-
LMA fibers with increased higher-order mode loss for high average power, pulsed, diffraction-limited lasers Opt. Express (IF 3.8) Pub Date : 2024-04-22 Yaakov Glick, Jose Pincha, Ishu Kansal, Robert Windeler, Vasiliy Lukonin, Eric Monberg, Erin S. Lamb, Lalitkumar Bansal, and Jeffrey W. Nicholson
We demonstrate new, large-mode area (LMA) gain fibers with ∼25 µm mode-field diameter, and increased higher-order mode loss that enable diffraction limited, pulsed fiber lasers operating at high average power with high pulse energy. We achieved 1.6 mJ, ns pulses, with 1.2 kW average power and 370 kW peak power in one of the new Yb-doped gain fibers. In a second, higher absorption fiber, we demonstrate
-
Scene-based dual domain non-uniformity correction algorithm for stripe and optics-caused fixed pattern noise removal Opt. Express (IF 3.8) Pub Date : 2024-04-22 Yuan Liu, Bingwen Qiu, Yayuan Tian, Juan Cai, Xiubao Sui, and Qian Chen
Non-uniformity is a long-standing problem that significantly degrades infrared images through fixed pattern noise (FPN). Existing scene-based algorithms for non-uniformity correction (NUC) effectively eliminate stripe FPN assuming consistent inter-frame non-uniformity. However, they are ineffective in handling spatially continuous optical FPN. In this paper, a scene-based dual domain correction approach
-
Equalization of RGB coupling efficiencies of metasurface waveguide coupler by adjusting imaginary part of refractive index Opt. Express (IF 3.8) Pub Date : 2024-04-22 Ruqing Duan, Diyang Gu, Chenhui Liang, Lele Xia, Hang Chen, Yuan Chen, and Liu Yang
Optical metasurfaces offer high-efficiency and flexible wavefront shaping for near-eye displays, especially in wideband waveguide couplers accommodating RGB primary colors. By leveraging the resonance characteristics of sub-wavelength periodic nanostructures, metasurfaces surpass the limitations of traditional optics that rely on multiple components and mediums. In this study, we propose adjustment
-
Noise correction in differential phase contrast for improving phase sensitivity Opt. Express (IF 3.8) Pub Date : 2024-04-22 Hu Liu, Jialin Liu, Wei Zhou, Baoteng Xu, Zengqi Yue, Daxi Xiong, and Xibin Yang
Differential phase contrast (DPC) imaging relies on computational analysis to extract quantitative phase information from phase gradient images. However, even modest noise level can introduce errors that propagate through the computational process, degrading the quality of the final phase result and further reducing phase sensitivity. Here, we introduce the noise-corrected DPC (ncDPC) to enhance phase
-
Human activity recognition using a single-photon direct time-of-flight sensor Opt. Express (IF 3.8) Pub Date : 2024-04-22 Germán Mora-Martín, Stirling Scholes, Robert K. Henderson, Jonathan Leach, and Istvan Gyongy
Single-Photon Avalanche Diode (SPAD) direct Time-of-Flight (dToF) sensors provide depth imaging over long distances, enabling the detection of objects even in the absence of contrast in colour or texture. However, distant objects are represented by just a few pixels and are subject to noise from solar interference, limiting the applicability of existing computer vision techniques for high-level scene
-
Sub-pixel target fine spatial feature extraction method based on aperture coding and micro-scanning imaging mechanism Opt. Express (IF 3.8) Pub Date : 2024-04-22 Chao Zhang, Ying yuan, Xiaorui Wang, Yang Ning, Yue Li, and Yangyang Li
The small imaging size of targets over long distances results in the loss of geometry and spatial features. Current methods are subject to sampling limitations and cannot accurately capture the spatial features of sub-pixel targets. This paper proposes a method to accurately locate and extract the fine spatial features of sub-pixel targets through aperture coding and micro-scanning imaging. First,
-
Broadband silicon nitride integrated polarization rotators at 780 nm Opt. Express (IF 3.8) Pub Date : 2024-04-22 Marcel W. Pruessner, Kyle J. Walsh, Nathan F. Tyndall, Nicholas M. Fahrenkopf, Alin O. Antohe, and Todd H. Stievater
Polarization management, and in particular polarization rotation, is becoming increasingly important for photonic integrated circuits (PICs). While fiber-optic networks are generally polarization insensitive, the large aspect ratio of high-index-contrast PIC waveguides leads to a large polarization-dependent response of integrated components such as waveguides, optical cavities, couplers, etc. Although
-
Relations between near-field enhancements and Purcell factors in hybrid nanostructures of plasmonic antennas and dielectric cavities Opt. Express (IF 3.8) Pub Date : 2024-04-22 Xu-Tao Tang, Lin Ma, Yue You, Xiao-Jing Du, Hua Qiu, Xi-Hua Guan, Jun He, and Zhong-Jian Yang
