2024

• Record 1 of
  
  Title:High-efficiency longwave 2085 nm laser output in low-loss Ho3+-doped fluorotellurite glass fiber by 1976 nm in-band pumping
  
  Author(s):Feng, Shaohua; Shen, Yewei; Zhu, Jun; Liu, Chengzhen; Xu, Yantao; Xiao, Xusheng; Guo, Haitao
  Source: OPTICS AND LASER TECHNOLOGY  Volume: 177  Issue:   DOI: 10.1016/j.optlastec.2024.111179  Published: 2024  
  Abstract:High-gain Ho3+-doped optical fibers are imperative exigency for > 2 mu m single-mode fiber lasers. Here, we have successfully developed and fabricated a low-loss Ho3+-doped fluorotellurite glass fiber. The high-power laser irradiation tolerance of the fiber was verified, and the end face of Ho3+-doped fluorotellurite glass fiber remained undamaged under a similar to 70 W of 981 nm CW laser irradiation. An unsaturated maximum 6.35 W@2085 nm single-mode laser output with a slope efficiency of 90.4 % was achieved in a 25 cm short fiber by homemade 1976 nm laser in-band pumping. To the best of our knowledge, this is currently the highest slope efficiency reported for Ho3+ doped fluorotellurite fiber lasers to date in a space laser cavity. The effects of the fiber length on the laser threshold, slope efficiency, and output wavelength are further discussed. This work offers valuable insights into prospective candidate materials and scheme designs for the future development of high-efficiency, long-wavelength mid-infrared similar to 2.1 mu m fiber lasers.
  Accession Number: 111179
  ISSN: 0030-3992
  eISSN: 1879-2545
• Record 2 of
  
  Title:Low self-starting threshold polarization-maintaining Er-doped fiber optical frequency comb
  
  Author(s):Gao, Yanwei; Cheng, Haihao; Hu, Xiaohong; Li, Yongqi; Liu, Hao; Yang, Yanzhao; Pan, Ran; Wang, Yishan; Wu, Shun
  Source: OPTICS AND LASER TECHNOLOGY  Volume: 177  Issue:   DOI: 10.1016/j.optlastec.2024.111092  Published: 2024  
  Abstract:We report the development of an all-fiber polarization maintaining (PM) optical frequency comb using a modelocked figure -9 laser with a low self-starting pump threshold. We have achieved self-starting mode -lock for repetition rates ( f r ) from 70 MHz to 109 MHz. At a repetition rate of 109 MHz, mode-locking can be achieved for a pump power ranging from 187 mW to 880 mW. To the best of our knowledge, this is the lowest pump power reported for PM figure -9 erbium fiber lasers with repetition rate over 100 MHz. By optimizing the pump power to 238 mW, we have achieved an output power of 5 mW, center wavelength of 1566.2 nm, and 3 -dB spectral bandwidth of 20.5 nm. The repetition rate has a high signal -to -noise ratio of 95 dB at a resolution bandwidth of 300 Hz. We have studied the spectral characteristics of the laser under different cavity lengths and pump powers. Additionally, we have stabilized the repetition rate using a GPS-Rb disciplined RF reference. The fractional instability of the repetition rate is measured to be 4 .67 x 10 - 12 at 1 s and 9 .22 x 10 - 13 at 10 s over a measurement of 11 h. Our findings demonstrate that the developed figure -9 comb is robust, compact and has the advantage of high stability and low power consumption. It offers a cost effective solution for future outdoor comb applications.
  Accession Number: 111092
  ISSN: 0030-3992
  eISSN: 1879-2545
• Record 3 of
  
  Title:Rotating dual-retarders to correct polarization measurement error for division-of-amplitude polarimeter in full field of view
  
