This study introduced a differential polarization division multiplexing (DPDM) scheme for all-fiber high-accuracy spectral measurement. Launching two orthogonal linearly polarized light beams into multimode fibers, the DPDM elegan

This study investigates the application of miniature quantum references within small-scale optical atomic frequency standards, utilizing a diminutive 87Rb glass cell, dimensions of 6 mm × 6 mm × 6 mm, to establish a quantum freque

In this work, a 4H-SiC-based soft X-ray single photon detector with photon energy resolution capability is demonstrated. The 4H-SiC p-i-n detector with an 80-μm-thick epi-layer and low intrinsic doping exhibits a low leakage curre

Optical coherence tomography (OCT) offers a direct and precise measurement of keyhole depth in laser welding, facilitating its application for quality assurance and control. Nevertheless, in high-speed welding, the keyhole lags be

It is meaningful to develop a high-performance optic bending sensor characterized by effective direction judgment, compact length, and high sensitivity. In this Letter, a compact Mach–Zehnder interferometer (MZI) fiber sensor for

Accurately perceiving the multidimensional geometric information of complex equipment is crucial for improving product quality and production efficiency. We propose a multichannel time-domain wavelength division multiplexing frequ

Long-distance surface profiling requires a high level of vibration resistance. Here, we propose a heterodyne interferometry scheme that uses two acousto-optic modulators (AOMs) to achieve precise and high-speed heterodyne phase-sh

Considering practical unknown magnetic detection, fast magnetic field search and locking scheme is needed in atomic magnetometers. Here, based on the in-phase response of atomic polarization rotation, we provide an iterative searc

Coherent lidar (CL) addresses existing constraints in CL data products by enabling simultaneous observation of multiple meteorological parameters such as cloud height, extinction coefficient, aerosol concentration, and wind field

A novel Mach–Zehnder interferometer (MZI) sensor based on multiple supermode interferences that can be used for dual-parameter measurements of temperature and strain is proposed and demonstrated. The MZI is made by splicing a coup

A highly sensitive temperature sensor was developed using a thin-walled SiO2 hollow microrod resonator (SHMR) to excite Lorentz resonance and Fano resonance. The SHMR has a high Q factor (3.16 × 107) and concise resonance modes. M

This study proposes a method for real-time monitoring of lithium-ion battery (LiB) internal temperatures through the temperature response of an embedded fiber Bragg grating (FBG) sensor. This approach overcomes the limitations of

In this paper, we present a method to expedite multi-wavelength photoelasticity for efficient stress analysis. By modulating two slightly different-wavelength illumination beams and simultaneously capturing dark-field and bright-f

The metabolic process of chiral drugs plays a significant role in clinics and in research on drugs. Here, we experimentally demonstrate by all-optical means that the chiral molecules can be quickly discriminated and monitored with

In this study, an innovative technique is introduced to significantly enhance the sensitivity of electronic speckle pattern interferometry (ESPI) for the dynamic assessment of specular (mirrorlike) object deformations. By utilizin

In this work, we propose a method using frequency-modulated continuous-wave (FMCW) self-mixing interferometry (SMI) and all-phase fast Fourier transform (APFFT) for simultaneous measurement of speed and distance. APFFT offers supe

The development of hybrid optics/microwave communication systems puts forward a new requirement for beam splitters to efficiently transmit microwave signals and simultaneously reflect optical signals. Owing to mechanical constrain

In three-dimensional imaging employing phase-shifting profilometry (PSP), the nonlinear response of projector and camera makes the fringe gray distribution non-sinusoidal, which further leads to phase error. Although the double 3-

Effective methods are urgently required to optimize Raman spectroscopy technology to ameliorate its low detection sensitivity. Here, we superposed two near-concentric cavities to develop a dual near-concentric cavities group (DNCC

The alkali-atom density measurement method based on light absorption is highly suitable for a spin-exchange relaxation-free (SERF) atomic magnetometer because of its high-precision measurement and complete nonmagnetic interference

Sensors based on optical resonators often have their measurement range limited by their cavity linewidth, particularly in the measurement of time-varying signals. This paper introduces a method for optical frequency shift detectio

The compact, sensitive, and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging. The metasurface offers a promising solution to develop high-precis

The pandemic of respiratory diseases enlightened people that monitoring respiration has promising prospects in averting many fatalities by tracking the development of diseases. However, the response speed of current optical fiber

We propose a high-sensitivity spin polarization detection scheme based on optical amplitude modulation in atomic co-magnetometers, which is different from the traditional configuration. A linearly polarized laser with intensity mo

