Journals >Advanced Photonics Nexus
Contents
2023
Volume: 2 Issue 5
11 Article(s)
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Editorials
Advanced Photonics Nexus: an excellent kickoff
Xiao-Cong (Larry) Yuan, Anatoly Zayats, and Weibiao Chen
The editorial provides a retrospective glance at the first six months of publication, with a bright forecast for the year ahead.The editorial provides a retrospective glance at the first six months of publication, with a bright forecast for the year ahead..
Advanced Photonics Nexus
- Publication Date: Oct. 19, 2023
- Vol. 2, Issue 5, 050101 (2023)
Reviews
Recent advances in deep-learning-enhanced photoacoustic imaging | Author Presentation
Jinge Yang, Seongwook Choi, Jiwoong Kim, Byullee Park, and Chulhong Kim
Photoacoustic imaging (PAI), recognized as a promising biomedical imaging modality for preclinical and clinical studies, uniquely combines the...show more
Photoacoustic imaging (PAI), recognized as a promising biomedical imaging modality for preclinical and clinical studies, uniquely combines the advantages of optical and ultrasound imaging. Despite PAI’s great potential to provide valuable biological information, its wide application has been hindered by technical limitations, such as hardware restrictions or lack of the biometric information required for image reconstruction. We first analyze the limitations of PAI and categorize them by seven key challenges: limited detection, low-dosage light delivery, inaccurate quantification, limited numerical reconstruction, tissue heterogeneity, imperfect image segmentation/classification, and others. Then, because deep learning (DL) has increasingly demonstrated its ability to overcome the physical limitations of imaging modalities, we review DL studies from the past five years that address each of the seven challenges in PAI. Finally, we discuss the promise of future research directions in DL-enhanced PAI.
.Advanced Photonics Nexus
- Publication Date: Jul. 24, 2023
- Vol. 2, Issue 5, 054001 (2023)
Research Articles
Achieving higher photoabsorption than group III-V semiconductors in ultrafast thin silicon photodetectors with integrated photon-trapping surface structures | On the Cover , Author Presentation
Wayesh Qarony, Ahmed S. Mayet, Ekaterina Ponizovskaya Devine, Soroush Ghandiparsi... and M. Saif Islam|Show fewer author(s)
The photosensitivity of silicon is inherently very low in the visible electromagnetic spectrum, and it drops rapidly beyond 800 nm in near-infrared...show more
The photosensitivity of silicon is inherently very low in the visible electromagnetic spectrum, and it drops rapidly beyond 800 nm in near-infrared wavelengths. We have experimentally demonstrated a technique utilizing photon-trapping surface structures to show a prodigious improvement of photoabsorption in 1-μm-thin silicon, surpassing the inherent absorption efficiency of gallium arsenide for a broad spectrum. The photon-trapping structures allow the bending of normally incident light by almost 90 deg to transform into laterally propagating modes along the silicon plane. Consequently, the propagation length of light increases, contributing to more than one order of magnitude improvement in absorption efficiency in photodetectors. This high-absorption phenomenon is explained by finite-difference time-domain analysis, where we show an enhanced photon density of states while substantially reducing the optical group velocity of light compared to silicon without photon-trapping structures, leading to significantly enhanced light–matter interactions. Our simulations also predict an enhanced absorption efficiency of photodetectors designed using 30- and 100-nm silicon thin films that are compatible with CMOS electronics. Despite a very thin absorption layer, such photon-trapping structures can enable high-efficiency and high-speed photodetectors needed in ultrafast computer networks, data communication, and imaging systems, with the potential to revolutionize on-chip logic and optoelectronic integration.
.Advanced Photonics Nexus
- Publication Date: Jul. 24, 2023
- Vol. 2, Issue 5, 056001 (2023)
Differentiated design strategies toward broadband achromatic and polarization-insensitive metalenses | Editors' Pick
Ximin Tian, Yafeng Huang, Junwei Xu, Tao Jiang... and Zhi-Yuan Li|Show fewer author(s)
Metasurfaces have emerged as a flexible platform for shaping the electromagnetic field via the tailoring phase, amplitude, and...show moreMetasurfaces have emerged as a flexible platform for shaping the electromagnetic field via the tailoring phase, amplitude, and polarization at will. However, the chromatic aberration inherited from building blocks’ diffractive nature plagues them when used in many practical applications. Current solutions for eliminating chromatic aberration usually rely on searching through many meta-atoms to seek designs that satisfy both phase and phase dispersion preconditions, inevitably leading to intensive design efforts. Moreover, most schemes are commonly valid for incidence with a specific spin state. Here, inspired by the Rayleigh criterion for spot resolution, we present a design principle for broadband achromatic and polarization-insensitive metalenses using two sets of anisotropic nanofins based on phase change material Ge2Sb2Se4Te1. By limiting the rotation angles of all nanofins to either 0 deg or 90 deg, the metalens with a suitable numerical aperture constructed by this fashion allows for achromatic and polarization-insensitive performance across the wavelength range of 4–5 μm, while maintaining high focusing efficiency and diffraction-limited performance. We also demonstrate the versatility of our approach by successfully implementing the generation of broadband achromatic and polarization-insensitive focusing optical vortex. This work represents a major advance in achromatic metalenses and may find more applications in compact and chip-scale devices..
