2022

• Record 337 of
  
  Title:Research and Development of Key Technologies and Equipment for Multiaxis CNC Laser Engraving
  
  Author(s):Liu, Qiang(1,4); Wang, Jian(1,5); Sun, Pengpeng(1,6); Li, Ming(2); Wang, Hui(3); Yin, Zhenshuo(1,4); Wang, Liuquan(1,5); Li, Kunhang(3)
  Source: Zhongguo Jiguang/Chinese Journal of Lasers  Volume: 49  Issue: 10  DOI: 10.3788/CJL202249.1002401  Published: May 25, 2022  
  Abstract:Objective As a new pattern engraving method of chemical milling parts, laser engraving is one of the important processes in chemical milling for aeroengine casing. This technique can effectively improve the precision and the efficiency of chemical milling. Moreover, it is greatly significant in improving the thrust-weight ratio and the manufacturing efficiency of the aeroengine. In the laser engraving process, according to the numerical control (NC) machining program based on the geometric pattern information and the process parameters of chemical milling, the geometric pattern is engraved on the protective adhesive layer by laser ablation under the control of the optical electromechanical cooperative control system. Laser engraving combines laser processing with the NC technology and a digital manufacturing process that has high precision and efficiency, digitization, and flexibility. The method can also be used for primary/secondary engraving on complex surfaces to solve the engraving bottleneck problem of aerospace complex thin-walled structures. The laser engraving research in China is still in its initial stage and mainly focuses on investigating the primary laser engraving process parameters and the engineering application of foreign laser engraving machines. Less research has been conducted on the key technologies and equipment used for the laser engraving of three-dimensional (3D) complex structure parts, and many technical difficulties have not yet been overcome. This work investigates the key technologies of the engraving process parameters, including laser engraving trajectory planning, optical electromechanical collaborative optimization model, and adaptive matching mechanism. The six-axis, five-linkage NC laser engraving machine tool is developed to provide a new solution to the bottleneck problem of engraving in the chemical milling of the complex thin-walled structures of the aerospace. Methods First, based on the laser multiple engraving process, a laser engraving trajectory planning algorithm considering the chemical milling evolution is proposed herein to solve the laser engraving problem of the complex surface on aeroengine casing. The basic processes of trajectory planning and automatic programming of the pattern features for multiple laser engraving are given. The multi-axis motion trajectory of the laser engraving position and direction is fitted by a complete B-spline curve and a segmented double B-spline curve. The number of control points and the fitting error of the curve are then analyzed. Second, an opto-mechatronics collaborative optimization model is established aiming at the minimum processing time and the minimum width of the heat-affected zone while the adhesive layer is etched through. In this model, the bow height error of the trajectory curve, speed, acceleration, and jerk of the feed axis are considered. Furthermore, the minimum processing time is equivalent to the maximum feed speed. Third, an adaptive matching optimization algorithm for the engraving process parameters is established to solve the optimization problem of the motion and laser process parameters. The laser process parameters that satisfy the constraints under different speed conditions are simulated and calculated, providing theoretical parameters for the optical electromechanical cooperative control of laser engraving. Finally, the structure of the six-axis, five-linkage NC laser engraving machine tool, the high-precision optical path flexible transmission and positioning, and the optical electromechanical cooperative control system are implemented. The six-axis, five-linkage NC laser engraving machine tool is developed to realize the application of primary/secondary laser engraving. Results and Discussions First, for the trajectory planning of the laser engraving position points, a complete B-spline curve and a segmented B-spline curve are used to generate the trajectory that meets the accuracy requirements. The fitting accuracy of each curve is less than 0.008 mm (Fig. 5). To ensure the fitting accuracy, the complete B-spline curve needs more control points, while the segmented B-spline curve needs less control points (Table 1). The segmented double B-spline curve is used to generate the trajectory for the engraving position and direction. The fitting accuracy of the segmented double B-spline curve of the laser engraving position and direction can reach 0.005 mm (Fig. 5). The maximum error of the direction vector angle by the segmented double B-spline curve is 0.0061 rad, which effectively meets the laser engraving process requirements. Second, the simulation results of the opto-mechatronics collaborative optimization model illustrate that the energy in the heat-affected zone exceeding the threshold is mainly considered in the low-speed movement section. In addition, the engraving speed is increased to ensure the engraving quality (Fig. 8). The kinematic constraints of the equipment are mainly considered to complete the engraving processing with the highest efficiency in the high-speed movement section. The comprehensive balance between the engraving quality and efficiency is realized in this model. Third, to optimize the motion and process parameters in the engraving process, the comprehensive optimization results under different weight conditions are given, and the corresponding process parameters of the laser energy density and the duty ratio under different speeds are calculated (Fig. 9). Different laser motion and laser parameters can be quickly selected through different weight settings. Fourth, the primary engraving/secondary engraving of the annular thin-walled milling cylinder parts of an aeroengine casing is realized. The accuracy error of the secondary laser engraving can reach 0.034 mm, meeting the process requirements of the secondary laser engraving accuracy that should be less than 0. 05 mm. Conclusions This study investigates the key technologies of the laser engraving process, including laser engraving feature trajectory planning and automatic programming, collaborative optimization control of the laser engraving process, high-precision optical path flexible transmission and positioning, and optical electromechanical collaborative control system. The principle and engineering prototypes of the six-axis, five-linkage NC laser engraving machine tool are successfully developed, consequently providing the key technologies and the equipment support for solving the laser engraving problem of aerospace chemical milling structural parts. The key technologies of the laser engraving process and the six-axis, five-linkage NC laser engraving machine tool will not only solve the manufacturing problem of aerospace chemical milling parts, they can also be widely used in the fine manufacturing of 3D complex surfaces, which will effectively improve the performance and the manufacturing efficiency of major instruments and equipment. © 2022 Science Press. All rights reserved.
  Accession Number: 20224513069722
• Record 338 of
  