A biosensor featuring an S-tapered fiber (STF) with a composite bio-sensitive film comprising graphene oxide and gold nanoparticles, has been proposed for the rapid, highly sensitive, and label-free detection of pseudomonas exotox

A broadband gas sensing technology is reported. The measurement principle relies on Fourier transform photoacoustic spectroscopy (FT-PAS) using a differential photoacoustic cell, in which both phase modulation and amplitude modula

Micromagnets, as a promising technology for microscale manipulation and detection, have been the subject of extensive study. However, providing real-time, noninvasive feedback on the position and temperature of micromagnets in com

The high-sensitivity three-axis detection of magnetic fields is widely used in various applications. Our study demonstrates an atomic magnetometer detecting vector magnetic field, of which the core components are one glass cell an

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

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

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

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

Overlay (OVL) for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process. The tolerance of OVL metrology for the latest microchip needs to be at nanometer sca

In the femtosecond two-photon polymerization (2PP) experimental system, optical aberrations degrade the fabrication quality. To solve this issue, a multichannel interferometric wavefront sensing technique is adopted in the adaptiv

Modulation of a vector light field has played an important role in the research of nanophotonics. However, it is still a great challenge to accurately measure the three-dimensional vector distribution at nanoscale. Here, based on

Aiming at coherence degradation during target detection, a suppressing method based on frequency-modulated continuous wave coherent lidar is proposed. Combined with a random iteration algorithm, a long-pulse echo signal with coher

We proposed and experimentally demonstrated an all-fiber sensor for measuring bend with high sensitivity based on a ring core fiber (RCF) modal interferometer. The sensor was fabricated by splicing a segment of RCF between two pie

We propose a high-sensitivity bidirectional torsion sensor using a helical seven-core fiber taper embedded in multimode fiber (MHSTM). Sensors with different taper waists and helical pitches are fabricated, and their transmission

The self-mixing interferometry (SMI) technique is an emerging sensing technology in microscale particle classification. However, due to the nature of the SMI effect raised by a microscattering particle, the signal analysis suffers

Fabrication of high-quality optics puts a strong demand on high-throughput detection of macroscopic bulk defects in optical components. A dark-field line confocal imaging method is proposed with two distinct advantages: (i) a poin

Laser ranging with frequency comb intermode beats (IMBs) has been suffering from random phase drifts (RPDs) for two decades. In this study, we reveal the influence of signal transmission path on the RPDs and propose a real-time su

Usually, a multilens optical system is composed of multiple undetectable sublenses. Wavefront of a multilens optical system cannot be measured when classical transmitted phase measuring deflectometry (PMD) is used. In this study,

Although previously reported terahertz absorbers can achieve high-sensitivity refractive index sensing, the resonant peak is too broad, which leads to a low figure of merit (FOM). Transmissive sensors based on bound states in the

We propose a new method for the development of multi-beam systems for the spatial alignment and stability of beams based on the error separation technique. This method avoids alignment errors caused by coupling effect of piezoelec

Nitrogen-vacancy (NV) centers in diamond are progressively favored for room-temperature magnetic field measurement. The signal to noise ratio (SNR) optimization for NV diamond magnetometry generally concentrates on signal amplitud

Fluorescence detection is widely used in biology and medicine, while the realization of on-chip fluorescence detection is vital for the portable and point-of-care test (POCT) application. In this Letter, we propose an efficient fl

We propose a method for reconstructing non-diffuse surfaces based on the π-phase-shifted two-plus-one phase-shifting method. First, we introduce a 2fH + a + 2fM + 2fL method for unwrapped phase extraction. Subsequently, we introdu

In this Letter, we propose a simple structure of an orthogonal type double Michelson interferometer. The orthogonal detection method overcomes the problems of uneven ranging sensitivity and the inability of traditional interferome

Studies on the kinetics of gas-phase chemical reactions currently rely on calculations or simulations and lack simple, fast, and accurate direct measurement methods. We developed a tunable laser molecular absorption spectroscopy m

Nitrogen-vacancy color centers can perform highly sensitive and spatially resolved quantum measurements of physical quantities such as magnetic field, temperature, and pressure. Meanwhile, sensing so many variables at the same tim

Film thickness measurement can be realized using white light interferometry, but it is challenging to guarantee high precision in a large range of thicknesses. Based on scanning white light interferometry, we propose a spectral-te

Based on Autler–Townes splitting and AC Stark shifts, we present a Rydberg atom-based receiver for determining the amplitude modulation (AM) frequency among a wideband carrier range utilizing a cesium atomic vapor cell. To verify