Advanced Photonics Nexus
- Publication Date: Jul. 22, 2023
- Vol. 2, Issue 5, 056002 (2023)
Achromatic on-chip focusing of graphene plasmons for spatial inversions of broadband digital optical signals
Zhiyong Wu, and Zhengji Xu
On-chip focusing of plasmons in graded-index lenses is important for imaging, lithography, signal processing, and optical interconnects at the...show moreOn-chip focusing of plasmons in graded-index lenses is important for imaging, lithography, signal processing, and optical interconnects at the deep subwavelength nanoscale. However, owing to the inherent strong wavelength dispersion of plasmonic materials, the on-chip focusing of plasmons suffers from severe chromatic aberrations. With the well-established planar dielectric grating, a graded-index waveguide array lens (GIWAL) is proposed to support the excitation and propagation of acoustic graphene plasmon polaritons (AGPPs) and to achieve the achromatic on-chip focusing of the AGPPs with a focus as small as about 2% of the operating wavelength in the frequency band from 10 to 20 THz, benefiting from the wavelength-independent index profile of the GIWAL. An analytical theory is provided to understand the on-chip focusing of the AGPPs and other beam evolution behaviors, such as self-focusing, self-collimation, and pendulum effects of Gaussian beams as well as spatial inversions of digital optical signals. Furthermore, the possibility of the GIWAL to invert spatially broadband digital optical signals is demonstrated, indicating the potential value of the GIWAL in broadband digital communication and signal processing..
Advanced Photonics Nexus
- Publication Date: Jul. 24, 2023
- Vol. 2, Issue 5, 056003 (2023)
Operation of multiphonon-assisted laser in the nanosecond time scales
Huichen Si, Fei Liang, Dazhi Lu, Haohai Yu... and Yicheng Wu|Show fewer author(s)
Electron–phonon coupling can tailor electronic transition processes and result in direct lasing far beyond the fluorescence spectrum....show moreElectron–phonon coupling can tailor electronic transition processes and result in direct lasing far beyond the fluorescence spectrum. The applicable time scales of these kinds of multiphonon-assisted lasers determine their scientific boundaries and further developments, since the response speed of lattice vibrations is much slower than that of electrons. At present, the temporal dynamic behavior of multiphonon-assisted lasers has not yet been explored. Herein, we investigate the Q-switched laser performance of ytterbium-doped
Advanced Photonics Nexus
- Publication Date: Jul. 31, 2023
- Vol. 2, Issue 5, 056004 (2023)
Generation of biaxially accelerating static Airy light-sheets with 3D-printed freeform micro-optics
Yanis Taege, Tim Samuel Winter, Sophia Laura Schulz, Bernhard Messerschmidt, and Çağlar Ataman
One-dimensional Airy beams allow the generation of thin light-sheets without scanning, simplifying the complex optical arrangements of...show moreOne-dimensional Airy beams allow the generation of thin light-sheets without scanning, simplifying the complex optical arrangements of light-sheet microscopes (LSMs) with an extended field of view (FOV). However, their uniaxial acceleration limits the maximum numerical aperture of the detection objective in order to keep both the active and inactive axes within the depth of field. This problem is particularly pronounced in miniaturized LSM implementations, such as those for endomicroscopy or multi-photon neural imaging in freely moving animals using head-mounted miniscopes. We propose a new method to generate a static Airy light-sheet with biaxial acceleration, based on a novel phase profile. This light-sheet has the geometry of a spherical shell whose radius of curvature can be designed to match the field curvature of the micro-objective. We present an analytical model for the analysis of the light-sheet parameters and verify it by numerical simulations in the paraxial regime. We also discuss a micro-optical experimental implementation combining gradient-index optics with a 3D-nanoprinted, fully refractive phase plate. The results confirm that we are able to match detection curvatures with radii in the range of 1.5 to 2 mm..
Advanced Photonics Nexus
- Publication Date: Aug. 01, 2023
- Vol. 2, Issue 5, 056005 (2023)
Highly sensitive miniature needle PVDF-TrFE ultrasound sensor for optoacoustic microscopy
Yu-Hang Liu, Alexey Kurnikov, Weiye Li, Pavel Subochev, and Daniel Razansky
A wideband sensitive needle ultrasound sensor based on a polarized PVDF-TrFE copolymer piezoelectric film has been developed, which is...show moreA wideband sensitive needle ultrasound sensor based on a polarized PVDF-TrFE copolymer piezoelectric film has been developed, which is capable of providing a noise equivalent pressure of 14 Pa and a uniform frequency response ranging from 1 to 25 MHz. Its high sensitivity (1.6 μV / Pa) and compact size were achieved by capitalizing on the large electromechanical coupling coefficient of PVDF-TrFE and minimizing parasitic capacitance in a two-stage amplifier structure. The detection sensitivity of the newly designed sensor outperformed commercially available hydrophones with an equivalent sensing element area by a factor of 9. The sensor has been successfully integrated into a light scanning optoacoustic microscopy (OAM) system with a limited working space. Submicrometer resolution images were subsequently attained from living mice without employing signal averaging. The miniature sensor design can readily be integrated into various OAM systems and further facilitate multimodal imaging system implementations..