Strong near-field enhancements (NFEs) of nanophotonic structures are believed to be closely related to high Purcell factors (FP). Here, we theoretically show that the correlation is partially correct; the extinction cross section (σ) response is also critical in determining FP. The divergence between NFE and FP is especially pronounced in plasmonic-dielectric hybrid systems, where the plasmonic antenna
-
Encoding independent wavefronts in a single metasurface for high-order optical vortex recognition Opt. Express (IF 3.8) Pub Date : 2024-04-22 Kai He, Tigang Ning, Jing Li, Jingjing Zheng, Li Pei, and Jianshuai Wang
The orbital angular momentum (OAM) of vortex beams has great potential in optical communications due to its communication confidentiality and low crosstalk. It is necessary to design a plausible OAM pattern recognition mechanism. Abandoning AI models that require large datasets, a single passive all-dielectric metasurface consisting of TiO2 nanopillars on a SiO2 substrate is used to recognize high-order
-
Fiber Bragg gratings fabricated in fibers with different geometries by femtosecond laser written through the coating and their applications in strain sensing and fiber laser Opt. Express (IF 3.8) Pub Date : 2024-04-22 Yingjie Li, Tao Chen, Jinhai Si, Zenghui Sun, Ruidong Lv, Daqi Zhang, Bo Gao, and Xun Hou
Applications of the type-I fiber Bragg gratings (FBGs) written through the coating (TTC) in strain sensing and tunable distributed Bragg reflector (DBR) fiber lasers were demonstrated. We reported the principle of selecting the distance between the fiber and the phase mask when writing type-I TTC FBGs. Type-I TTC FBGs written in commercially available acrylate-coated fibers with various geometries
-
Broadband nonlinear conversion and random quasi-phase-matching in transparent glass composite Opt. Express (IF 3.8) Pub Date : 2024-04-22 Jinwei Cao, Yipeng Lun, Xingzhao Huang, Siyun Li, Rongtai Lu, Meihui Zhang, Xu Lu, M. Sun, Huakang Yu, and Q. Qian
With the development of laser technology, nonlinear optics plays a crucial role in frequency conversion. However, the generation of second harmonics in nonlinear optical crystals is generally subject to rigorous phase-matching conditions that hinder the performance of broadband tunability. It is believed that introducing disorders in nonlinear optical materials is helpful to overcome this obstacle
-
Nonlinear dynamics of an interband cascade laser with optical injection Opt. Express (IF 3.8) Pub Date : 2024-04-22 Kai-Li Lin, Peng-Lei Wang, Yi-Bo Peng, Yu Deng, and Cheng Wang
This work reports the nonlinear dynamics of a mid-infrared interband cascade laser (ICL) subject to optical injection. It is shown that the stable locking regime is asymmetric and broadens with increasing injection strength. Outside the locking regime, the ICL mostly produces period-one oscillations. However, three categories of periodic pulse oscillations are observed in the vicinity of the Hopf bifurcation
-
Inelastic two-wave mixing induced high-efficiency transfer of optical vortices Opt. Express (IF 3.8) Pub Date : 2024-04-22 Xu Deng, Tao Shui, and Wen-Xing Yang
A scheme for high-efficiency transfer of optical vortices is proposed by an inelastic two-wave mixing (ITWM) process in an inverted-Y four-level atomic medium, which is originally prepared in a coherent superposition of two ground states. The orbital angular momentum (OAM) information in the incident vortex probe field can be transferred to the generated signal field through the ITWM process. Choosing
-
Deep learning-assisted inverse design of nanoparticle-embedded radiative coolers Opt. Express (IF 3.8) Pub Date : 2024-04-18 Min Ju Kim, June Tae Kim, Mi Jin Hong, Sang Wook Park, and Gil Ju Lee
Radiative cooling is an energy-efficient technology without consuming power. Depending on their use, radiative coolers (RCs) can be designed to be either solar-transparent or solar-opaque, which requires complex spectral characteristics. Our research introduces a novel deep learning-based inverse design methodology for creating thin-film type RCs. Our deep learning algorithm determines the optimal
-
Long-term monitoring chlorophyll-a concentration using HJ-1 A/B imagery and machine learning algorithms in typical lakes, a cold semi-arid region Opt. Express (IF 3.8) Pub Date : 2024-04-18 Jianhua Ren, Haoyun Zhou, Zui Tao, Liu Ge, Kaishan Song, Shiqi Xu, Yong Li, Lele Zhang, Xiyu Zhang, and Sijia Li
Chlorophyll a (Chl-a) in lakes serves as an effective marker for assessing algal biomass and the nutritional level of lakes, and its observation is feasible through remote sensing methods. HJ-1 (Huanjing-1) satellite, deployed in 2008, incorporates a CCD capable of a 30 m resolution and has a revisit interval of 2 days, rendering it a superb choice or supplemental sensor for monitoring trophic state
-
Effect of turbulence-induced sediment resuspension and sedimentation on underwater wireless optical communication Opt. Express (IF 3.8) Pub Date : 2024-04-18 Hexiang Yuan, Meiwei Kong, Mengqi Wang, Wenxin Cui, Yanyan Pan, Hui Zhou, and Qunhui Yang
