The next generation of mobile communication is committed to establishing an integrated three-dimensional network that encompasses air, land, and sea. The visible light spectrum is situated within the transmission window for underw

Neural networks (NNs), especially electronic-based NNs, have been rapidly developed in the past few decades. However, the electronic-based NNs rely more on highly advanced and heavy power-consuming hardware, facing its bottleneck

Integrating distributed ultra-low-frequency vibration sensing and high-speed fiber optical communication can provide additional functionality under the current submarine telecommunication network, such as ocean seismic monitoring

Beyond providing user access to the core network, the radio access network (RAN) is expected to support precise positioning and sensing for emerging applications such as virtual reality (VR) and drone fleets. To achieve this, fron

Driven by advancements in artificial intelligence, end-to-end learning has become a key method for system optimization in various fields, including communications. However, applying learning algorithms such as backpropagation dire

The performance of an all-fiber-integrated photodetector (AFPD) depends on the integration of the active layer, where FA0.4MA0.6PbI3 emerges as a promising candidate due to its high absorbance, long carrier diffusion distance, and

Semiconductor metal oxides with narrow bandgap have emerged as a promising platform for photoelectrochemical reactions, yet their photoelectron-induced photocorrosion effect has been a limitation for their wider applications. Unde

The photonic frequency-interleaving (PFI) technique has shown great potential for broadband signal acquisition, effectively overcoming the challenges of clock jitter and channel mismatch in the conventional time-interleaving parad

Space-division multiplexing (SDM) systems based on few-mode multi-core fibers (FM-MCFs) utilize both spatial channels (fiber cores) and modes (optical modes per core) to maximize transmission capacity. Unlike laboratory FM-MCFs or

Rayleigh backscattering enhancement (RSE) of optical fibers is an effective means to improve the performance of distributed optical fiber sensing. Femtosecond laser direct-writing techniques have been used to modulate the fiber co

Independent light propagation through one or multiple modes is commonly considered as a basic demand for mode manipulation in few-mode fiber (FMF)- or multimode fiber (MMF)-based optical systems such as transmission links, optical

Heat generated by the quantum defect (QD) in optically pumped lasers can result in detrimental effects such as mode instability, frequency noise, and even catastrophic damage. Previously, we demonstrated that boson-peak-based Rama

The propagation of coherent light in multimode optical fibers results in a speckled output that is both complex and sensitive to environmental effects. These properties can be a powerful tool for sensing, as small perturbations le

Data centers, the engines of the global Internet, rely on powerful high-speed optical interconnects. In optical fiber communication, classic direct detection captures only the intensity of the optical field, while the coherent det

Secure distribution of high-speed digital encryption/decryption keys over a classical fiber channel is strongly pursued for realizing perfect secrecy communication systems. However, it is still challenging to achieve a secret key

Noninvasive high-resolution deep-brain imaging is essential to fundamental cognitive process study and neuroprotective drugs development. Although optical microscopes can resolve fine biological structures with good contrast witho

Multidimensional optical multicasting can increase the number of multicast optical channels and enhance spectrum utilization, which is crucial for future high-capacity optical networks and high-performance optical computing. Howev

Traditional optical communication systems employ bulky laser arrays that lack coherence and are prone to severe frequency drift. Dissipative Kerr soliton microcombs offer numerous evenly spaced optical carriers with a high optical

We propose and demonstrate a superfine multiresonant fiber grating sensor characterized by superior spectral resolution and enhanced sensing capabilities. This sensor can be easily constructed by inserting a tilted fiber Bragg gra

The demand for real-time feedback and miniaturization of sensing elements is a crucial issue in the treating vascular diseases with minimally invasive interventions. Here, Fabry–Perot microcavities fabricated via direct laser writ

The sensing spatial resolution and signal-to-noise ratio (SNR) of Raman distributed optical fiber sensors are limited by the pulse width and weak Raman scattering signals. Notably, the sensing spatial resolution cannot exceed the