Advanced Photonics Nexus
- Publication Date: Aug. 16, 2023
- Vol. 2, Issue 5, 056006 (2023)
Efficient reference-less transmission matrix retrieval for a multimode fiber using fast Fourier transform
Jingshan Zhong, Zhong Wen, Quanzhi Li, Qilin Deng, and Qing Yang
Imaging through multimode fiber (MMF) provides high-resolution imaging through a fiber with cross section down to tens of micrometers...show moreImaging through multimode fiber (MMF) provides high-resolution imaging through a fiber with cross section down to tens of micrometers. It requires interferometry to measure the full transmission matrix (TM), leading to the drawbacks of complicated experimental setup and phase instability. Reference-less TM retrieval is a promising robust solution that avoids interferometry, since it recovers the TM from intensity-only measurements. However, the long computational time and failure of 3D focusing still limit its application in MMF imaging. We propose an efficient reference-less TM retrieval method by developing a nonlinear optimization algorithm based on fast Fourier transform (FFT). Furthermore, we develop an algorithm to correct the phase offset error of retrieved TM using defocused intensity images and hence achieve 3D focusing. The proposed method is validated by both simulations and experiments. The FFT-based TM retrieval algorithm achieves orders of magnitude of speedup in computational time and recovers 2286 × 8192 TM of a 0.22 NA and 50 μm diameter MMF with 112.9 s by a computer of 32 CPU cores. With the advantages of efficiency and correction of phase offset, our method paves the way for the application of reference-less TM retrieval in not only MMF imaging but also broader applications requiring TM calibration..
Advanced Photonics Nexus
- Publication Date: Sep. 12, 2023
- Vol. 2, Issue 5, 056007 (2023)
High-fidelity SIM reconstruction-based super-resolution quantitative FRET imaging
Zewei Luo, Guodong Zang, Ge Wu, Mengting Kong... and Tongsheng Chen|Show fewer author(s)
Structured illumination-based super-resolution Förster resonance energy transfer microscopy (SIM-FRET) provides an approach to...show moreStructured illumination-based super-resolution Förster resonance energy transfer microscopy (SIM-FRET) provides an approach to resolving molecular behavior localized in intricate biological structures in living cells. However, SIM reconstruction artifacts will decrease the quantitative analysis fidelity of SIM-FRET signals. To address these issues, we have developed a method called HiFi spectrum optimization SIM-FRET (HiFi-SO-SIM-FRET), which uses optimized Wiener parameters in the two-step spectrum optimization to suppress sidelobe artifacts and achieve super-resolution quantitative SIM-FRET. We validated our method by demonstrating its ability to reduce reconstruction artifacts while maintaining the accuracy of FRET signals in both simulated FRET models and live-cell FRET-standard construct samples. In summary, HiFi-SO-SIM-FRET provides a promising solution for achieving high spatial resolution and reducing SIM reconstruction artifacts in quantitative FRET imaging..
Advanced Photonics Nexus
- Publication Date: Sep. 13, 2023
- Vol. 2, Issue 5, 056008 (2023)
High repetition rate ultrafast laser-structured nickel electrocatalyst for efficient hydrogen evolution reaction
Zaiwei Cai, Zihao Li, Yingtao Zhang, Chiyi Wei... and Zhongmin Yang|Show fewer author(s)
Laser processing with high-power ultrashort pulses, which promises high precision and efficiency, is an emerging new tool for material...show moreLaser processing with high-power ultrashort pulses, which promises high precision and efficiency, is an emerging new tool for material structuring. High repetition rate ultrafast laser highlighting with a higher degree of freedom in its burst mode is believed to be able to create micro/nanostructures with even more variety, which is promising for electrochemical applications. We employ a homemade high repetition rate ultrafast fiber laser for structuring metal nickel (Ni) and thus preparing electrocatalysts for hydrogen evolution reaction (HER) for the first time, we believe. Different processing parameters are designed to create three groups of samples with different micro/nanostructures. The various micro/nanostructures not only increase the surface area of the Ni electrode but also regulate local electric field and help discharge hydrogen bubbles, which offer more favorable conditions for HER. All groups of the laser-structured Ni exhibit enhanced electrocatalytic activity for HER in the alkaline solution. Electrochemical measurements demonstrate that the overpotential at 10 mA cm - 2 can be decreased as much as 182 mV compared with the overpotential of the untreated Ni (-457 mV versus RHE)..
Advanced Photonics Nexus
- Publication Date: Sep. 21, 2023
- Vol. 2, Issue 5, 056009 (2023)
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