  Author(s):Jia, Wentao; Liu, Kai; Jiang, Kai; Shan, Qiusha; Duan, Jing; Wu, Linghao; Zhou, Liang
  Source: OPTICS AND LASERS IN ENGINEERING  Volume: 181  Issue:   DOI: 10.1016/j.optlaseng.2024.108360  Published: 2024  
  Abstract:The division -of -amplitude polarimeter (DoAP) can measure the four Stokes parameters simultaneously, and has the advantages of snapshot and high spatial resolution. However, the residual polarization aberration (PA) of DoPA system can lead to the polarization measurement error, which is influenced by the field of view. In this paper, the relationship between the measurement errors of Stokes parameters and the Mueller pupil is derived, and the Mueller pupil of DoPA system is obtained by 3D polarization ray -tracing matrix. Then, a method of dualretarders rotation is proposed to correct the Mueller pupil in full field of view. The simulation demonstrates the PA correction can improve the measurement accuracy of DoPA system, and the measurement error of degree of linear polarization is reduced by 11.5 %, 38.2 % and 11.8 % at 0 degrees , 10 degrees and 15 degrees field of view, respectively. This research facilitates the precise measurement of polarization signals for polarimeters.
  Accession Number: 108360
  ISSN: 0143-8166
  eISSN: 1873-0302
• Record 4 of
  
  Title:Optical diffraction tomography based on quadriwave lateral shearing interferometry
  
  Author(s):Yuan, Xun; Min, Junwei; Zhou, Yuan; Xue, Yuge; Bai, Chen; Li, Manman; Xu, Xiaohao; Yao, Baoli
  Source: OPTICS AND LASER TECHNOLOGY  Volume: 177  Issue:   DOI: 10.1016/j.optlastec.2024.111124  Published: 2024  
  Abstract:Optical diffraction tomography (ODT) is an emerging microscopy that enables quantitatively three-dimensional (3D) refractive index (RI) mapping of subcellular structure inside biological cells without staining. Due to the noninvasive, label -free, and quantitative imaging capability, ODT has become an important technique in the fields of cell biology, biophysics, hematology, and so on. It is customary to acquire a set of two-dimensional (2D) phase images of a transparent sample from different illumination angles by using the classical Mach-Zehnder interferometry (MZI), and then numerically reconstruct the 3D RI distribution of the sample via appropriate tomographic algorithms. However, due to the limited stability of MZI, the cumulative measured phase errors reduce the accuracy of the reconstructed RI. Here, we propose a common -path ODT based on quadriwave lateral shearing interferometry (QLSI), referred as Q-ODT. In QLSI, the object beam carrying the phase information of sample is divided into four copies by a specially designed 2D diffraction optical element, then the diffracted waves interfere with each other to form the interferogram at the image plane. The complex amplitude map of the object is quantitatively retrieved from the single -shot interferogram by using a Fourier analysis algorithm and a 2D phase gradient integration. A spatial light modulator is employed to ensure high -precision illumination angle scanning without mechanical motion by addressing a series of different periods and orientations blazed gratings. The average fluctuation of the measured phases of a test polystyrene bead by acquiring 300 interferograms in 12 s presents 7.6 mrad, surpassing the conventional MZI-based ODT. The 3D RI distribution of the bead reconstructed from 145 complex amplitude maps via multi -illumination angles with a maximum angle of 70 degrees matches the manufacturer ' s specification well, demonstrating the high accuracy of the 3D RI imaging capability of the QODT. The lateral and axial resolutions of the 3D RI reconstruction were measured to be 306 +/- 21 nm and 825 +/- 34 nm, respectively. The proposed Q-ODT method successfully reconstructed the intracellular structure of the biological specimens of Eudorina elegans and mouse bone mesenchymal stem cells (BMSC). The Q-ODT offers a new route towards 3D RI imaging for label -free transparent samples in biomedical research.
  Accession Number: 111124
  ISSN: 0030-3992
  eISSN: 1879-2545
• Record 5 of
  
  Title:Power-Guided Asymmetrical Vector Dissipative Soliton Molecules in a Compact Fiber Resonator
  