In real-life marine environments, the composition and grain size of suspended sediments and the resuspension and sedimentation of sediments caused by turbulence may have a significant impact on underwater wireless optical communication (UWOC). However, to date, researchers have not conducted quantitative research on this issue. To this end, we innovatively study the effects of different compositions
-
Enhanced imaging with binary circular Dammann Fresnel zone plate Opt. Express (IF 3.8) Pub Date : 2024-04-18 Stefan R. Anton, Nadav Shabairou, Stefan G. Stanciu, George A. Stanciu, and Zeev Zalevsky
We introduce a novel approach in optical engineering by combining Dammann gratings with binary Fresnel zone plates to create a unique hybrid optical element with enhanced energetic efficiency of its focal spots. Traditionally, binary Fresnel zone plates focus light at multiple points with varying intensities, while Dammann gratings are renowned for their efficient and uniform light splitting capabilities
-
Optical spatial differentiation enabled layer sensing of two-dimensional atomic crystals Opt. Express (IF 3.8) Pub Date : 2024-04-19 Jin Zhang, Hanqing Wu, Mian Huang, Xin Dai, Tao Zhang, Yingdan Li, and Xiaoyan Yu
Zero-thickness model and slab model are two important models in the description of optical behaviors in two-dimensional atomic crystals. The predicted difference in optical behaviors between the two models is very small, which is difficult to distinguish by established measurement methods. Here, we present an optical spatial differentiation method to examine the difference in edge images of different
-
Surrogate gradient learning in spiking networks trained on event-based cytometry dataset Opt. Express (IF 3.8) Pub Date : 2024-04-18 Muhammed Gouda, Steven Abreu, and Peter Bienstman
Spiking neural networks (SNNs) are bio-inspired neural networks that - to an extent - mimic the workings of our brains. In a similar fashion, event-based vision sensors try to replicate a biological eye as closely as possible. In this work, we integrate both technologies for the purpose of classifying micro-particles in the context of label-free flow cytometry. We follow up on our previous work in
-
Unsupervised reconstruction with a registered time-unsheared image constraint for compressed ultrafast photography Opt. Express (IF 3.8) Pub Date : 2024-04-18 Haoyu Zhou, Yan Song, Zhiming Yao, Dongwei Hei, Yang Li, Baojun Duan, Yinong Liu, and Liang Sheng
Compressed ultrafast photography (CUP) is a computational imaging technology capable of capturing transient scenes in picosecond scale with a sequence depth of hundreds of frames. Since the inverse problem of CUP is an ill-posed problem, it is challenging to further improve the reconstruction quality under the condition of high noise level and compression ratio. In addition, there are many articles
-
Programmable photoacoustic manipulation of microparticles in liquid Opt. Express (IF 3.8) Pub Date : 2024-04-18 Jinzhi Li, Xichuan Zhao, Ruoqin Zhang, Di Zhou, Feng Li, Zhiyuan Li, and Honglian Guo
Particle manipulation through the transfer of light or sound momentum has emerged as a powerful technique with immense potential in various fields, including cell biology, microparticle assembly, and lab-on-chip technology. Here, we present a novel method called Programmable Photoacoustic Manipulation (PPAM) of microparticles in liquid, which enables rapid and precise arrangement and controllable transport
-
Design of AR system tracking registration method using dynamic target light-field Opt. Express (IF 3.8) Pub Date : 2024-04-18 Zhe An, Yang Liu, and Mingyu Xue
In the process of tracking registration for an augmented reality (AR) system, it's essential first to obtain the system's initial state, as its accuracy significantly influences the precision of subsequent three-dimensional tracking registration. At this point, minor movements of the target can directly lead to calibration errors. Current methods fail to address the challenge of capturing the initial
-
Stitching interferometry using alternating calibration of positioning and systematic errors Opt. Express (IF 3.8) Pub Date : 2024-04-18 Yi Zong, Caiyun Yu, Weijian Liu, Yixuan Liu, Yongshen Zhong, Huitong Huang, Mingliang Duan, and Jianxin Li
Stitching interferometry is an essential technique for the non-contact, high-precision measurement of large apertures or complex optical surfaces. However, the accuracy of full-aperture surface reconstruction is significantly compromised by subaperture positioning and systematic errors. To address this challenge, this study introduces a novel stitching interferometry method utilizing alternating calibration
-
Polynomial expansion method for full wave three-dimensional analysis of dielectric waveguides and periodic structures Opt. Express (IF 3.8) Pub Date : 2024-04-17 Kamalodin Arik and Mahmood Akbari
