we prepared a low dispersion, low loss, and high magneto-optical coefficient La:YIG single crystal, ±45∘ Faraday rotation angle that can

The pursuit of advanced fiber laser technologies has driven research toward unconventional manufacturing techniques. In this work, we present an erbium-doped fiber laser made using powder-based additive manufacturing. An Er3+/Al3+ co-doped silica glass rod was printed using laser powder deposition and then used as the core material in a fiber preform. The fiber drawn from the preform exhibited the

Free-space optics allows for design freedom and control, but miniaturization and manufacturability are limited. Here, we present a method for manufacturing complex miniaturized free-space optical systems that combines contactless femtosecond laser-activated alignment with femtosecond laser 3D manufacturing of a substrate incorporating optomechanical elements. Specifically, we demonstrate a palm-sized

The design of wavefront-shaping devices is conventionally approached using real-frequency modeling. However, since these devices interact with light through radiative channels, they are by default non-Hermitian objects having complex eigenvalues (poles and zeros) that are marked by phase singularities in a complex frequency plane. Here, by using temporal coupled mode theory, we derive analytical expressions

Antiresonant hollow-core fibers (AR-HCFs) have opened up exciting possibilities for high-energy and high-power laser delivery because of their exceptionally low nonlinearities and high damage thresholds. While these fiber designs offer great potential for handling kilowatt-class powers, it is crucial to investigate their performance at multi-kW power levels. Until now, transmission of narrow-linewidth

Speckle patterns are used in a broad range of applications including microscopy, imaging, and light–matter interactions. Tailoring speckles’ statistics can dramatically enhance their performance in applications. We present an experimental technique for customizing the spatio-spectral speckled intensity statistics of optical pulses at the output of a complex medium (a disordered multimode fiber) by

Visible, high-coherence optical sources are important to a wide range of applications spanning spectroscopy to precision timing. Integration of these sources on a semiconductor chip is a necessary step if the systems that use these devices are to be made compact, portable, and low power. Here, by self-injection-locking a 1560 nm distributed feedback semiconductor laser to a high-Q silicon-nitride resonator

Ptychographic coherent diffractive imaging enables diffraction-limited imaging of nanoscale structures at extreme ultraviolet and x-ray wavelengths, where high-quality image-forming optics are not available. However, its reliance on a set of diverse diffraction patterns makes it challenging to use ptychography to image highly periodic samples, limiting its application to defect inspection for electronic

We present a study of 3D electromagnetic field zeros, uncovering their remarkable characteristic features and propose a classifying framework. These are a special case of general dark spots in optical fields, which sculpt light’s spatial structure into matter-moving, information-rich vortices, escape the diffraction limit for single-molecule imaging, and can trap particles for nanoscale manipulation

Single-shot high-speed mapping photography is a powerful tool used for studying fast dynamics in diverse applications. Despite much recent progress, existing methods are still strained by the trade-off between sequence depth and light throughput, errors induced by parallax, limited imaging dimensionality, and the potential damage caused by pulsed illumination. To overcome these limitations, we explore

M. V. Berry’s work [J. Phys. A 43, 415302 (2010) [CrossRef] ] highlighted the correspondence between backflow in quantum mechanics and superoscillations in waves. Superoscillations refer to situations where the local oscillation of a superposition is faster than its fastest Fourier component. This concept has been used to experimentally demonstrate backflow in transverse linear momentum for optical

Photonic molecules—particular systems composed of coupled optical resonators—emulate the behavior of complex physical systems exhibiting discrete energy levels. In this work, we present a photonic molecule composed of two strongly coupled, mid-infrared ring quantum cascade lasers. We explore both experimentally and numerically the key features of the photonic molecule such as the energy level splitting

Methods for controlling the motion of single particles, optically levitated in vacuum, have developed rapidly in recent years. The technique of cold damping makes use of feedback-controlled, electrostatic forces to increase dissipation without introducing additional thermal fluctuations. This process has been instrumental in the ground-state cooling of individual electrically charged nanoparticles

Micro–electro–mechanical systems (MEMS)-based optical scanners play a vital role in the development of miniaturized optical imaging modalities. However, there is a longstanding challenge to balance the temporal resolution, field of view (FOV), and systematic fidelity. Here, we propose a double spiral scanning mechanism to enable high-frequency resonant scanning of MEMS scanners without sacrificing

Chip-scale integrated spectrometers have many prospective applications, such as in situ biochemical analysis, optical coherence tomography, and remote hyperspectral sensing. Most reported monolithically integrated spectrometers support spectral resolutions of 101−102pm with 102−103 wavelength channels. In this work, we propose and demonstrate a scalable integrated spectrometer that achieves ultrahigh