We propose a dual-mode optically pumped magnetometer (OPM) that can flexibly switch between single-beam modulation mode and double-beam DC mode. Based on a 4 mm×4 mm×4 mm miniaturized vapor cell, the double-beam DC mode achieves a

Real-time monitoring of wavelength is important for high-speed wavelength phase-shifting interferometry. In this paper, a wavelength sensor based on a polarization-maintaining fiber interferometer with four-quadrant demodulation w

A sensor based on light-induced thermoelastic spectroscopy (LITES) with a fiber-coupled multipass cell was demonstrated for carbon monoxide (CO) detection. The fiber-coupled structure has the merits of reducing optical interferenc

We demonstrate the stabilization of an optical frequency comb (OFC) using a segment of fiber delay line as a reference. A mode-locked Er-doped fiber laser is phase locked to a kilometer-long fiber delay line using three different

The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters or character

We demonstrate a multi-channel pseudo-random coding single-photon ranging system. A pseudo-random multiplexing technique is proposed, which realizes multi-channel pseudo-random ranging only by using one single-photon detector and

A high performance optical sensor based on a double compound symmetric gratings (DCSGs) structure is designed. The reflection spectrum of the DCSG is investigated by utilizing a method that combines a theoretical model with the ei

We present and demonstrate a multifunctional single-fiber optical tweezer for particle trapping and transport. The fiber probe of fiber optical tweezers is constructed as a planar structure. Laser sources with wavelengths of 650 n

A high-sensitivity DC magneto-optical Kerr effect (MOKE) apparatus is described in this Letter. Via detailed analysis on several dominating noise sources, we have proposed solutions that significantly lower the MOKE noise, and a s

In this paper, we present a suppression method for the thermal drift of an ultra-stable laser interferometer. The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temper

In this paper, a novel liquid level sensor with ultra-high sensitivity is proposed. The proposed sensor is configured by a slice-shaped composite long period fiber grating (SSC-LPFG). The SSC-LPFG is prepared by polishing two oppo

A key limitation in the observation of instruments used in operations and heart sutures during a procedure is the scattering and absorption during optical imaging in the presence of blood. Therefore, we propose a novel real-time f

The femtosecond laser has been an efficient tool for optical fiber high temperature sensor construction. Here, we review the progress of optical fiber high temperature sensors based on femtosecond laser fabricated fiber gratings a

A full-open-cavity wavelength-tunable random fiber laser (WT-RFL) with compact structure and hundreds of picometers tuning range is proposed and demonstrated. A π fiber Bragg grating (FBG) is used in the WT-RFL as a filter to sele

A novel reconstruction method of nanometer micro-displacement of Fabry–Perot (F-P) interference is proposed in this study. Hilbert transforms are performed for F-P interference fringes, and the obtained signal performs tangent ope

The distributed optical fiber surface plasmon resonance (SPR) sensors have attracted wide attention in biosensing and chemical sensing applications. However, due to the limitation of their sensing structure, it is difficult to adj

We develop a low frequency fiber Fabry–Perot (F-P) seismometer based on transfer function analysis. The seismometer structure and demodulation system accuracy are limitations of low frequency seismic monitoring. The transfer funct

We propose and investigate a compact optical fiber sensor that aims to measure the torsion in both amount and direction with high sensitivity. This sensor is configured by a triangular-prism-shaped long-period fiber grating, which

A fiber-optic sensor for the simultaneous measurement of strain and temperature is proposed and experimentally demonstrated based on Fabry–Pérot (FP) interference and the antiresonance (AR) mechanism. The sensor was implemented us

Natural logarithm wavelength modulation spectroscopy (ln-WMS) is demonstrated in this Letter. Unlike the conventional wavelength modulation spectroscopy (WMS)-2f technique, it is a linear method even for large absorbance, which is

We report a spatially modulated polarimetry scheme by using a zero-order vortex half-wave retarder (ZVHR) and a spatial Fourier analysis method. A ZVHR is employed to analyze the input polarized light and convert it into a vectori

A broadband instantaneous multi-frequency measurement system based on chirped pulse compression, which potentially has a sub-megahertz (MHz) accuracy and a hundred-gigahertz (GHz) measurement range, is demonstrated. A signal-under

In this Letter, the periodical errors, which are caused by the nonlinear effect of the commercial projector and camera, are analyzed as a more generic single-coefficient model. The probability density function of the wrapped phase

In order to improve the accuracy and universality of the rotational speed measurement, an instantaneous rotational speed measurement method based on laser Doppler technology is proposed. The composition and working principle of th