Multi-wavelength-band transmission technology based on the exploitation of the extended spectral region is considered as a potential approach to increase the transmission capacity in the deployed fiber-optic communication infrastr

Mode purity measurement is crucial for various applications utilizing few-mode fibers and related devices. In this paper, we propose a simple and accurate method for measuring the mode purity of the output optical field in few-mod

Optical fiber distributed acoustic sensing (DAS) based on phase-sensitive optical time domain reflectometry (φ-OTDR) is in great demand in many long-distance application fields, such as railway and pipeline safety monitoring. Howe

Optical chaos communication and key distribution have been extensively demonstrated with high-speed advantage but only within the metropolitan-area network range of which the transmission distance is restricted to around 300 km. F

Space-to-ground high-speed transmission is of utmost importance for the development of a worldwide broadband network. Mid-infrared wavelengths offer numerous advantages for building such a system, spanning from low atmospheric att

Photonic technology combined with artificial intelligence plays a key role in the development of the latest smart system trends, integrating cutting-edge technology with machine learning models. This paper proposes a transmission-

Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications. Due to the chaotic bandwidth limitatio

Light propagation in random media is a subject of interest to the optics community at large, with applications ranging from imaging to communication and sensing. However, real-time characterization of wavefront distortion in rando

The ability to sense heat and touch is essential for healthcare, robotics, and human–machine interfaces. By taking advantage of the engineerable waveguiding properties, we design and fabricate a flexible optical microfiber sensor

Multicolor series connection micro-LED arrays with emission wavelengths of violet, blue, green, and yellow were fabricated, and their optoelectronic properties and communication performances were investigated. The designed series

Three-dimensional (3D) imaging radar is an advanced sensor applied in space surveillance and target recognition for supplying 3D geometric features and supporting visualization. However, high 3D resolution requires both broadband

As the main branch of microwave photonics, radio-over-fiber technology provides high bandwidth, low-loss, and long-distance propagation capability, facilitating wide applications ranging from telecommunication to wireless networks

Atoms ionization by the simultaneous absorption of multiple photons has found applications in fiber optics, where it leads to unique nonlinear phenomena. To date, studies of the ionization regime have been limited to gas-filled ho

We created an all-fiber solution for fast, continuous, and controllable tuning of Fano-like resonance. By embedding a graphene-coated fiber Bragg grating into one arm of a Mach–Zehnder interferometer, the narrow Bragg resonance in

The typical functions of the optical fiber are communication and sensing. However, the fiber functions need to extend to meet the requirements of the development of artificial intelligence. This paper achieves an all-fiber device

An integrated few-mode erbium-doped fiber amplifier (FM-EDFA) with high modal gain is suitable for the in-line amplification in mode-division multiplexing transmission (MDM) systems. We first experimentally demonstrate a dual-stag

Space-division multiplexing based on few-mode multi-core fiber (FM-MCF) technology is expected to break the Shannon limit of a single-mode fiber. However, an FM-MCF is compact, and it is difficult to couple the beam to each fiber

Visible light communication (VLC) has emerged as a promising communication method in 6G. However, the development of receiving devices is much slower than that of transmitting devices, limited by materials, structures, and fabrica

Raman distributed optical fiber sensing is required to achieve accurate temperature measurements in a micro-scale area. In this study, we first analyze and demonstrate the pulse transmission feature in the temperature variation ar

Aging degradation and seismic damage of civil infrastructures have become a serious issue for society, and one promising technology for monitoring their conditions is optical fiber sensing. Glass optical fibers have been predomina

High-speed visible light communication (VLC) using light-emitting diodes (LEDs) is a potential complementary technology for beyond-5G wireless communication networks. The speed of VLC systems significantly depends on the quality o

We report the use of a terahertz (THz) transparent material, cyclic olefin copolymer (COC or TOPAS), for fabricating a hollow-core antiresonant fiber that provides an electromagnetic wave guidance in the THz regime. A novel fabric