Optical measurements that can achieve the fundamental quantum limits have the potential to improve the imaging of subdiffraction objects in important applications, including optical astronomy and fluorescence microscopy. Working towards the goal of implementing such quantum-inspired measurements for real applications, we experimentally demonstrate the localization of two incoherent optical point sources

Optical vortices—lines of zero intensity around which the field phase has a circulating or helical structure—have become important tools for many applications such as imaging, trapping, and communications. It has long been assumed, however, that there is an intrinsic conflict between optical vortices and partial coherence, in that a vortex is a deterministic phase structure, and a partially coherent

Optical phase measurement is critical for many applications, and traditional approaches often suffer from mechanical instability, temporal latency, and computational complexity. In this paper, we describe compact phase sensor arrays based on integrated photonics, which enable accurate and scalable reference-free phase sensing in a few measurement steps. This is achieved by connecting multiple two-port

The incredible phase sensitivity of Michelson interferometry has made it useful for a variety of metrology and sensing applications with the trade-off that it is also vulnerable to unwanted fluctuations in the sensing environment. Here, we demonstrate that Michelson interferometry using either Gaussian or space–time (ST) light sheets results in enhanced passive phase stability. Our experiments are

Semiconductor optical amplifiers (SOAs) are a fundamental building block for many photonic systems. However, their power inefficiency has been setting back operational cost reduction, circuit miniaturization, and the realization of more complex photonic functions such as large-scale switches and optical phased arrays. In this work, we demonstrate significant gain and efficiency enhancement using an

The need to observe objects that are smaller than the diffraction limit has led to the development of various superresolution techniques. However, most such techniques require active interaction with the sample, which may not be possible in multiple practical scenarios. The recently developed technique of Hermite–Gaussian imaging (HGI) achieves superresolution by passively observing the light coming

Wigner function tomography is indispensable for characterizing quantum states, but its commonly used version, balanced homodyne detection, suffers from several weaknesses. First, it requires efficient detection, which is critical for measuring fragile non-Gaussian states, especially bright ones. Second, it needs a local oscillator, tailored to match the spatiotemporal properties of the state under

Single-photon detectors with picosecond timing resolution have advanced rapidly in the past decade. This has spurred progress in time-correlated single-photon counting applications, from quantum optics to life sciences and remote sensing. A variety of advanced optoelectronic device architectures offer not only high-performance single-pixel devices but also the ability to scale up to detector arrays

In this work, we observe natural exceptional points in the excitation spectrum of an exciton–polariton system by optically tuning the light–matter interactions. The observed exceptional points do not require any spatial or polarization degrees of freedom and result solely from the transition from weak to strong light–matter coupling. It was demonstrated that they do not coincide with the threshold

Resonant excitation is an essential tool in the development of semiconductor quantum dots (QDs) for quantum information processing. One central challenge is to enable transparent access to the QD signal without post-selection information loss. A viable path is through cavity enhancement, which has successfully lifted the resonantly scattered field strength over the laser background under weak excitation

Laser gyros are powerful tools used to test the predictions of the general theory of relativity. The precision of a measurement of the rotation rate with a laser gyro is limited by the frequency noise of the beat between two counterpropagating modes of a ring laser. The frequency noise of a single mode of a laser is limited by quantum mechanical constraints because it is related to the maximum precision

A two-mode squeezed microresonator-based frequency comb is demonstrated with CMOS-compatible silicon nitride integrated photonic circuits. Seventy quantum modes, in a span of 1.3 THz, are generated in an integrated Kerr microresonator at telecommunication wavelengths.

While most lasers are linearly polarized, circularly polarized laser sources are crucial components for many optical applications such as biosensing, quantum technologies, and AR/VR. However, conventional methods for generating chiral light have limitations in device miniaturization. Vertical-cavity surface-emitting lasers (VCSELs), with their small footprint and surface emission feature, can be integrated

When viewed under coherent illumination, scattering materials such as tissue exhibit highly varying speckle patterns. Despite their noise-like appearance, the temporal and spatial variations of these speckles, resulting from internal tissue dynamics and/or external perturbation of the illumination, carry strong statistical information that is highly valuable for tissue analysis. The full practical

Use of artificial intelligence for tasks such as image classification and speech recognition has started to form an integral part of our lives. Facilitation of such tasks requires processing a huge amount of data, at times in real time, which has resulted in a computation bottleneck. Photonic cores promise ultra-fast convolutional processing by employing broadband optical links to perform parallelized

The penetrating power of x rays underpins important applications such as medical radiography. However, this same attribute makes it challenging to achieve flexible on-demand patterning of x-ray beams. One possible path to this goal is “ghost projection,” a method that may be viewed as a reversed form of classical ghost imaging. This technique employs multiple exposures of a single illuminated non-configurable

