An experimental platform for laser-induced cavitation under the action of an electric field was built, and the bubble pulsation under two different conditions of infinite domain and solid wall was experimentally studied. The effects of voltage, laser energy, and liquid viscosity on bubble pulsation and the difference in the effect of voltage on bubble induced by different laser energies and bubble pulsation in different viscous liquids were explored. It is found that the size, velocity and period of bubble pulsation in infinite domain increase with the increase of laser energy, and the law is similar at the solid wall. When the voltage is applied, the size and period of bubble pulsation in infinite domain decrease with the increase of voltage, the bubble expansion speed decreases with the increase of voltage, but the bubble collapse speed increases with the increase of voltage. The diameter and velocity of bubble pulsation in infinite domain decrease with the increase of liquid viscosity, while the whole pulsation period of bubble increases with the increase of viscosity. Due to the damping effect of liquid, the effect of electric field on the bubble pulsation with higher viscosity is low.
{"title":"Effect of electrical field on pulsation characteristics of laser-induced cavitation bubble","authors":"Jiayang Gu , Xiaohui Gu , Xuchen Zhang , Xuanming Liu , Xiaokang Luan","doi":"10.1016/j.optlastec.2024.112226","DOIUrl":"10.1016/j.optlastec.2024.112226","url":null,"abstract":"<div><div>An experimental platform for laser-induced cavitation under the action of an electric field was built, and the bubble pulsation under two different conditions of infinite domain and solid wall was experimentally studied. The effects of voltage, laser energy, and liquid viscosity on bubble pulsation and the difference in the effect of voltage on bubble induced by different laser energies and bubble pulsation in different viscous liquids were explored. It is found that the size, velocity and period of bubble pulsation in infinite domain increase with the increase of laser energy, and the law is similar at the solid wall. When the voltage is applied, the size and period of bubble pulsation in infinite domain decrease with the increase of voltage, the bubble expansion speed decreases with the increase of voltage, but the bubble collapse speed increases with the increase of voltage. The diameter and velocity of bubble pulsation in infinite domain decrease with the increase of liquid viscosity, while the whole pulsation period of bubble increases with the increase of viscosity. Due to the damping effect of liquid, the effect of electric field on the bubble pulsation with higher viscosity is low.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112226"},"PeriodicalIF":4.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.optlastec.2024.112187
Juan Deng , Kaili Wu , Rao Fu , Zhendong Huang , Chenchen Yang , Fan Gao , Bo Yan
As a novel optical element, metalens possess immense potential in the field of optical imaging. However, the development of full-space metalens, particularly those capable of manipulating normal and oblique incidence waves, remains challenging. By embedding 1D photonic crystal into a bilayer nanostructure, we proposed a full-space and wide field-of-view (FOV) metalens, which can independently manipulate reflected and transmitted waves in near-infrared (NIR) band. Simulation results demonstrate that our metalens can achieve good focusing effects in both the reflective and transmissive spaces at two different wavelengths under normal incidence. In addition, the metalens can still operate and maintain a good focusing effect at a wavelength of 1245 nm with an oblique incidence angle of −40° to 40°, at a wavelength of 1515 nm with an oblique incidence angle of −30° to 30°. Our work broadens the degree of freedom, establishes a connection between metasurfaces and photonic crystal, and provides an effective method for designing multifunctional meta-device, thereby demonstrating a huge applications potential in virtual reality (VR), augmented reality (AR) and other related fields.