In summary, the utilization of Legendre polynomial expansion in the modal analysis of stratified dielectric layers with doubly periodic permittivity profiles offers a departure from conventional methods. This novel approach, grounded in the analytical projection of Maxwell’s equations onto the Hilbert space defined by Legendre polynomials, results in well-behaved algebraic equations. These equations
-
Optical mode manipulation using deep spatial diffractive neural networks Opt. Express (IF 3.8) Pub Date : 2024-04-18 Zhengsen Ruan, Bowen Wang, Jinlong Zhang, Han Cao, Ming Yang, Wenrui Ma, Xun Wang, Yu Zhang, and Jian Wang
In this paper, we investigate the theoretical models and potential applications of spatial diffractive neural network (SDNN) structures, with a particular focus on mode manipulation. Our research introduces a novel diffractive transmission simulation method that employs matrix multiplication, alongside a parameter optimization algorithm based on neural network gradient descent. This approach facilitates
-
Ultrafast evanescently coupled waveguide MUTC-PDs with high responsivity Opt. Express (IF 3.8) Pub Date : 2024-04-18 Mingwei Sun, Bing Xiong, Changzheng Sun, Zhibiao Hao, Jian Wang, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, and Yi Luo
Novel evanescently coupled waveguide modified uni-traveling carrier photodiodes (MUTC-PDs) employing a thick multi-layer coupling waveguide are reported. To improve the optical-to-electrical (O/E) conversion efficiency, a thick multi-layer coupling waveguide with a gradually increased refractive index from the bottom layer to the absorption layer is utilized. The refractive index profile facilitates
-
Modifying single-crystal silicon and trimming silicon microring devices by femtosecond laser irradiation Opt. Express (IF 3.8) Pub Date : 2024-04-18 Jia Du, Libing Zhou, Weixiao Xu, Yuanan Zhao, MingZhe Chen, BoYu Zhang, and Weibiao Chen
Single-crystal silicon (c-Si) is a vital component of photonic devices and has obvious advantages. Moreover, femtosecond-pulsed laser interactions with matter have been widely applied in micro/nanoscale processing. In this paper, we report the modification mechanisms of c-Si induced by a femtosecond laser (350 fs, 520 nm) at different pulse fluences, along with the mechanism of this technique to trim
-
Evolution mechanism of subsurface damage during laser machining process of fused silica Opt. Express (IF 3.8) Pub Date : 2024-04-18 Yichi Han, Songlin Wan, Xiaocong Peng, Huan Chen, Shengshui Wang, Hanjie Li, Pandeng Jiang, Chaoyang Wei, and Jianda Shao
The machining-induced subsurface damage (SSD) on fused silica optics would incur damage when irradiated by intense lasers, which severely restricts the service life of fused silica optics. The high absorption of fused silica to 10.6 µm makes it possible to utilize pulsed CO2 laser to remove and characterize SSD by layer-by-layer ablation, which improves its laser-induced damage threshold. However,
-
Modeling extended L-band fiber amplifiers using neural networks trained on experimental data Opt. Express (IF 3.8) Pub Date : 2024-04-18 Hamed Rabbani, Saber Jalilpiran, Kaboko Jean-Jacques Monga, Sophie Larochelle, and Leslie A. Rusch
Producing high performance amplifiers requires accurate numerical models. As the optimization space is large, computationally efficient models are of great value. Parameter-based models for L-band amplifiers have accuracy limited by difficulty in estimating the Giles-parameter. The use a neural network model can avoid parametrization. We exploit a rich, experimentally captured training set to achieve
-
Evaluation of the impact of weak end feedback on the SBS threshold in high-power narrow-linewidth fiber amplifiers Opt. Express (IF 3.8) Pub Date : 2024-04-18 Wei Li, Yu Deng, Chen Qi, Yisha Chen, Pengfei Ma, Wei Liu, Zhou Pu, and Lei Si
In this work, we quantitatively investigate the SBS threshold in high-power narrow-linewidth fiber amplifiers seeded with phase-modulated single-frequency lasers in presence of weak end feedback. The impacts of the end feedback and spectral linewidths on the SBS threshold are demonstrated in detail through comparative experiments and numerical simulations, respectively. In the experiment, we have pointed
-
Chiral quasi bound states in the continuum for augmented reality Opt. Express (IF 3.8) Pub Date : 2024-04-17 Qianhui Bi, Run Chen, Xiaofei Ye, Yujuan Peng, Shuming Wang, and Zhenlin Wang
Augmented Reality technology enables users to interact with virtual imagines and the real world. The emergence of AR has propelled the development of the next generation of optical devices towards miniaturization, lightweight design, and enhanced light field manipulation capabilities. However, current AR glass still suffer from shortcomings of low efficiency. This work proposes a near-eye display device
-
Configurable dual-topological-interface-states induced reflection in hybrid multilayers consisting of a Ge2Sb2Te5 film Opt. Express (IF 3.8) Pub Date : 2024-04-18 Zekun Ge, Tian Sang, Chen Luo, Xianghu Zhang, and Chui Pian