  Title:High parametric efficiency in laser cavity-soliton microcombs
  
  Author(s):Cutrona, Antonio(1,2); Rowley, Maxwell(2); Das, Debayan(1,2); Olivieri, Luana(1,2); Peters, Luke(1,2); Chu, Sai T.(3); Little, Brent E.(4); Morandotti, Roberto(5); Moss, David J.(6); Totero Gongora, Juan Sebastian(1,2); Peccianti, Marco(1,2); Pasquazi, Alessia(1,2)
  Source: Optics Express  Volume: 30  Issue: 22  DOI: 10.1364/OE.470376  Published: October 24, 2022  
  Abstract:Laser cavity-soliton microcombs are robust optical pulsed sources, usually implemented with a microresonator-filtered fibre laser. In such a configuration, a nonlinear microcavity converts the narrowband pulse resulting from bandwidth-limited amplification to a background-free broadband microcomb. Here, we theoretically and experimentally study the soliton conversion efficiency between the narrowband input pulse and the two outputs of a four-port integrated microcavity, namely the 'Drop' and 'Through' ports. We simultaneously measure on-chip, single-soliton conversion efficiencies of 45% and 25% for the two broadband comb outputs at the 'Drop' and 'Through' ports of a 48.9 GHz free-spectral range micro-ring resonator, obtaining a total conversion efficiency of 72%. Journal © 2022.
  Accession Number: 20224313005172
• Record 339 of
  
  Title:Signal recovery of a Fabry-Pérot interferometric x-ray pulse detector based on the RadOptic effect
  
  Author(s):Wang, Gang(1,2); He, Kai(1); Liu, Yiheng(1,2); Yan, Xin(1); Gao, Guilong(1); Wang, Tao(1); Yuan, Xiaohui(3); Zhao, Xu(3); Dong, Yufeng(4); Tian, Jinshou(1,5)
  Source: Journal of Applied Physics  Volume: 131  Issue: 6  DOI: 10.1063/5.0073295  Published: February 14, 2022  
  Abstract:The signal recovery of a Fabry-Pérot interferometric x-ray pulse detector based on the RadOptic effect in the non-limiting case was investigated in this research. A Fe-doped InP with an invariant excess carrier recombination mechanism was used as the interference cavity material to achieve a constant temporal instrumental response function (tIRF). A linear and time-invariant detection system described by the convolution of the time-varying x-ray pulse and the constant tIRF was established based on the transient refractive index variation model determined by the three effects of band filling, band shrinkage, and free-carrier absorption. For the non-limiting case, the accumulation of excess carriers enhanced the sensitivity but altered the fluctuations of the real x-ray pulse. To realistically reconstruct the x-ray pulse, two-photon absorption of the infrared ultrashort pulse was used to simulate the ultrashort x-ray excitation to obtain the tIRF. Finally, using the conjugate gradient method, the original signal recorded by the detection system was deconvoluted to recover the signal. The success of signal recovery in the non-limiting case provided the basis for the development of detectors with adjustable sensitivity controlled by carrier lifetime. © 2022 Author(s).
  Accession Number: 20220911705236
• Record 340 of
  
