On the Cover: Flexible 2 × 2 multiple access visible light communication system based on an integrated parallel GaN/InGaN micro-photodetector array module
On the Cover: Optical bound states in the continuum in periodic structures: mechanisms, effects, and applications
On the Cover: Detailed characterization of kHz-rate laser-driven fusion at a thin liquid sheet with a neutron detection suite
On the Cover: Generation of subwavelength inverted pin beam via fiber end integrated plasma structure
On the Cover: High performance and stable pure-blue quasi-2D perovskite light-emitting diodes by multifunctional zwitterionic passivation engineering

A GaN-based visible light array receiver enables high-speed short-wavelength multi-access applications in visible light laser communication networks in the upcoming 6G era.

The con?nement of waves is a long-standing pursuit in both fundamental science and practical applications. Recent exploration of bound states in the continuum (BICs) has introduced novel approaches for e?ectively trapping light waves. With additional degrees of polarization freedom in momentum space, optical BICs are driving innovation in areas such as spin-orbit interactions and light-matter interactions.

The image presents a depiction of laser-driven deuterium fusion, where a high repetition-rate femtosecond pulse laser is focused onto a thin layer of heavy water (deuterium oxide). Upon laser irradiation, two deuterium nuclei within the heavy water undergo fusion to form a pair of relativistic neutron and helium nucleus. The backdrop features artistic representations of deuterated water molecules, emphasizing the use of a submicron sheet of liquid heavy water as the primary material for the target to achieve the fusion process. The visual showcases a dynamic interplay between light and matter, with a colorful and energetic contrast that highlights the fusion reaction taking place.

The image on the cover illustrates an all-?ber subwavelength structured light beam generator based on the ?ber end integrated plasma structure. It can generate a kind of novel subwavelength structured light beam, an inverted pin beam.

Perovskite light-emitting diodes (PeLEDs) are considered promising candidates for future display and lighting technologies due to their excellent optoelectronic properties and simple fabrication methods. The introduction of the zwitterionic molecule 3-(benzyldimethylammonio)propanesulfonate (3-BAS) serves multiple purposes: it passivates defects on the perovskite surface, suppresses the migration of halide ions, and e?ectively regulates the crystallization process of perovskite thin ?lms. The image on the cover illustrates blue LEDs based on perovskites and suggests potential application prospects in future visible light communication.

Community-News
The Extreme Light Infrastructure User Meeting 2024
The Extreme Light Infrastructure (ELI) User Meeting will take place on 26-28 June 2024 as an in-person event, hosted by the ELI Beamlines Facility in Dolni Brezany, Czech Republic.
High Power Laser Science and Engineering
  • May. 28, 2024
  • Vol. , Issue (2024)
AP Highlights
Iso-propagation vortices: optical multiplexing for unprecedented information capacity
A new type of vortex beams with OAM-independent propagation overcomes historical limitations related to beam divergence, a breakthrough for optical communication
Advanced Photonics
  • May. 24, 2024
  • Vol. 6, Issue 3 (2024)
Editors' Picks
Lead-free perovskite Cs2AgBiBr6 photodetector detecting NIR light driven by titanium nitride plasmonic hot holes
Near-infrared photodetectors play increasingly roles in many fields, such as autonomous driving, food safety, medical imaging, machine vision, biometrics, and smart agriculture. However, traditional near-infrared photodetectors are mainly made of inorganic semiconductor materials such as germanium and indium gallium arsenide, which are expensive in the manufacturing process and lack mechanical flexibility and biocompatibility, thus limiting their application range to a certain extent. As a result, detectors based on solution-processable semiconductors are attracting attention, as they offer significant advantages in terms of cost, flexibility, and biocompatibility. Among them, perovskite materials have attracted attention for their excellent optoelectronic properties. However, the toxic element Pb in lead halide perovskites limits their commercialization. Therefore, it is necessary to study lead-free perovskite materials.
Photonics Research
  • May. 24, 2024
  • Vol. 12, Issue 3 (2024)
Editors' Picks
High-performance, low-power, and flexible ultraviolet photodetector based on crossed ZnO microwires p-n homojunction
With the continuous development of science and technology, there is an increasing demand for lightweight, low-power, portable wearable devices, resulting in flexible photodetectors that have great potential and broad market prospects for future practical applications. These detectors are usually highly flexible and can maintain good performance on different curved surfaces and shapes, which is of great significance in meeting the ever-changing market demands of modern technological products. While future flexible photodetectors may focus more on integration and intelligence, to realize the popularity of electronic devices used for smart wearables, many sensors must be integrated into various forms of wearable systems, including clothing, watches, contact lenses, and electronic skin. Therefore, it is crucial to integrate multiple detectors into a miniature system. With advances in materials science and micro-nano technology, the size and weight of flexible photodetectors are expected to be further reduced, making them more suitable for miniaturized and portable devices. The ZnO microwires (MWs) are promising candidates for building highly sensitive ultraviolet (UV) detectors with flexibility, low power consumption, high efficiency and integrability, which could create new possibilities for human wearable systems.
Photonics Research
  • May. 24, 2024
  • Vol. 12, Issue 4 (2024)
On the Cover
A tunable hexagonal boron nitride topological optical delay line in the visible region
With the current development of information science and technology, the emergence of new technologies, such as automatic driving, remote medical care, and cloud computing, has dramatically increased the demand for information processing speed and capacity. It can be used to handle computing tasks that are difficult to solve by traditional computers, such as cryptography, molecular simulation, and big data processing, and has high speed and low power consumption. Those characteristics can meet the rapidly growing computational needs. The development of large-scale applications of optical quantum technology requires densely integrating nanophotonic devices on photonic chips. Therefore, information interaction and computation based on photonic chips is a fulcrum technology for the entire information field in the future and has a far-reaching market and strategic significance in information technology, national defense and security, energy, health care and other fields.
Chinese Optics Letters
  • May. 23, 2024
  • Vol. 22, Issue 5 (2024)
Newest Articles
Spectral-interferometry-based diff-iteration for high-precision micro-dispersion measurement