Active control of induced reflection is crucial for many potential applications ranging from slowing light to biosensing devices. However, most previous approaches require patterned nanostructures to achieve controllable induced reflection, which hinders their further applications due to complicated architectures. Herein, we propose a lithography-free multilayered structure to achieve the induced reflection
-
Towards high-performance polarimeters with large-area uniform chiral shells: a comparative study on the polarization detection precision enabled by the Mueller matrix and deep learning algorithm Opt. Express (IF 3.8) Pub Date : 2024-04-18 Liangke Ren, Xiu Yang, Shanshan Huang, Zheqiang Zhong, Jialong Peng, Luyao Ye, Yidong Hou, and Bin Zhang
Polarization detection and imaging technologies have attracted significant attention for their extensive applications in remote sensing, biological diagnosis, and beyond. However, previously reported polarimeters heavily relied on polarization-sensitive materials and pre- established mapping relationships between the Stokes parameters and detected light intensities. This dependence, along with fabrication
-
Merging diverse bound states in the continuum: from intrinsic to extrinsic scenarios Opt. Express (IF 3.8) Pub Date : 2024-04-18 Liangliang Liu, Haoqi Luo, Yonghua Lu, and Pei Wang
Bound states in the continuum (BICs) in photonic crystal slabs are characterized as vortex centers in far-field polarization and infinite quality (Q) factors, which can be dynamically manipulated in momentum space to construct the singularity configurations with functionalities such as merging BICs for further suppress scattering loss of nearby resonance. However, the vast majority of research focuses
-
Multipole solitons and vortex solitons in nonlocal nonlinear media Opt. Express (IF 3.8) Pub Date : 2024-04-17 S. F. Wang
The nonlinear Schrödinger equation (NLSE) under nonlocal nonlinear media (NNM) is described and the approximate analytical solutions of the vector multipole solitons and vortex optical soliton clusters are obtained via the variational method. The results show that the structure of the optical solitons is determined by modulation depth and topological charge. In the propagation process, the spatial
-
Conical quasi-phase-matching second harmonic generation in a 2D photonic crystal with hybrid Ewald geometric method Opt. Express (IF 3.8) Pub Date : 2024-04-19 Chang Ping Ren, Huang Huang, and Xu Hao Hong
The direction variation of the fundamental wave in the same nonlinear photonic crystal would cause different pattern of harmonics generation. In a 2D/3D crystal with dense reciprocal lattice vectors, there will be large numbers of conical harmonic beams evolving with direction change of the fundamental wave. By rearranging the Ewald sphere and superposing it into the Ewald shell, we have a hybrid Ewald
-
Optical chaotic communication system based on time-delayed shift keying and common-signal-induced synchronization Opt. Express (IF 3.8) Pub Date : 2024-04-18 Minjun Li, Xuefang Zhou, Fei Wang, Guowei Yang, Meihua Bi, Mengmeng Xu, Miao Hu, and Haozhen Li
Aiming at the difficulty of traditional chaotic-shift-keying (CSK) systems in resisting return map attacks, we propose an optical chaotic communication system based on time-delayed shift keying and common-signal-induced synchronization. This scheme combines amplified spontaneous emission (ASE) noise, phase modulator (PM), and fiber Bragg grating (FBG) to achieve dual masking in both intensity and phase
-
Generalized modulation for distance-aware optical camera communication beyond oversampled and undersampled schemes Opt. Express (IF 3.8) Pub Date : 2024-04-18 Ke Dong, Miaomiao Kong, Weiqiang Su, Siying Ma, and Mingjun Wang
Oversampled modulation (OM) and undersampled modulation (UM) are two commonly used optical camera communication (OCC) modulation schemes for high-speed communication in short-range and reliable communication at long distances, respectively. However, the relationship between these two schemes and the tradeoff in performance for arbitrary communication distances have not been thoroughly investigated
-
Coherent Nyquist optical pulse transmission at nearly 1-Tb/s/λ over 1,600 km with a capacity of 21.5 Tb/s using PS-32 QAM signals Opt. Express (IF 3.8) Pub Date : 2024-04-19 Shohei Beppu, Aoto Ishikawa, Takeki Serikawa, Masato Yoshida, Toshihiko Hirooka, and Masataka Nakazawa
We demonstrate the 1,600-km transmission at nearly 1-Tb/s/λ signals with a capacity of 21.5 Tb/s. Probabilistic shaping was newly applied to high-speed coherent optical Nyquist pulse transmission systems to maximize the transmission capacity. Employing a 160-GBd PS-32 QAM format, WDM signals at nearly 1-Tb/s/λ were successfully transmitted over 1,600 km with a capacity of 21.5 Tb/s.