  Title:Zoom optical system design for an acousto-optic tunable filter camera assisted by programming multidimensional analysis
  
  Author(s):Gao, Duorui(1,2); Li, Tianlun(3)
  Source: Applied Optics  Volume: 61  Issue: 19  DOI: 10.1364/AO.461525  Published: July 1, 2022  
  Abstract:A medium infrared 12× continuous zoom optical system serving for an acousto-optic tunable filter spectral camera has been designed covering a 25–300 mm zooming range. Instead of relying on past experience for roughly determining the initial optical structure, a simulation programming based on Gaussian principle has been composed via MATLAB to accurately calculate the initial designing parameters, which is confirmed to be extremely close to the optimized results using Zemax. The relative design results have been multidimensionally analyzed in detail, which offers fresh thinking for future zoom optical design covering broadband operation wave band. © 2022 Optica Publishing Group
  Accession Number: 20222612275425
• Record 341 of
  
  Title:QPSK to BPSK modulation format conversion by phase-sensitive parametric amplification in multi-slot waveguides
  
  Author(s):Wu, Xiao(1); Li, Xuefeng(2); Ren, Li(1); Liu, Hongjun(3,4)
  Source: Applied Optics  Volume: 61  Issue: 32  DOI: 10.1364/AO.472444  Published: November 10, 2022  
  Abstract:The optical modulation conversion of a quadrature phase-shift keying (QPSK) signal to two binary phase-shift keying (BPSK) signals is theoretically realized in a phase-sensitive amplification (PSA) conversion system. We propose a multi-slot silicon-carbon nanotube/polydimethylsiloxane hybrid waveguide to achieve high nonlinearity of 108 W−1 m−1 for improving PSA performance. Constellation diagrams, error vector magnitude, and bit error rate (BER) are used to investigate and measure the performance of the output. The results show that the converted BPSK signal has more than a 10 dB higher signal-to-noise ratio than the QPSK signal with a BER threshold of 10−3. Furthermore, the system has great potential for hierarchical modulation of advanced format signals and long-distance transmission. © 2022 Optica Publishing Group.
  Accession Number: 20224713157120
• Record 342 of
  
  Title:Second-harmonic generation in a high-index doped silica micro-ring resonator
  
  Author(s):Li, Yuhua(1,2); Wang, Shao Hao(3); Ho, Wai Lok(2); Zhu, Xiaotian(2); Wang, Xiang(4); Davidson, Roy R.(4); Little, Brent E.(5); Chen, Rui-Pin(1); Chu, Sai Tak(2)
  Source: Optics Letters  Volume: 47  Issue: 15  DOI: 10.1364/OL.463317  Published: August 1, 2022  
  Abstract:We report the first, to the best of our knowledge, observation of second-harmonic generation (SHG) in a high-index doped silica micro-ring resonator, due to the symmetry-breakinginduced χ(2) at the core and cladding interface of the waveguide. The generated SH power is shown to have quadratic dependence on the in-cavity power of the fundamental pump at around 1550 nm. The pumping wavelength sweep method is adopted to fulfill the phase-matching condition for maximum conversion efficiency of SHG. This work offers a new approach to generate a visible source for the visible-light integrated optical platform from infrared-visible light conversion. © 2022 Optica Publishing Group.
  Accession Number: 20223212542425
• Record 343 of
  
