The fifth anniversary of Advanced Photonics
On the Cover: Terahertz polarization sensing, chirality enhancement, and specific binding based on metasurface sensors for biochemical detection: a review [Invited]
Advanced Imaging | Open for Submissions Now!
On the Cover: Coherent free-electron light sources
On the Cover: Achieving higher photoabsorption than group III-V semiconductors in ultrafast thin silicon photodetectors with integrated photon-trapping surface structures

As we mark the fifth anniversary of Advanced Photonics, we are filled with immense pride and gratitude for the remarkable journey we have undertaken together with our authors, readers, reviewers, Editorial Board, and publishers.

The image shows the application of multifunctional and multitype metasurfaces in biochemical sensing. In the middle of the image, it is shown that metasurfaces with different functions generate different chiral light fields under the excitation of incident THz waves so that various biomolecules on the surface can be detected.

A general concept of optical undulator which consists of micro- or nano-scale photon quasi-particles, provides the modulation force necessarily for free electron radiation emission. It paves the way toward compact free electron coherent light sources.

The cover image illustrates a novel engineering technique utilizing photon-trapping surface structures to experimentally demonstrate an extraordinary improvement of photoabsorption in thin silicon that surpasses the inherent absorption e?ciency of gallium arsenide for a broad spectrum of wavelengths.

Community-Publication
Designing a cost-effective X-ray free electron lasers facility
Many advances in structural science since the 1970s were made by probing materials with synchrotron radiation: that is, high energy X-rays generated through accelerating high-energy electrons. The latest generation of such sources, X-ray free electron lasers (XFEL), are far more powerful than their predecessors but are only accessible to international consortia and a few rich countries because of their high cost.
High Power Laser Science and Engineering
  • Apr. 16, 2024
  • Vol. , Issue (2024)
Community-News
Ignition Takes Center Stage at NIF and JLF User Groups Meeting
Ignition was the dominant theme at this year's LLNL National Ignition Facility and Jupiter Laser Facility (NIF and JLF) User Groups Meeting.
High Power Laser Science and Engineering
  • Apr. 11, 2024
  • Vol. , Issue (2024)
Community-News
Nathalie Picqué accepts dual appointment in Berlin
The experimental physicist joins the Max Born Institute as a new Director and has accepted a chair at Humboldt University of Berlin.
High Power Laser Science and Engineering
  • Apr. 11, 2024
  • Vol. , Issue (2024)
Spotlight on Optics
Lensless polarimetric coded ptychography for high-resolution, high-throughput gigapixel birefringence imaging on a chip
Polarimetric imaging, as a novel optical imaging technique, is widely used in fields such as biomedicine, object recognition, polarimetric remote sensing, and 3D imaging. In the field of biomedicine, polarimetric imaging has two unique advantages compared to traditional optical imaging: 1) By analyzing the polarization properties of light interacting with biospecimens, microscopic-level information about the composition and structure can be obtained without requiring labeling agents. For example, collagen fibers in connective tissues can alter the polarization state of light passing through them. Measuring this alteration provides information about collagen fiber orientation and density, which are associated with various diseases such as cancer and fibrosis. 2) By selectively filtering out light waves with certain polarization states, it is possible to enhance image contrast and improve the visibility of certain structures or components based on the birefringence maps.
Photonics Research
  • Apr. 11, 2024
  • Vol. 11, Issue 12 (2024)
On the Cover
Constructing arbitrary self-similar Bessel-like beams via transverse-longitudinal mapping
Since the Bessel beam was proposed as an exact solution of propagation-invariant mode to the Helmholtz equation by Durnin in 1987, it has attracted a great deal of research interests. Due to its properties of non-diffraction and self-healing, the Bessel beam has been widely used in the fields of free-space optical interconnects and communications, optical capture and particle manipulation, optical micro-nano machining, optical microscopic imaging, and femtosecond laser processing. Recently, the propagation and manipulation of Bessel beams have become an issue of fundamental importance.
Chinese Optics Letters
  • Apr. 10, 2024
  • Vol. 22, Issue 2 (2024)
Newest Articles
A simple method for pulse contrast enhancement via self-focusing

