We propose a laser speckle contrast imaging method based on uniting spatiotemporal Fourier transform. First, the raw speckle images are entirely transformed to the spatiotemporal frequency domain with a three-dimensional (3D) fast

Aiming for suppressing side-mode and spectrum broadening, a slit beam-shaping method and super-Gaussian apodization processing for femtosecond laser point-by-point (PbP) inscription technology of fiber Bragg gratings (FBGs) are re

We experimentally transmit eight wavelength-division-multiplexing (WDM) channels, 16 quadratic-amplitude-modulation (QAM) signals at 32-GBaud, over 1000 km few mode fiber (FMF). In this experiment, we use WDM, mode division multip

A concept of divergence angle of light beams (DALB) is proposed to analyze the depth of field (DOF) of a 3D light-field display system. The mathematical model between DOF and DALB is established, and the conclusion that DOF and DA

Edge detection for low-contrast phase objects cannot be performed directly by the spatial difference of intensity distribution. In this work, an all-optical diffractive neural network (DPENet) based on the differential interferenc

Metalenses are essential components in terahertz imaging systems. However, without careful design, they show limited field of view and their practical applications are hindered. Here, a wide-angle metalens is proposed whose struct

We demonstrate a simultaneous transmission of time-frequency and data over a 160-km urban business network in Shanghai. The signals are transmitted through a cascaded optical link consisting of 48 km and 32 km, which are connected

A new electronic speckle pattern interferometry method is proposed to realize in situ deformation measurements. The feature of the method is the combination of a high-speed camera and multiple laser Doppler vibrometers (LDVs) for

Optical coherence tomography (OCT) allows a direct and precise measurement of laser welding depth by coaxially measuring the keyhole depth and can be used for process monitoring and control. When OCT measurement was taken during s

We propose an absolute distance measurement method that employs heterodyne and superheterodyne combined interferometers to achieve synchronous detection and demodulation of multiwavelengths. Coarse and fine synthetic wavelengths a

A flexible-grid 1×(2×3) mode- and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed, optimized, and demonstrated experimentally in this work. By carefully therm

Mode splitters that directly separate modes without changing their orders are highly promising to improve the flexibility of the mode-division multiplexing systems. In this paper, we design a high-performance mode splitter on the

Silicon waveguides typically exhibit optical anisotropy, which leads to polarization correlation and single-polarization operations. This consequently creates a demand for polarization-control devices. This paper introduces a CMOS

The dual-mode stabilization scheme has been demonstrated as an efficient way to stabilize laser frequency. In this study, we propose a novel dual-mode stabilization scheme that employs a sizable Fabry–Pérot cavity instead of the m

We present a study on a watt-level acousto-optically Q-switched Pr:YLF laser at three different repetition rates (10 kHz, 20 kHz, and 50 kHz) for the first time, to the best of our knowledge. The corresponding average output power

We present our efforts towards power scaling of Er:Lu2O3 lasers at 2.85 µm. By applying a dual-end diode-pumped resonator scheme, we achieve an output power of 14.1 W at an absorbed pump power of 59.7 W with a slope efficiency of

High accuracy and time resolution optical transfer delay (OTD) measurement is highly desired in many multi-path applications, such as optical true-time-delay-based array systems and distributed optical sensors. However, the time r

A sub-Nyquist radar receiver based on photonics-assisted compressed sensing is proposed. Cascaded dictionaries are applied to extract the delay and the Doppler frequency of the echo signals, which do not need to accumulate multipl

The stable long-distance transmission of radio-frequency (RF) signals holds significant importance from various aspects, including the comparison of optical frequency standards, remote monitoring and control, scientific research a

We propose a spatially chirped quasi-phase-matching (QPM) scheme that enables ultrabroadband second-harmonic-generation (SHG) by using a fan-out QPM grating to frequency-convert a spatially chirped fundamental wave. A “zero-disper

Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole distributions. Because of its special properties, the toroidal dipole is a research hotspo

Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability. Over

In this paper, we demonstrate nBn InAs/InAsSb type II superlattice (T2SL) photodetectors with AlAsSb as the barrier that targets mid-wavelength infrared (MWIR) detection. To improve operating temperature and suppress dark current,

The dynamics of water within a nanopool of a reverse micelle is heavily affected by the amphiphilic interface. In this work, the terahertz (THz) spectra of cyclohexane/Igepal/water nonionic reverse micelle mixture are measured by

The characteristics of plasmas play an important role in femtosecond laser filament-based applications. Spectroscopic analysis is used to experimentally investigate the plasma density and its temperature of the air filament under

Two-dimensional (2D) van der Waals materials have attracted tremendous attention due to their versatile physical properties and flexible manipulation approaches. Among the various types of van der Waals materials, α-In2Se3 is rema