-
High-order LP modes based Sagnac interference for temperature sensing with an enhanced optical Vernier effect Opt. Express (IF 3.8) Pub Date : 2024-04-17 Hongwei Li, Hailiang Chen, Sajid Ullah, Yuxin Li, Ruyue Shi, Zhigang Gao, Chaoyi Liu, Sa zhang, Shuguang Li, and Sigang Yang
In this paper, high-order LP modes based Sagnac interference for temperature sensing are proposed and investigated theoretically. Based on the specific high-order LP modes excited through the mode selective couplers (MSCs), we design a stress-induced Panda-type few-mode fiber (FMF) supporting 4 LP modes and construct a Sagnac interferometer to achieve a highly sensitive temperature sensor. The performances
-
High Verdet constant of Tb2O3-doped TiO-B2O3-Al2O3-Na2O magneto-optical glass Opt. Express (IF 3.8) Pub Date : 2024-04-18 Jiadong Li, Xudong Zhao, Yuanxing Chang, Weiwei Li, Ping Lu, Mengling Xia, Xianghua Zhang, and Yinsheng Xu
Tb-doped magneto-optical (MO) glass is widely used in fiber optics, optical isolators, and modulators. However, only the paramagnetic Tb3+ ions exhibit significant MO effects, whereas the diamagnetism Tb4+ ions suppress the MO effects. Therefore, the valence state control of Tb ions is very critical to optimize MO performance. Here, a reduction strategy was introduced to adjust the Tb valence in glass
-
Where is the orbital angular momentum in vortex superposition states? Opt. Express (IF 3.8) Pub Date : 2024-04-17 Huajie Hu, Hehe Li, Xueyun Qin, and Xinzhong Li
In this paper, we explore the distribution of the orbital angular momentum (OAM) in the coaxial vortex superposition states based on the independent propagation principle of light in this interference process. We find that in this case, some specific singular points exist in the spatial intensity distribution. The first type of singular point is located at the center point of the spatial intensity
-
Two-dimensional beam scanning by tunable photonic spin Hall effect Opt. Express (IF 3.8) Pub Date : 2024-04-18 Weichao Xie, Tingyu Lin, Huadan Zheng, Jianhui Yu, Yongchun Zhong, Zhe Chen, and Wenguo Zhu
To the best of our knowledge, a novel tunable photonic spin Hall effect is proposed based on a pair of liquid crystal Pancharatnam-Berry (PB) lenses. Owing to the spin-dependent geometric phases, a PB lens focus or defocus the incident light field according to its spin angular momentum. By cascading two PB lenses with a small gap, the focus and defocus effects can be suppressed, and the transmitted
-
Nonvolatile multilevel adjustable optical switch based on plasmonic slot waveguide and GST segmented structure Opt. Express (IF 3.8) Pub Date : 2024-04-19 Yiqun Zhang, Qiong Duan, Xu Yan, Qi Zhang, and Yegang Lu
Optical computing has gradually demonstrated its efficiency in handling increasingly complex computational demands, attracting widespread attention. Optical switches can effectively control and modulate optical signals, providing flexibility and efficiency for optical computing systems. However, traditional optical switches face performance issues such as power consumption, switching speed, and compactness
-
Dual-band and spectrally selective infrared absorbers based on hybrid gold-graphene metasurfaces Opt. Express (IF 3.8) Pub Date : 2024-04-19 Mahsa Alijabbari, Rouhollah Karimzadeh, Samaneh Pakniyat, and J. Sebastian Gomez-Diaz
In this paper, we propose a dual-band and spectrally selective infrared (IR) absorber based on a hybrid structure comprising a patterned graphene monolayer and cross-shaped gold resonators within a metasurface. Rooted in full-wave numerical simulations, our study shows that the fundamental absorption mode of the gold metasurface hybridizes with the graphene pattern, leading to a second absorptive mode
-
Development of a visible to 1600 nm hyperspectral imaging rigid-scope system using supercontinuum light and an acousto-optic tunable filter Opt. Express (IF 3.8) Pub Date : 2024-04-17 Toshihiro Takamatsu, Ryodai Fukushima, Kounosuke Sato, Masakazu Umezawa, Hideo Yokota, Kohei Soga, Abian Hernandez-Guedes, Gustavo M. Callico, and Hiroshi Takemura
In this study, we developed a rigid-scope system that can perform hyperspectral imaging (HSI) between visible and 1600 nm wavelengths using a supercontinuum light source and an acousto-optic tunable filter to emit specific wavelengths. The system optical performance was verified, and the classification ability was investigated. Consequently, it was demonstrated that HSI (490–1600 nm) could be performed