Here we report on a simple-to-implement and cost-effective approach for laser pulse contrast enhancement, based on the ${\chi}^{(3)}$ nonlinear self-focus

Here we report on a simple-to-implement and cost-effective approach for laser pulse contrast enhancement, based on the ${\chi}^{(3)}$ nonlinear self-focusing effect. An intentionally induced and gently controlled self-focusing in a thin glass transforms the time-dependent intensity into variation in beam divergence. Followed by a spatial discriminating filter, only the strongly focused fraction traverses the setup, at the expense of efficiency. A numerical model, accounting for the pulse and material parameters via a Gaussian ABCD matrix, provides an estimate for the instantaneous beam waist and transmission efficiency, which enables us to evaluate the resulting contrast enhancement. The estimated contrast enhancement spans between 0.5 and 2.5 orders of magnitude, in conjunction with approximately 25%–90% estimated efficiency, depending on the pulse parameters. In a preliminary experiment we demonstrated the effect with 10s-μJ sub GW regime with approximately 40 $\%$ efficiency and a contrast improvement of more than or equal to 20 dB.show less

  • Apr.18,2024
  • High Power Laser Science and Engineering,Vol. 12, Issue 2
  • 02000e18 (2024)
Integrated coherent beam combining system for orbital-angular-momentum shift-keying-based free-space optical links

Orbital-angular-momentum (OAM) multiplexing technology offers a significant dimension to enlarge communication capacity in free-space optical links. The c

Orbital-angular-momentum (OAM) multiplexing technology offers a significant dimension to enlarge communication capacity in free-space optical links. The coherent beam combining (CBC) system can simultaneously realize OAM multiplexing and achieve high-power laser output, providing substantial advantages for long-distance communication. Herein, we present an integrated CBC system for free-space optical links based on OAM multiplexing and demultiplexing technologies for the first time, to the best of our knowledge. A method to achieve flexible OAM multiplexing and efficient demultiplexing based on the CBC system is proposed and demonstrated both theoretically and experimentally. The experimental results exhibit a low bit error rate of 0.47% and a high recognition precision of 98.58% throughout the entire data transmission process. By employing such an ingenious strategy, this work holds promising prospects for enriching ultra-long-distance structured light communication in the future.show less

  • Apr.18,2024
  • Advanced Photonics Nexus,Vol. 3, Issue 3
  • 036003 (2024)
Target-adaptive optical phased array lidar

Lidar based on the optical phased array (OPA) and frequency-modulated continuous wave (FMCW) technology stands out in automotive applications due to its a

Lidar based on the optical phased array (OPA) and frequency-modulated continuous wave (FMCW) technology stands out in automotive applications due to its all-solid-state design, high reliability, and remarkable resistance to interference. However, while FMCW coherent detection enhances the interference resistance capabilities, it concurrently results in a significant increase in depth computation, becoming a primary constraint for improving point cloud density in such perception systems. To address this challenge, this study introduces a lidar solution leveraging the flexible scanning characteristics of OPA. The proposed system categorizes target types within the scene based on RGB images. Subsequently, it performs scans with varying angular resolutions depending on the importance of the targets. Experimental results demonstrate that, compared to traditional scanning methods, the target-adaptive method based on semantic segmentation reduces the number of points to about one-quarter while maintaining the resolution of the primary target area. Conversely, with a similar number of points, the proposed approach increases the point cloud density of the primary target area by about four times.show less

  • Apr.18,2024
  • Photonics Research,Vol. 12, Issue 5
  • 904 (2024)
Feature-enhanced fiber bundle imaging based on light field acquisition

Optical fiber bundles frequently serve as crucial components in flexible miniature endoscopes, transmitting end-to-end images directly for medical and ind