  Title:Design of Real-time Target Detection System in CCD Vertical Target Coordinate Measurement
  
  Author(s):Zhang, Xin(1); Ding, Lu(1); Xu, Zhaohui(1); Liu, Hui(1)
  Source: 2022 3rd International Conference on Information Science, Parallel and Distributed Systems, ISPDS 2022  Volume:   Issue:   DOI: 10.1109/ISPDS56360.2022.9874125  Published: 2022  
  Abstract:High speed dim and small target detection is an important technology in CCD vertical target coordinate measurement. Its difficulty lies in the high frame rate real-time image processing speed requirements, weak and small target capture rate and extraction accuracy is not high [1]. In order to solve these problems, FPGA is designed and applied as the core of embedded hardware platform, and high-efficiency parallel operation, background iteration and false target detection algorithm are used to realize the real-time detection of high-speed weak and small targets in CDD images with a frame rate of 4096 lines up to 50KHz. The time delay of target acquisition and output measurement results is less than 10 ms, and the real-time performance is very good. In a certain application, under the background illumination of sky, the capture rate of dim high-speed projectile (5.8 mm projectile) can reach 100%, and the measurement accuracy σ is less than 13 mm, and the acquisition rate test of targets larger than 5.8 mm reaches a higher standard. © 2022 IEEE.
  Accession Number: 20224012819015
• Record 344 of
  
  Title:Weak Incoherent Optical Signal Amplification Based on Modulation Instability for Imaging Through Fog
  
  Author(s):Wang, Zhaolu(1); Zhang, Yongbin(1,3); Huang, Nan(1); Liao, Yuan(1); Zhang, Changchang(1); Gao, Xiaohui(2); Liu, Hongjun(1,4)
  Source: IEEE Photonics Journal  Volume: 14  Issue: 2  DOI: 10.1109/JPHOT.2022.3158653  Published: April 1, 2022  
  Abstract:Weak optical signal processing based on nonlinear effects offers new approaches for imaging through scattering media. A novel incoherent optical signal amplification method based on spatial modulation instability is proposed for imaging through fog. We experimentally demonstrated the amplification and recovery of degraded weak incoherent optical image signals after passing through dense fog in a photorefractive crystal. Our experimental results indicate that the intensity profiles of the output images can be redistributed from disordered to ordered when the nonlinear strength exceeds the threshold of incoherent modulation instability, which shows that the partially disordered incoherent probe light intensities are orderly transferred to enhance the signal intensity profiles and the residuals become a uniform background. The restored nonlinear output images with high visibility were observed for a proper optical thickness of fog, and weak optical imaging from undetectable to detectable with relatively poor visibility for a larger optical thickness was also realized in the experiment. This incoherent optical signal amplification method based on modulation instability has a potential application for image recovery in atmospheric scattering imagings. © 2009-2012 IEEE.
  Accession Number: 20221211817928
• Record 345 of
  
  Title:Phase regeneration of 8PSK signal using phase-sensitive amplification based on an organic-Ge hybrid waveguide
  
  Author(s):Ren, Li(1); Li, Xuefeng(2); Wu, Xiao(1); Liu, Hongjun(3)
  Source: Applied Optics  Volume: 61  Issue: 24  DOI: 10.1364/AO.463018  Published: August 20, 2022  
  Abstract:We numerically demonstrate the phase regeneration of eight-phase-shift keying (8PSK) in an organic-Ge hybrid waveguide with 10 μm length. Through filling graphene oxide with a high Kerr coefficient and engineering of waveguide dimensions, an ultrahigh nonlinear coefficient with 5.86x106 W-1 m-1 is attained at 1550 nm. The phase regeneration of 8PSK signal is achieved by using phase-sensitive amplification of the dual-conjugated-pump degenerate four-wave mixing scheme. The error-vector magnitude (EVM), optical signal-to-noise ratio, as well as constellation diagrams of 8PSK signal are also used to evaluate the phase regeneration capacity quantitatively. A reduction of EVM from 39.25% to 1.34% for 8PSK signal is found. The results show great phase regeneration and noise-squeezing ability, which indicate that such a phase-sensitive amplifier of a waveguide can find critical promising applications in all-optical signal processing. ©2022 Optica Publishing Group.
  Accession Number: 20223312573915
• Record 346 of
  