-
Nondestructive measurement of terahertz optical thin films by machine learning based on physical consistency Opt. Express (IF 3.8) Pub Date : 2024-04-18 Ziwei Ming, Defeng Liu, Long Xiao, Le Yang, Yuehuan Cheng, Haoming Yang, Jiahao Zhou, Hao Ding, Zhengang Yang, and Kejia Wang
Optical scattering measurement is one of the most commonly used methods for non-contact online measurement of film properties in industrial film manufacturing. Terahertz photons have low energy and are non-ionizing when measuring objects, so combining these two methods can enable online nondestructive testing of thin films. In the visible light band, some materials are transparent, and their thickness
-
Picosecond laser filament-guided electrical discharges in air at 1 kHz repetition rate Opt. Express (IF 3.8) Pub Date : 2024-04-18 K. Dehne, A. Higginson, Y. Wang, F. Tomasel, M. G. Capeluto, V. N. Shlyaptsev, and J. J. Rocca
Laser-induced filaments have been shown to reduce the voltage necessary to initiate electrical discharges in atmospheric air and guide their propagation over long distances. Here we demonstrate the stable generation of laser filament-guided electrical discharge columns in air initiated by high energy (up to 250 mJ) 1030 nm wavelength laser pulses of 7 ps duration at repetition rates up to 1 kHz and
-
Generation of attosecond electron bunches of tunable duration and density by relativistic vortex lasers in near-critical density plasma Opt. Express (IF 3.8) Pub Date : 2024-04-18 W. Y. Zhang, L. X. Hu, Y. Cao, F. Q. Shao, and T. P. Yu
Attosecond electron bunches have wide application prospects in free-electron laser injection, attosecond X/γ-ray generation, ultrafast physics, etc. Nowadays, there is one notable challenge in the generation of high-quality attosecond electron bunch, i.e., how to enhance the electron bunch density. Using theoretical analysis and three-dimensional particle-in-cell simulations, we discovered that a relativistic
-
Cluster sampling and scalable Bayesian optimization with constraints for negative tone development resist model calibration Opt. Express (IF 3.8) Pub Date : 2024-04-16 Le Ma, Xingyu Ma, Shaogang Hao, Lisong Dong, Yayi Wei, and Zhengguo Tian
As the semiconductor technology node continues to shrink, achieving smaller critical dimension in lithography becomes increasingly challenging. Negative tone development (NTD) process is widely employed in advanced node due to their large process window. However, the unique characteristics of NTD, such as shrinkage effect, make the NTD resist model calibration more complex. Gradient descent (GD) and
-
Removal of algorithmic stagnation by augmented iterative phase retrieval Opt. Express (IF 3.8) Pub Date : 2024-04-16 Areeba Fatima and Daniele Faccio
Retrieving the phase of an optical field using intensity measurements is one of the most widespread and studied inverse problems in classical optics. However, common iterative approaches such as the Gerchberg-Saxton algorithm and its derivatives suffer from the twin-image problem – the iterative minimisation stagnates and the recovered field contains features from both the target field and its point-reflection
-
High-precision measurements of terahertz polarization states with a fiber coupled time-domain THz spectrometer Opt. Express (IF 3.8) Pub Date : 2024-04-16 Zhenisbek Tagay, Ralph Romero, and N. P. Armitage
We present a new method for high precision measurements of polarization rotation in the frequency range from 0.2 to 2.2 THz using a fiber coupled time-domain THz spectrometer. A free standing wire-grid polarizer splits THz light into orthogonal components that are then measured by two separate detectors simultaneously. We theoretically model the uncertainties introduced by optical component non-idealities
-
Laboratory study of aberration calculation in underwater turbulence using Shack-Hartmann wavefront sensor and Zernike polynomials Opt. Express (IF 3.8) Pub Date : 2024-04-16 Amir Aghajani, Fatemeh Dabbagh Kashani, and Masoud Yousefi
This paper presents a laboratory study of the aberrations calculation in underwater turbulence using the Shack-Hartmann wavefront sensor. The wavefront decomposition method and Zernike polynomials determine the aberration parameters. In our experimental setup, the turbulent phase screen generator is located in two locations: near the transmitter and therefore far from the receiver, and near the receiver
-