Optical fiber bundles frequently serve as crucial components in flexible miniature endoscopes, transmitting end-to-end images directly for medical and industrial applications. Each core usually acts as a single pixel, and the resolution of the image is limited by the core size and core spacing. We propose a method that exploits the hidden information embedded in the pattern within each core to break the limitation and obtain high-dimensional light field information and more features of the original image including edges, texture, and color. Intra-core patterns are mainly related to the spatial angle of captured light rays and the shape of the core. A convolutional neural network is used to accelerate the extraction of in-core features containing the light field information of the whole scene, achieve the transformation of in-core features to real details, and enhance invisible texture features and image colorization of fiber bundle images.show less

  • Apr.18,2024
  • Advanced Imaging,Vol. 1, Issue 1
  • 011002 (2024)
Advanced Photonics Photonics Insights

The single-photon sensitivity and picosecond time resolution of single-photon light detection and ranging (LiDAR) can provide full-waveform profile for retrieving 3D profile of the target separa

The single-photon sensitivity and picosecond time resolution of single-photon light detection and ranging (LiDAR) can provide full-waveform profile for retrieving 3D profile of the target separated from foreground clutter. This capability has made single-photon LiDAR as a solution for imaging through obscurant, camouflage nets and semitransparent materials. However, the obstructive presence of the clutter and limited pixel number of single-photon detector arrays still pose challenges in achieving high-quality imaging. Here, we demonstrate a single-photon array LiDAR system combined with tailored computational algorithms for high-resolution 3D imaging through camouflage nets. For static targets, we develop a 3D sub-voxel scanning approach along with a photon-efficient deconvolution algorithm. Using this approach, we demonstrate 3D imaging through camouflage nets with a 3x improvement in spatial resolution and a 7.5x improvement in depth resolution. For moving targets, we propose a motion compensation algorithm to mitigate the net's obstructive effects, achieving video-rate imaging of camouflaged scenes at 20 frames per second. More importantly, we demonstrate 3D imaging for complex scenes in various outdoor scenarios and evaluate the advanced features of single-photon LiDAR over both visible-light camera and mid-wave infrared (MWIR) camera. The results point a way forward for high-resolution real-time 3D imaging of multi-depth scenarios.show less

  • Apr.18,2024
  • Advanced Imaging

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 (mirrorli

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 utilizing a common-path illumination strategy, wherein illumination and observation beams are precisely aligned, this method effectively doubles the optical path difference, leading to a twofold increase in measurement sensitivity. In addition, this method mitigates the effects of speckle noise on the measurement of minor deformations, expanding the applications of ESPI. Theoretical and experimental evaluations corroborate the efficacy of this approach.show less

  • Apr.18,2024
  • Chinese Optics Letters,Vol. 22, Issue 8
  • (2024)

We report on a compact, high efficiency mid-infrared continuous-wave (CW) Fe:ZnSe laser pumped by a 2.9 μm fiber laser under liquid nitrogen cooling. A maximum output power of 5.5 W and a slope

We report on a compact, high efficiency mid-infrared continuous-wave (CW) Fe:ZnSe laser pumped by a 2.9 μm fiber laser under liquid nitrogen cooling. A maximum output power of 5.5 W and a slope efficiency of up to 66.3% with respect to the launched pump power were obtained. The overall optical-to-optical (OTO) conversion efficiency, calculated from the output of 2.9 μm fiber laser to the 4-µm laser, was as high as ~54.5%. The OTO efficiency and the slope efficiency are, to the best of our knowledge, the highest in ever reported Fe:ZnSe lasers. A rate-equation-based numerical model of CW operation was established, and the simulation agreed well with the experiment, identifying the routes used in the experiment for such high efficiency.show less

  • Apr.18,2024
  • Chinese Optics Letters,Vol. 22, Issue 8
  • (2024)

In this manuscript, an auto-focusing method in optical scanning holography (OSH) system is proposed. By introducing Lissajous scanning into multiple signal classification (MUSIC) method in time

In this manuscript, an auto-focusing method in optical scanning holography (OSH) system is proposed. By introducing Lissajous scanning into multiple signal classification (MUSIC) method in time reversal (TR) OSH, the axial locations of the targets can be retrieved with better resolution. The feasibility of this method is confirmed by simulation as well as experiment.show less

  • Apr.18,2024
  • Chinese Optics Letters,Vol. 22, Issue 8
  • (2024)