Precise measurement of micro-dispersion for optical devices (optical fiber, lenses, etc.) holds paramount significance across domains such as optical fibe

Precise measurement of micro-dispersion for optical devices (optical fiber, lenses, etc.) holds paramount significance across domains such as optical fiber communication and dispersion interference ranging. However, due to its complex system, complicated process, and low reliability, the traditional dispersion measurement methods (interference, phase shift, or time delay methods) are not suitable for the accurate measurement of micro-dispersion in a wide spectral range. Here, we propose a spectral-interferometry-based diff-iteration (SiDi) method for achieving accurate wide-band micro-dispersion measurements. Using an optical frequency comb, based on the phase demodulation of the dispersion interference spectrum, we employ the carefully designed SiDi method to solve the dispersion curve at any position and any order. Our approach is proficient in precisely measuring micro-dispersion across a broadband spectrum, without the need for cumbersome wavelength scanning processes or reliance on complex high-repetition-rate combs, while enabling adjustable resolution. The efficacy of the proposed method is validated through simulations and experiments. We employed a chip-scaled soliton microcomb (SMC) to compute the dispersion curves of a 14 m single-mode fiber (SMF) and a 0.05 m glass. Compared to a laser interferometer or the theoretical value given by manufacturers, the average relative error of refractive index measurement for single-mode fiber (SMF) reaches 2.8×10-6 and for glass reaches 3.8×10-6. The approach ensures high precision, while maintaining a simple system structure, with realizing adjustable resolution, thereby propelling the practical implementation of precise measurement and control-dispersion.show less

  • May.30,2024
  • Photonics Research,Vol. 12, Issue 6
  • 1362 (2024)
Wavelength-dependent nonlinear wavefront shaping in 3D nonlinear photonic crystal

A 3D nonlinear photonic crystal containing four parallel segments of periodic χ(2) grating structure is fabricated employing the femtosecond laser poling

A 3D nonlinear photonic crystal containing four parallel segments of periodic χ(2) grating structure is fabricated employing the femtosecond laser poling of ferroelectric Ca0.28Ba0.72Nb2O6 crystal. The second harmonic generation from this four-segment structure is studied with a fundamental Gaussian wave. By tuning the wavelength of the fundamental wave, the second harmonic varies from the Laguerre–Gaussian beam (topological charge lc = 1) to the higher-order Hermite–Gaussian beam and Laguerre–Gaussian again (lc = -1). This effect is caused by the wavelength-dependent phase delays introduced by the four-grating structure. Our study contributes to a deeper understanding of nonlinear wave interactions in 3D nonlinear photonic crystals. It also offers new possibilities for special beam generation at new frequencies and their control.show less

  • May.30,2024
  • Chinese Optics Letters,Vol. 22, Issue 7
  • 071901 (2024)
Highly sensitive mid-infrared upconversion detection based on external-cavity pump enhancement

Sensitive mid-infrared (MIR) detection is in high demand in various applications, ranging from remote sensing, infrared surveillance, and environmental mo

Sensitive mid-infrared (MIR) detection is in high demand in various applications, ranging from remote sensing, infrared surveillance, and environmental monitoring to industrial inspection. Among others, upconversion infrared detectors have recently attracted increasing attention due to their advantageous features of high sensitivity, fast response, and room-temperature operation. However, it remains challenging to realize high-performance passive MIR sensing due to the stringent requirement of high-power continuous-wave pumping. Here, we propose and implement a high-efficiency and low-noise MIR upconversion detection system based on pumping enhancement via a low-loss optical cavity. Specifically, a single-longitudinal-mode pump at 1064 nm is significantly enhanced by a factor of 36, thus allowing for a peak conversion efficiency of up to 22% at an intracavity average power of 55 W. The corresponding noise equivalent power is achieved as low as 0.3 fW / Hz1/2, which indicates at least a 10-fold improvement over previous results. Notably, the involved single-frequency pumping would facilitate high-fidelity spectral mapping, which is particularly attractive for high-precision MIR upconversion spectroscopy in photon-starved scenarios.show less