Instantaneous frequency measurement system based on quantum dash mode-locked laser Opt. Express (IF 3.8) Pub Date : 2024-04-16 Yuxuan Xie, Mostafa Khalil, Jiaren Liu, Zhenguo Lu, Philip J. Poole, John Weber, Guocheng Liu, Mohamed Rahim, and Lawrence R. Chen
We present the theory and experimental results of a microwave photonic (MWP) filter based instantaneous frequency measurement system. A quantum dash mode-locked laser is used as an optical frequency comb source. With up to 41 flat comb lines and a real-time feedback loop for comb shaping, a set of MWP filters with linear frequency responses for either linear unit or dB unit are experimentally demonstrated
-
Hybrid integrated optical chaos circuits with optoelectronic feedback Opt. Express (IF 3.8) Pub Date : 2024-04-16 Yisi Wang, Zheng Wu, Boyu Li, Jisun Chen, Lijie Shen, Huihui Yang, Yuan Feng, XiangFei Chen, and Mi Li
A chip-scale chaotic laser system with optoelectronic delayed feedback is proposed and analyzed by numerical simulation. This chip eliminates the need for bulky delay components such as long optical fibers, free propagation and external cavities, relying solely on internal devices and waveguides to achieve feedback delay. This approach simplifies integration, maintaining a compact chip size. According
-
Ultrafast laser direct writing of material independent integrated nonlinear components based on NPE Opt. Express (IF 3.8) Pub Date : 2024-04-16 Longwang Xiu, Yu Wang, Xinyu Hu, and Xiangdong Cao
Material independent integrated nonlinear components (MIINC) based on nonlinear polarization evolution (NPE) play an important role in the emerging quantum computing, integrated photonics and ultrafast science. However, to our knowledge, no one has yet employed ultrafast laser direct writing for NPE-based MIINC. Here, for the first time, we finish the MIINC direct writing based on NPE using an ultrafast
-
Low phase noise cavity transmission self-injection locked diode laser system for atomic physics experiments Opt. Express (IF 3.8) Pub Date : 2024-04-16 L. Krinner, K. Dietze, L. Pelzer, N. Spethmann, and P. O. Schmidt
Lasers with high spectral purity are indispensable for optical clocks and for the coherent manipulation of atomic and molecular qubits in applications such as quantum computing and quantum simulation. While the stabilization of such lasers to a reference can provide a narrow linewidth, the widely used diode lasers exhibit fast phase noise that prevents high-fidelity qubit manipulation. In this paper
-
Spectroscopy and Kerr-lens mode-locked operation of Yb:GdScO3 crystal Opt. Express (IF 3.8) Pub Date : 2024-04-16 Longxin Liu, Siyuan Niu, Zhiyong Liang, Zhenxin Jiang, Qingsong Song, Zebin Wang, Peng Chen, Jian Liu, Wenlong Tian, Jie Ma, Xiaodong Xu, Kheirreddine Lebbou, and Jun Xu
A Kerr-lens mode-locked laser based on a Yb3+-doped disordered gadolinium scandate (Yb:GdScO3) crystal is reported for the first time, to the best of our knowledge. The crystal with the perovskite structure was grown using the Czochralski method, and its room temperature (RT) and low temperature (LT) spectra were also investigated. Due to the crystal's multisite structure (Gd3+/Sc3+ site), Yb:GdScO3
-
In-band pumped Kerr-lens mode-locked Tm,Ho-codoped calcium aluminate laser Opt. Express (IF 3.8) Pub Date : 2024-04-16 Huang-Jun Zeng, Wen-Ze Xue, Robert T. Murray, Chen Cui, Li Wang, Zhongben Pan, Pavel Loiko, Xavier Mateos, FeiFei Yuan, Ge Zhang, Uwe Griebner, Valentin Petrov, and Weidong Chen
We report on a Kerr-lens mode-locked Tm,Ho-codoped calcium aluminate laser with in-band pumping of the Tm ions by a spatially single-mode 1678 nm Raman fiber laser. The structurally disordered CaGdAlO4 host crystal is also codoped also with the passive Lu ion for additional inhomogeneous line broadening. The Tm,Ho,Lu:CaGdAlO4 laser generates soliton pulses as short as 79 fs at a central wavelength
-
Chiral plasmonic metasurface assembled by DNA origami Opt. Express (IF 3.8) Pub Date : 2024-04-16 Niels Gieseler, Svenja Moench, Dominik Beutel, Wolfgang G. Pfeifer, Carmen M. Domínguez, Christof M. Niemeyer, and Carsten Rockstuhl
Chiral materials are essential to perceive photonic devices that control the helicity of light. However, the chirality of natural materials is rather weak, and relatively thick films are needed for noticeable effects. To overcome this limitation, artificial photonic materials were suggested to affect the chiral response in a much more substantial manner. Ideally, a single layer of such a material,