Stokes vector direct detection is a promising, cost-effective technology for short-distance communication applications. Here, we design and fabricate a spin-dependent liquid crystal grating to detect light polarization states. By

Light-emitting diodes (LEDs) are widely used for data transmission in emerging optical wireless communications (OWC) systems. This paper analyzes the physical processes that limit the bandwidth and cause nonlinearities in the ligh

The interaction of random laser and gain medium is important to understand the noise origin in random fiber lasers. Here, using the optical time domain reflectometry method, the time-resolved distributed acoustic wave generated by

Experimental and numerical studies of spatiotemporal femtosecond soliton propagation over up to 1 km spans of parabolic graded-index fibers reveal that initial multimode soliton pulses naturally and irreversibly evolve into a sing

A single-frequency distributed Bragg reflector (DBR) fiber laser at 1030 nm has been demonstrated using a 0.7 cm long homemade Yb:YAG crystal-derived silica fiber (YCDSF). The absorption and emission cross sections of the YCDSF ar

Visible light communication (VLC) is currently recognized as a relevant technology for a wealth of possible application scenarios. New classes of services can be designed in both outdoor and indoor environments, exploiting the dir

High-capacity, long-distance underwater optical communication enables a global scale optical network covering orbit, land, and water. Underwater communication using photons as carriers has a high channel capacity; however, the lig

We demonstrate the fabrication of single-mode helical Bragg grating waveguides (HBGWs) in a multimode coreless fiber by using a femtosecond laser direct writing technique. This approach provides a single-step method for creating B

We propose an optomechanical system to quantify the net force on a strand of cleaved silica optical fiber in situ as the laser light is being guided through it. Four strands of the fiber were bonded to both sides of a macroscopic

In this study, a novel rectangular polymer single-mode optical fiber for femtosecond (fs) laser-inscribed fiber Bragg gratings (FBGs) is proposed and demonstrated. The cylindrical geometry of the widely used circular fiber elongat

Untrusted node networks initially implemented by measurement-device-independent quantum key distribution (MDI-QKD) protocol are a crucial step on the roadmap of the quantum Internet. Considering extensive QKD implementations of tr

We experimentally demonstrate mode-division multiplexed (MDM) transmission using eight orbital angular momentum (OAM) modes over a single span of 100-km low-attenuation and low-crosstalk ring-core fiber (RCF). Each OAM mode channe

In this study, a high-sensitivity, high-spatial-resolution distributed strain-sensing approach based on a poly(methyl methacrylate) chirped fiber Bragg grating (CFBG) is proposed and experimentally demonstrated. Linearly chirped F

A phase demodulation method for quasi-distributed acoustic sensing (DAS) systems based on a dual-identical-chirped-pulse and weak fiber Bragg gratings (WFBGs) is proposed. Compared to the use of Rayleigh backscattering light in op

Data signals consisting of arbitrarily modulated sequences of pulses are extensively used for processing and communication applications. The spectral extent of such signals is determined by the bandwidth of the individual pulses i

The experimental investigation of mode distortion induced by stimulated Raman scattering (SRS) in a high-power fiber amplifier, which includes the evolutions of optical spectra, spatial beam profiles, and time-frequency characteri

The radical suppression of the photodarkening effect and laser performance deterioration via H2 loading were demonstrated in high-power Yb-doped fiber (YDF) amplifiers. The photodarkening loss at equilibrium was 114.4 dB/m at 702

A theoretical and experimental study on curvature sensing using a Brillouin optical time-domain analyzer based on the ring-core fiber (RCF) is reported. The Brillouin gain spectrum of the RCF is investigated, and the Brillouin fre

Terahertz (THz) band (0.1–10 THz) is the next frontier for ultra-high-speed communication systems. Currently, most of communications research in this spectral range is focused on wireless systems, while waveguide/fiber-based links