The colors of objects originate from reflection of light in certain directions and absorption of undesired light, producing substantial heating. Extensive efforts are expended to cool colorful objects to reduce their energy consumption. However, a strategy to cool colorful objects below ambient temperature while fully preserving their excellent color properties with high saturation and large viewing

The possibility of obtaining a three-dimensional (3D) representation of a single object with sub-µm resolution is crucial in many fields, from material science to clinical diagnostics. This is typically achieved through tomography, which combines multiple 2D images of the same object captured with different orientations. However, this serial imaging method prevents single-shot acquisition in imaging

The discrete multi-longitudinal mode structure and temporal periodic fluctuation are the intrinsic features of conventional lasers. However, longitudinal mode spacing limits the maximum resolution in high-resolution laser sensing systems. In addition, temporal periodic fluctuation reduces the security of secure communication and deteriorates the randomness in fast physical random bit generation. Therefore

Attosecond metrology with linearly polarized light pulses is the basis of a highly successful research area. An even broader impact can be expected from a generalized metrology that covers two-dimensional polarization states, enabling notably the study of chiroptical phenomena on the electronic time scale. Here, we introduce and demonstrate a comprehensive approach to the generation and complete characterization

Primary methods for generating short pulses in lasers require intracavity elements or physical mechanisms for modulation or the saturable absorption of radiation. This often complicates laser design and limits capabilities, particularly beyond single-wavelength operation. We propose and explore a method for the synchronous generation of bicolor, high-repetition-rate pulses that combines stimulated

A benefit of random illumination microscopy (RIM) is that it improves the resolution and linearity of the brightness of structured illumination microscopy using minimally controlled speckled illumination. Here, we implemented RIM in the total internal reflection fluorescence (TIRF) configuration for imaging biological processes close to the coverslip surface. Using standard TIRF objectives, we separated

An uncooled detector has reached the thermodynamic temperature fluctuation limit, such that 98% of its total noise consisted of phonon and photon fluctuations of the detector body. The device has performed with a detectivity of 3.8×109cm√Hz/W , which is the highest reported for any room temperature device operating in the long-wave infrared (λ∼8−12µm ). The device has shown a noise-equivalent temperature

Three-dimensional inspection of nanostructures such as integrated circuits is important for security and reliability assurance. Two scanning operations are required: ptychographic to recover the complex transmissivity of the specimen, and rotation of the specimen to acquire multiple projections covering the 3D spatial frequency domain. Two types of rotational scanning are possible: tomographic and

Recent developments in chip-based frequency-comb technology demonstrate that comb devices can be implemented in applications where photonic integration and power efficiency are required. The large number of equally spaced comb lines that are generated make combs ideal for use in communication systems, where each line can serve as an optical carrier to allow for massively parallel wavelength-division

Quantum light is described not only by a quantum state but also by the shape of the electromagnetic modes on which the state is defined. Optical precision measurements often estimate a “mode parameter” that determines properties such as frequency, temporal shape, and the spatial distribution of the light field. By deriving quantum precision limits, we establish the fundamental bounds for mode parameter

We demonstrate a nano-buried-heterostructure photonic crystal laser exhibiting an ultralow threshold of 730 nA at telecom wavelengths. This breakthrough was achieved by reducing the doping-induced losses of the laser cavity, enabling the efficient miniaturization of the active region. The laser can be directly modulated at 3 GHz at an energy cost of 1 fJ/bit, and a comparison to longer lasers is given

Disordered stealthy hyperuniform dielectric composites exhibit novel electromagnetic wave transport properties in two and three dimensions. Here, we carry out the first study of the electromagnetic properties of one-dimensional 1D) disordered stealthy hyperuniform layered media. From an exact nonlocal theory, we derive an approximation formula for the effective dynamic dielectric constant tensor εe(kq

Integrated photonics provides a powerful approach for developing compact, stable, and scalable architectures for the generation, manipulation, and detection of quantum states of light. To this end, several material platforms are being developed in parallel, each providing its specific assets, and hybridization techniques to combine their strengths are available. This review focuses on AlGaAs, a III–V

Accurately yet efficiently simulating off-axis diffraction is vital to design large-scale computational optics, but existing rigid sampling and modeling schemes fail to address this. Herein, we establish a universal least-sampling angular spectrum method that enables efficient off-axis diffraction modeling with high accuracy. Specifically, by employing the Fourier transform’s shifting property to convert