  • May.30,2024
  • Advanced Photonics Nexus,Vol. 3, Issue 4
  • 046002 (2024)
Ultra-wide FOV meta-camera with transformer-neural-network color imaging methodology

Planar cameras with high performance and wide field of view (FOV) are critical in various fields, requiring highly compact and integrated technology. Exis

Planar cameras with high performance and wide field of view (FOV) are critical in various fields, requiring highly compact and integrated technology. Existing wide FOV metalenses show great potential for ultrathin optical components, but there is a set of tricky challenges, such as chromatic aberrations correction, central bright speckle removal, and image quality improvement of wide FOV. We design a neural meta-camera by introducing a knowledge-fused data-driven paradigm equipped with transformer-based network. Such a paradigm enables the network to sequentially assimilate the physical prior and experimental data of the metalens, and thus can effectively mitigate the aforementioned challenges. An ultra-wide FOV meta-camera, integrating an off-axis monochromatic aberration-corrected metalens with a neural CMOS image sensor without any relay lenses, is employed to demonstrate the availability. High-quality reconstructed results of color images and real scene images at different distances validate that the proposed meta-camera can achieve an ultra-wide FOV (>100 deg) and full-color images with the correction of chromatic aberration, distortion, and central bright speckle, and the contrast increase up to 13.5 times. Notably, coupled with its compact size (< 0.13 cm3), portability, and full-color imaging capacity, the neural meta-camera emerges as a compelling alternative for applications, such as micro-navigation, micro-endoscopes, and various on-chip devices.show less

  • May.30,2024
  • Advanced Photonics,Vol. 6, Issue 5
  • 056001 (2024)
Advanced Photonics Photonics Insights

Recently, artificial intelligence(AI) has been proven as an effective modeling tool in ultrafast optics and its application in the design of ultrafast laser system is a promising issue. In this

Recently, artificial intelligence(AI) has been proven as an effective modeling tool in ultrafast optics and its application in the design of ultrafast laser system is a promising issue. In this Letter, a method based on a feed-forward neural network (FNN) model with simple structure is adopted to inversely predict the full-field supercontinuum generation (SCG) and recover the initial pulse. The performance of the FNN and its dependence on the predicted pulse features are further explored by a reconstruction test. The generalization ability of the method is further demonstrated in the case with initial chirp.show less

  • May.30,2024
  • Chinese Optics Letters,Vol. 22, Issue 11
  • (2024)

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

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 exotoxin (PE). The STF was created using a fusion splicer; subsequently, the composite film and nanobody were successively assembled onto its surface. The detection mechanism relies on monitoring changes in the external refractive index induced by the specific binding of PE to the nanobody. The developed STF biosensor exhibited a remarkable sensitivity of 0.28 nm/(ng/mL) and a limit of detection as low as 0.21 ng/mL for PE.show less

  • May.30,2024
  • Chinese Optics Letters,Vol. 22, Issue 11
  • (2024)

A novel electro-optic deflector based on a quadratic electro-optical KLTN crystal operating slightly above the ferroelectric phase transition is presented. The new deflection scheme was based on

A novel electro-optic deflector based on a quadratic electro-optical KLTN crystal operating slightly above the ferroelectric phase transition is presented. The new deflection scheme was based on the electric field gradient generation along the vertical axis caused by the trapezoidal geometry of the crystal. A deflection angle of 6.5mRad was attained for a low voltage of 680V. The deflector was used as an electro-optic modulator for implementing active Q-switching in a Tm:YLF laser (1880nm). The laser was operated at three different repetition rates of 0.4, 0.5, 0.7kHz, and reached high energies per pulse up to 6.9mJ.show less

  • May.30,2024
  • High Power Laser Science and Engineering

The dependence of third-order nonlinear optical absorption and carrier dynamics on the thickness of Chromium thiophosphate (CrPS4) is investigated. The I-scan system can obtain nonlinear optical

The dependence of third-order nonlinear optical absorption and carrier dynamics on the thickness of Chromium thiophosphate (CrPS4) is investigated. The I-scan system can obtain nonlinear optical parameters by measuring the transmittance of materials as a function of incident laser intensities. Utilizing the I-scan system, we have observed the typical two-photon absorption (TPA) at 780 nm for three different thicknesses. The TPA coefficient, third-order nonlinear optical susceptibility Imχ(3), and the figure of merit (FOM) have been obtained by fitting the I-scan data. The Imχ(3) significantly increases as the thickness of the sample decreases, while the FOM remains comparatively unaffected. By the non-degenerate pump-probe measurements, the photoinduced absorption has been observed, and the carrier relaxation processes are phonon-assisted with the relaxation time manipulated by varying the thickness and pump intensity. This study provides deep insights into the nonlinear optical properties of CrPS4, which is of great significance for potential applications in ultrafast optical devices.show less

  • May.30,2024
  • Chinese Optics Letters,Vol. 22, Issue 11
  • (2024)