The flexibile nature of optical fiber enables it to offer remote-access capabilities, which could be used in many biomedical applications. This review focuses on different micro- and nano-structured fiber probes for applications i

A short absorption length ytterbium (Yb)-doped large-mode area (LMA) fiber is presented as a step forward to mitigate the stern problem of nonlinear scatterings in a tandem pumping scheme adopted for high-power fiber laser. The sh

Visible light communication based on light-emitting diodes (LEDs) has become a promising candidate by providing high data rates, low latency, and secure communication for underwater environments. In this paper, a self-designed com

We propose a mode demultiplexing hybrid (MDH) that integrates mode demultiplexing, local oscillator power splitting, and optical 90-deg mixing using multi-plane light conversion (MPLC). We demonstrate the realization of a three-mo

Optical chirp chain Brillouin optical time-domain analysis (OCC-BOTDA) has the capabilities of fast measurement, high Brillouin threshold, and freedom from the nonlocal effect; at the same time, however, it also has problems intro

We demonstrate a passively mode-locked all-fiber laser generating cylindrical vector beams (CVBs) only using a symmetric two-mode fiber optical coupler (TMF-OC) for both high-order mode excitation and splitting. Theoretical analys

In this paper, an integrated compact four-channel directly modulated analog optical transceiver is proposed and fabricated. The 3 dB bandwidth of this optical transceiver exceeds 20 GHz, and the measured spurious-free dynamic rang

For space missions, there is a need for fiber lasers of minimum power consumption involving stabilized frequency combs. We exploit the extreme sensitivity of the polarization state of circularly polarized light sent through polari

A method is presented for one-to-many information encryption transmission by using temporal ghost imaging and code division multiple access. In the encryption transmission process, code division multiple access technologies combin

We propose to use the low-coherence property of amplified spontaneous emission (ASE) noise to mitigate optical crosstalk, such as spatial, polarization, and modal crosstalk, which currently limits the density of photonic integrati

We propose and experimentally demonstrate a novel physical layer encryption scheme for high-speed optical communication. A 10 Gb/s on-off keying signal is secretly transmitted over 100 km standard single-mode fiber. The intensity-

We report a quantum key distribution (QKD) system that uses light-emitting-diodes (LEDs) at 1310 nm as optical sources. Compared to the normally used laser diodes (LDs), LEDs are easier to manufacture and integrate, and thus have

Graphene microfibers are burgeoning modulators with great potential in all-optical communication. One of the critical issues that remains to be understood is the dynamic mechanism of light–graphene interaction. Here, we propose a

The quickly increasing data transfer load requires an urgent revolution in current optical communication. Orbital angular momentum (OAM) multiplexing is a potential candidate with its ability to considerably enhance the capacity o

We propose and experimentally demonstrate a recorded 1-m bidirectional 20.231-Gbit/s tricolor R/G/B laser diode (LD) based visible-light communication (VLC) system supporting signal remodulation. In the signal remodulation system,

High-speed multi-user access with high spectral efficiency is one of the key challenges for band-limited visible light communication (VLC) systems. In this paper, we propose a novel scheme for effective multiple-access VLC systems

We propose a novel waveguide design of a polarization-maintaining few mode fiber (PM-FMF) supporting ≥10 non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a n

Light-emitting diode (LED)-based visible light communication (VLC) has become a potential candidate for nextgeneration ultra-high-speed indoor wireless communication. In this paper, four special-shaped 8-quadrature amplitude modul

Core mode cutoff is a useful concept not only for a tapered single-core fiber (SCF) but also for a tapered multicore fiber (MCF) to realize cladding mode transmission. In this paper, cut-off conditions of either core mode for tape

In this paper, we present a mode-selective coupler based on a dual-core all-solid photonic bandgap fiber (AS-PBGF). Because they are all-solid, AS-PBGF-based mode converters are easier to splice to other fibers than those based on