We present a deep learning (DL) framework, termed few-photon fluorescence lifetime imaging (FPFLI), for fast analysis of fluorescence lifetime imaging (FLIM) data under highly low-light conditions with only a few photons per pixel. FPFLI breaks the conventional pixel-wise lifetime analysis paradigm and fully exploits the spatial correlation and intensity information of fluorescence lifetime images

Terahertz (THz) magnetoresistance effects have been extensively investigated and have shown promising results for applications in magnetic modulations of the amplitude of THz waves. However, THz magnetocapacitance in dielectric systems, which is essential for phase modulations of THz radiation, remains largely unexplored. Here, we study the THz response of a bulk single crystal of La0.875Sr0.125MnO3

Quantitative phase imaging provides a way to image transparent objects, such as biological cells, and measure their thickness. We report on a phase-imaging method that achieves twice the phase shift and approximately 1.7 times the spatial resolution of an equivalent spatially and temporally coherent classical quantitative phase-imaging system by using quantum interference between successive spontaneous

Refraction-based x-ray imaging can overcome the fundamental contrast limit of computed tomography (CT), particularly in soft tissue, but so far has been constrained to high-dose ex vivo applications or required highly coherent x-ray sources, such as synchrotrons. Here we demonstrate that grating interferometry (GI) is more dose efficient than conventional CT in imaging of human breast under close-to-clinical

The European X-ray Free Electron Laser facility produces extremely intense and short X-ray pulses. A diamond sensor proposed for non-invasive diagnostics of hard X-rays enables pulse-resolved beam position measurements within less than 1% uncertainty at 2.25MHz .

Optomechanical crystals (OMCs) are a promising and versatile platform for transduction between mechanical and optical fields. However, the release from the substrate used in conventional suspended OMCs also complicates manufacturing and severely reduces thermal anchoring. This may be improved by attaching the OMCs directly to the substrate. Previous work towards such clamped, i.e., non-suspended, OMCs

Comb-based optical arbitrary waveform measurement (OAWM) techniques can overcome the bandwidth limitations of conventional coherent detection schemes, thereby enabling ultra-broadband signal acquisition in a wide range of scientific and industrial applications. For efficient and robust implementation of such OAWM systems, miniaturization into chip-scale form factors is key. In this paper, we propose

Optoelectronic memory is attracting tremendous attention as an emerging strategy to emulate the human visual system. However, most devices to date focus on converting visual information in real time, rarely meeting the expectation of memorizing that information. Here, we report the discovery of a light-induced nonvolatile trapping effect that shows remarkable long-term storage of optical signals in

Lasers at ∼900nm have been of vital importance in various fields, including material processing, underwater communications, and strong-field physics. Although Nd3+ -doped materials have been employed for the ∼900nm laser, the ∼900nm emission is in strong competition with the often more dominating ∼1060nm emission, which strongly limits the output power and applications. This paper proposes a direct

Antiresonant, hollow-core optical fibers are currently challenging or even exceeding the loss performance of conventional solid-core fibers. Despite this progress, there are aspects of the guidance mechanism in these fibers that are still not understood. For example, a physical mechanism to explain why negative curvature of the core surround is correlated with low loss remains elusive. It is shown

X-ray microtomography is a nondestructive, three-dimensional inspection technique applied across a vast range of fields and disciplines, ranging from research to industrial, encompassing engineering, biology, and medical research. Phase-contrast imaging extends the domain of application of x-ray microtomography to classes of samples that exhibit weak attenuation, thus appearing with poor contrast in

Visible wavelengths of light control the quantum matter of atoms and molecules and are foundational for quantum technologies, including computers, sensors, and clocks. The development of visible integrated photonics opens the possibility for scalable circuits with complex functionalities, advancing both science and technology frontiers. We experimentally demonstrate an inverse design approach based

Chiral lasers with orbital angular momenta (OAM) are building blocks in developing high-dimensional integrated photonic devices. However, it remains demanding to arbitrarily manipulate the precise degree of chirality (DOC) and quantum numbers of OAM in microscale lasers. This study reports a strategy to generate OAM microlasers with tunable DOCs and large quantum numbers through a ring-structured Fabry–Perot

Light–matter interactions are often considered governed by the electric optical field only, leaving aside the magnetic component of light. However, the magnetic part plays a determining role in many optical processes, from light and chiral-matter interactions and photon-avalanching to forbidden photochemistry, making the manipulation of magnetic processes extremely relevant. Here, by creating a standing

The use of chip-based micro-resonator Kerr frequency combs in conjunction with dense wavelength-division multiplexing (DWDM) enables massively parallel intensity-modulated direct-detection data transmission with low energy consumption. Resonator-based modulators and filters used in such systems can limit the number of usable wavelength channels due to practical constraints on the maximum achievable