  Author(s):Huang, Xiangzhen; Li, Xiaohui; Chen, Enci; Pan, Zhiwen; Guo, Penglai; Sun, Liaoxin; Wang, Yishan; Zhao, Wei
  Source: IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS  Volume: 30  Issue: 5  DOI: 10.1109/JSTQE.2023.3319342  Published: 2024  
  Abstract:Vector dissipative soliton molecules (VDSMs) can be promising for polarization multiplexing transmission applications. We report a nonlinear polarization rotation (NPR) vector dissipative soliton molecule laser. The laser realizes three-type vector dissipative soliton molecules of directly generated 1+2 type, 2+2 type, and outer-cavity projected super-position 2+'2+2' type just by changing the pump power. It's proved that the different generated methods of vector soliton molecules in Hamiltonian systems can also be realized in dissipative systems. This is also the first time that multiple different generated methods of vector dissipative soliton molecules are realized in a fiber resonator based on NPR. The results proved the VDSMs' structures can be controlled, which can be potentially applied in optical frequency comb, optical communication systems, optical logic processing, optical detection, etc.
  Accession Number: 2100106
  ISSN: 1077-260X
  eISSN: 1558-4542
• Record 6 of
  
  Title:Underwater image enhancement via color correction and multi-feature image fusion
  
  Author(s):Ke, Ke; Zhang, Biyun; Zhang, Chunmin; Yao, Baoli; Guo, Shiping; Tang, Feng
  Source: MEASUREMENT SCIENCE AND TECHNOLOGY  Volume: 35  Issue: 9  DOI: 10.1088/1361-6501/ad4dca  Published: 2024  
  Abstract:The light attenuation underwater causes the actual underwater images to suffer from color cast, low contrast, and weak illumination. To address these issues, an effective fusion-based method is proposed, which realizes color correction (CC), brightness adjustment, contrast, and detail enhancement of underwater images. Concretely, we first design an adaptive CC method via dominant color channel judgment and lower color channel compensation. Then, we detect the brightness of each input image and propose a gamma correction function based on the gradient of the cumulative histogram to adjust the brightness of the low-light images. Subsequently, global histogram stretching and adaptive fractional differentiation techniques are employed to process the brightness-adjusted image, and then the global contrast-enhanced version and detail-enhanced version are generated respectively. To integrate the advantages of both versions, a channel fusion method based on the Lab color space is used to fuse the luminance and color of the two versions separately. The experimental results demonstrate the effectiveness of the proposed method in improving the color and illumination of underwater images, as well as enhancing the clarity of images. Moreover, the testing results on multiple datasets validate the excellent stability of this method.
  Accession Number: 96123
  ISSN: 0957-0233
  eISSN: 1361-6501
• Record 7 of
  
  Title:Fundamental and dipole gap solitons and their dynamics in the cubic-quintic fractional nonlinear Schrödinger model with a PT-symmetric lattice
  
  Author(s):Wang, Li; Zeng, Jianhua; Zhu, Yi
  Source: PHYSICA D-NONLINEAR PHENOMENA  Volume: 465  Issue:   DOI: 10.1016/j.physd.2024.134144  Published: 2024  
  Abstract:The interplay of two linear controlled terms - fractional diffraction and parity-time (PT ) symmetric lattice - gives rise to unique and interesting linear Bloch gap structures within where the nonlinear localized gap modes may exist. In this study, we explore the formation and dynamics of one-dimensional gap solitons in the cubic-quintic physical model combining the fractional diffraction and PT symmetric lattice. Two classes of gap solitons, which we name the fundamental gap solitons and dipole ones, are constructed and their stability regions within the first finite gap of the associated linear Bloch spectrum are identified by means of linear-stability analysis and direct perturbed numerical simulations. We stress that the gap solitons are always unstable under the condition of PT symmetry breaking (the imaginary part of which is above 0.5). The excitations of the stable two classes of gap solitons are also investigated by using the adiabatic variation of the system's parameters. The results predicted here shed some light on soliton physics in physical systems with combined fractional diffraction and PT symmetric lattice and the competing nonlinearities.
  Accession Number: 134144
  ISSN: 0167-2789
  eISSN: 1872-8022
• Record 8 of
  
  Title:Fourier ptychographic reconstruction with denoising diffusion probabilistic models
  