  Title:Tolerance enhancement of inefficient detection and frequency detuning by non-perfect phase-sensitive amplification in broadband squeezing-based precision measurement
  
  Author(s):Zhang, Changchang(1,2); Wang, Zhaolu(1); Liu, Hongjun(1,3); Huang, Nan(1)
  Source: Journal of the Optical Society of America B: Optical Physics  Volume: 39  Issue: 10  DOI: 10.1364/JOSAB.469228  Published: October 1, 2022  
  Abstract:Phase-sensitive amplification (PSA) can significantly improve the degradation caused by inefficient detectors in squeezing-based precision measurements. However, broadband incident light will lead to non-perfect PSA. The present work focused on the enhancement of non-perfect PSA for squeezed states with broad bandwidth for the measurement of weak absorption detection. Numerical calculations of the quantum advantage show that non-perfect PSA can effectively improve the inefficiency of detection in slight drift frequency detuning. © 2022 Optica Publishing Group.
  Accession Number: 20224513067987
• Record 347 of
  
  Title:Three-dimensional quantum droplets in spin-orbit-coupled Bose-Einstein condensates
  
  Author(s):Xu, Si-Liu(1); Lei, Yun-Bin(1); Du, Jin-Ting(1); Zhao, Yuan(1); Hua, Rui(2); Zeng, Jian-Hua(3)
  Source: Chaos, Solitons and Fractals  Volume: 164  Issue:   DOI: 10.1016/j.chaos.2022.112665  Published: November 2022  
  Abstract:Quantum droplets (QDs) are a recently discovered new state of matter in ultracold atoms. We study three-dimensional (3D) self-trapped modes in spinor Bose-Einstein condensates with spin-orbit coupling (SOC), described by coupled Gross-Pitaevskii equations including beyond-mean-field Lee-Huang-Yang terms. The 3D QDs, semi-vortex and mixed-mode states, of a large size with an anisotropic density profile, exist with a wide large values of the norm as the Lee-Huang-Yang terms eliminate the collapse. The effect of the intra- and inter-component of the nonlinearity and SOC on characteristics of the QDs is systematically addressed. Using the linear-stability analysis and direct simulations, we have checked the stability of all the 3D QDs states, stressing they are stable against small perturbations in propagation in limited scales. The present analysis opens a new way for creating multidimensional solitary waves, and may be developed in other directions, including nonlinear optics, not only in conservative, but also in dissipative systems. © 2022 Elsevier Ltd
  Accession Number: 20223812764504
• Record 348 of
  
  Title:Enatioselective Rotation of Chiral Particles by Azimuthally Polarized Beams
  
  Author(s):Li, Manman(1); Chen, Xu(1); Yan, Shaohui(1); Zhang, Yanan(1); Yao, Baoli(1,2)
  Source: Advanced Photonics Research  Volume: 3  Issue: 10  DOI: 10.1002/adpr.202200117  Published: October 2022  
  Abstract:The chirality-dependent forces can offer new possibilities for passive optical separation and identification of chiral particles, which opens great opportunities to develop the technologies of pharmaceutics, chemicals, and biomedicine. Here, a robust enantioselective rotation of subwavelength chiral particles using lateral optical forces induced by a tightly focused azimuthally polarized beam is demonstrated. Although this focused field carries neither optical orbital angular momentum nor optical chirality, the lateral optical force can rotate the particle with opposite chirality around opposite directions, achieving an effective optical enantioseparation. Such a counterintuitive phenomenon is closely related to the transformation of the magnetic spin angular momentum of the focused field into the mechanical orbital angular momentum of the particle. In addition, the particle with different chirality parameters will be trapped in different orbits while with opposite chirality trapped in the same orbit, meanwhile its rotation direction is determined by the sign of the chirality parameter, which can realize an efficient chiral identification of single particles. The investigations may open up a new path toward light-induced rotation or probing of objects with different chirality parameters. © 2022 The Authors. Advanced Photonics Research published by Wiley-VCH GmbH.
  Accession Number: 20233114476862