  Author(s):Wu, Kai; Pan, An; Gao, Wei
  Source: OPTICS AND LASER TECHNOLOGY  Volume: 176  Issue:   DOI: 10.1016/j.optlastec.2024.111016  Published: 2024  
  Abstract:Fourier ptychographic microscopy (FPM) is a promising computational imaging technique that can bypass the diffraction limit of the objective lens and achieve high-resolution, wide field-of-view imaging. The FPM setups firstly capture a series of low-resolution (LR) intensity images by angle-varied illumination and then reconstruction algorithms recover the high-resolution (HR) complex-valued object from the LR measurements. The image acquisition process commonly introduces noise, ultimately leading to degradation in the quality of the reconstruction results. In this paper, we report a noise-robust Fourier ptychographic reconstruction method that generates the HR complex-valued object estimation using the image priors specified by denoising diffusion probabilistic models (DDPM). First, the initial estimation of the HR complex-valued object is matched with an intermediate state in the Markov chain defined by DDPM. Then, the noisy initial solution is iteratively updated to a high-quality reconstruction result in the reverse process of DDPM and gradient descent correction is incorporated to enforce data consistency with the LR measurements. The proposed method integrates DDPM specified image priors and gradient descent correction, achieving solutions with less noise-related artifacts and high fidelity for HR complex-valued object estimation in Fourier ptychographic reconstruction. We apply the proposed method on both synthetic and real captured data. The experimental results show that our method can efficiently suppress the impact of noise and improve reconstruction results quality.
  Accession Number: 111016
  ISSN: 0030-3992
  eISSN: 1879-2545
• Record 9 of
  
  Title:Dynamic multi-focus laser sculpting of freeform 3D glass microstructures
  
  Author(s):Yao, Li; Xu, Kang; Huang, Lingyu; Huang, Peilin; Li, Zongyao; Wang, Pu; Xu, Shaolin
  Source: OPTICS AND LASERS IN ENGINEERING  Volume: 180  Issue:   DOI: 10.1016/j.optlaseng.2024.108278  Published: 2024  
  Abstract:The three-dimensional (3D) sculpturing of glass remains a significant challenge owing to its inherent hard and brittle nature. We develop a novel dynamic multi-focus laser sculpting (DMLS) method tailored for 3D glass fabrication. This method employs two-dimensional (2D) spatial multi-focus beams to form sectional profiles of 3D structures, which are modulated by superimposing the phase of Fresnel lenses and blazed gratings. With dynamic switching of phase diagrams on a spatial light modulator, the multi-focus beam rotates and creates a customized 3D laser-modified region inside the bulk glass. Following chemical etching helps remove the modified zones, forming ultimate 3D morphology on glass surface. The feasibility of this method hinges upon achieving uniform foci energy and narrow spatial foci intervals, essential for the precise removal of modified regions through connected crack channels during etching. We propose an extracting strategy to separate foci with random sequences into several groups to disrupt the periodicity of foci, thereby effectively weakening the unexpected Moire fringes on the phase diagrams. This strategy enables the forming of dense foci by a single diagram with high uniformity, shortening the interval between foci. Further, for the lower surface roughness and higher precision of 3D structures, optimization of fabrication parameters is applied by experimental and numerical analysis. With the above optimization, the DMLS method is capable of carving diversified 3D glass structures, including hemispheres, cones, pyramids, semi-ellipsoids, and petal-like structures. Our method exhibits considerable versatility in processible structures with shape deviation lower than 1.9 mu m, showing substantial potential in glass processing.
  Accession Number: 108278
  ISSN: 0143-8166
  eISSN: 1873-0302
• Record 10 of
  
  Title:A 90Sr/90Y-radioisotope battery based on betavoltaic and beta-photovoltaic dual effects
  
  Author(s):Cui, Qiming; Lu, Jingbin; Li, Xiaoyi; Yuan, Xinxu; Zhao, Yang; Zheng, Renzhou; Li, Qingyang; Wei, Jie; Luo, Baifeng; Lin, Li
  Source: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING  Volume: 179  Issue:   DOI: 10.1016/j.mssp.2024.108493  Published: 2024  
  Abstract:Betavoltaic batteries with strontium sources are expected to achieve higher output power because of their high energy density and low self-absorption rate with the development of MEMS. However, the high energy of beta particles emitted from Sr-90/Y-90 can prone to radiation damage of the semiconductor. In order to exploit the high energy of beta particles emitted from Sr-90/Y-90 and to avoid radiation damage to the semiconductor, this paper presents a Sr-90/Y-90- radioisotope battery based on betavoltaic (BV) and beta -photovoltaic (BPV) dual effects. In the work, the energy deposition of beta particles in LYSO:Ce and GaAs was simulated by Monte Carlo code, and thickness of the scintillator was determined. And the doping concentrations and junction depth of semiconductor were optimized based on the theoretical calculations to obtain the best output performance of device. When the thickness of LYSO:Ce is 0.158 cm, the output power density P-m of the optimized dualeffect battery is 0.61 mu W/cm(2) . And the conversion efficiency of the device is 0.92%. At this time, the doping concentrations are N-a = 1 . 58 x 10(17) cm(-3) and N-d = 3 . 16 x 10(18) cm(-3) , and the junction depth x(j )= 0 . 05 mu m. All calculated parameter values are considered as theoretical limit values. In addition, the contribution of BV effect and BPV effect to the output performance of the dual -effect radioisotope battery was investigated. Different scintillator thicknesses lead to different percentages of the two mechanics. In addition, the BV effect and BPV effect output proportion is also affected by the average energy of the radiation source. In the case that the average electron energy on the semiconductor surface is 0.27 MeV, the higher the radioactive source energy, the thicker the scintillator is required, resulting in more BPV effect and less BV effect.
  Accession Number: 108493
  ISSN: 1369-8001
  eISSN: 1873-4081
• Record 11 of
  
  Title:Structural insight of fluorophosphate glasses through F/O ratio: Case study of Raman and NMR spectra
  
  Author(s):Cao, Xin; Wang, Pengfei; Wan, Rui; Guo, Chen; Tian, Shuai
  Source: JOURNAL OF NON-CRYSTALLINE SOLIDS  Volume: 637  Issue:   DOI: 10.1016/j.jnoncrysol.2024.123065  Published: 2024  
  Abstract:Fluorophosphate glass has excellent characteristics such as low nonlinear refractive index, anomalous partial dispersion, low phonon energy, high UV transparency and high rare earth doping concentration, etc. The two anion ions of fluorine (F) and oxygen (O) and their F/O ratio in fluorophosphate glasses provide important structural characteristics of the specific glass. To explore this, a series of fluorophosphate glass samples with theoretical F/O ratios ranging from 1 to 7 were prepared, Raman spectroscopy and 31P nuclear magnetic resonance (NMR) spectroscopy were mainly employed to elucidate the structural polyhedrons made of the network chain. The underlying correlation between the Qn units and F/O ratio was explored, i.e., the Q2 unit dominate when the F/O ratio is less than 0.3, and predominantly Q2 or Q1 unit is predominant as F/O ratio ranges from 0.3 to 1, it comes to be Q1 or Q0 unit as F/O ratio further increase to 4, while it becomes Q0 when the F/O ratio is greater than 4. The applicability of this interval estimation was verified by comprehensive analyzing a variety of structural results of fluorophosphate glasses with various glass compositions. The explored interrelation between the F/O ratio and structural property is of great significance for developing low nonlinear and UV transparent fluorophosphate glasses.
  Accession Number: 123065
  ISSN: 0022-3093
  eISSN: 1873-4812
• Record 12 of
  
  Title:Tailoring the visible light band of Watt-level SCs pumped via picosecond pulse with different Raman extent
  
  Author(s):Guo, Yashuai; Wang, Zhenguang; Hu, Xiaohong; Zhang, Ting; Zhang, Zhao; Zhang, Wei; Wang, Yishan
  Source: LASER PHYSICS  Volume: 34  Issue: 8  DOI: 10.1088/1555-6611/ad552f  Published: 2024  
  Abstract:We investigate the supercontinuum (SC) tailoring property by varying the transmission fiber length after the master oscillator power amplifier system. The conversion efficiency of the visible light band is effectively enhanced via tailoring the Raman extent of the injected 30 ps pulse into the nonlinear photonic crystal fiber (PCF). Experimentally, a 3.6 W all-fiber SC spanning from 414 nm to over 1750 nm (@20 dB) is accomplished by using a high duty cycle domestic PCF through precisely controlling the extent of Raman effect. The proposed method is instructive for the further realization of high power SC with an enhanced spectral intensity in the visible light band.
  Accession Number: 85102
  ISSN: 1054-660X
  eISSN: 1555-6611