{"title":"Full-space and wide field-of-view metalens based on 1D photonic crystal","authors":"Juan Deng , Kaili Wu , Rao Fu , Zhendong Huang , Chenchen Yang , Fan Gao , Bo Yan","doi":"10.1016/j.optlastec.2024.112187","DOIUrl":"10.1016/j.optlastec.2024.112187","url":null,"abstract":"<div><div>As a novel optical element, metalens possess immense potential in the field of optical imaging. However, the development of full-space metalens, particularly those capable of manipulating normal and oblique incidence waves, remains challenging. By embedding 1D photonic crystal into a bilayer nanostructure, we proposed a full-space and wide field-of-view (FOV) metalens, which can independently manipulate reflected and transmitted waves in near-infrared (NIR) band. Simulation results demonstrate that our metalens can achieve good focusing effects in both the reflective and transmissive spaces at two different wavelengths under normal incidence. In addition, the metalens can still operate and maintain a good focusing effect at a wavelength of 1245 nm with an oblique incidence angle of −40° to 40°, at a wavelength of 1515 nm with an oblique incidence angle of −30° to 30°. Our work broadens the degree of freedom, establishes a connection between metasurfaces and photonic crystal, and provides an effective method for designing multifunctional meta-device, thereby demonstrating a huge applications potential in virtual reality (VR), augmented reality (AR) and other related fields.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112187"},"PeriodicalIF":4.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.optlastec.2024.112211
Chaojun Huang , Xu Ma , Shengen Zhang , Mu Lin , Néstor Porras-Díaz , Gonzalo R. Arce
Inverse lithography technology (ILT) is a key computational lithography approach aimed at inversely optimizing the photomask pattern to compensate for the image distortion in advanced optical lithography process. Traditional ILT algorithms, despite their capacity of significantly enhancing the image quality, bring challenges to the computational efficiency and mask manufacturability. To overcome those problems, this paper proposes a novel block-based ILT method driven by the level-set algorithm. This method leverages overlapped basis blocks with a level-set support area for mask representation, thus reducing the mask complexity. To circumvent the slow convergence rate dictated by the conventional Euler time step of the Courant-Friedrichs-Lewy condition, this research adopts the Barzilai-Borwein algorithm to update level set function using adaptive time step, which accelerates the optimization process. In addition, a testbed of digital lithography system is established to verify the proposed ILT method with a calibrated imaging model. It shows that the proposed method is superior over the widely-used and state-of-the-art ILT methods in terms of convergence speed and mask manufacturability.
{"title":"Block-based inverse lithography technology with adaptive level-set algorithm","authors":"Chaojun Huang , Xu Ma , Shengen Zhang , Mu Lin , Néstor Porras-Díaz , Gonzalo R. Arce","doi":"10.1016/j.optlastec.2024.112211","DOIUrl":"10.1016/j.optlastec.2024.112211","url":null,"abstract":"<div><div>Inverse lithography technology (ILT) is a key computational lithography approach aimed at inversely optimizing the photomask pattern to compensate for the image distortion in advanced optical lithography process. Traditional ILT algorithms, despite their capacity of significantly enhancing the image quality, bring challenges to the computational efficiency and mask manufacturability. To overcome those problems, this paper proposes a novel block-based ILT method driven by the level-set algorithm. This method leverages overlapped basis blocks with a level-set support area for mask representation, thus reducing the mask complexity. To circumvent the slow convergence rate dictated by the conventional Euler time step of the Courant-Friedrichs-Lewy condition, this research adopts the Barzilai-Borwein algorithm to update level set function using adaptive time step, which accelerates the optimization process. In addition, a testbed of digital lithography system is established to verify the proposed ILT method with a calibrated imaging model. It shows that the proposed method is superior over the widely-used and state-of-the-art ILT methods in terms of convergence speed and mask manufacturability.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112211"},"PeriodicalIF":4.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.optlastec.2024.112112
Florian Pilat , Nikola Opačak , Sandro Dal Cin , Andreas Windischhofer , Etienne Giraud , Sargis Hakobyan , Richard Maulini , Antoine Muller , Pierre Jouy , Pitt Allmendinger , Benedikt Schwarz
The linewidth enhancement factor (LEF) of quantum cascade lasers (QCLs) is an important parameter, recently tightly linked to many phenomena that occur in this type of laser — from self-starting frequency combs to the emergence of solitons. The dynamic processes involved act at frequencies similar to the roundtrip frequency of the lasers (typically GHz), reflected in the high-frequency component of the LEF. Its value in QCLs is predicted to increase under laser operation with increasing light intensity, as the stronger gain saturation effectively increases the spectral gain asymmetry. Here, we investigate the hot-cavity LEF of a free-running frequency comb far above the laser threshold and at high frequencies, employing shifted wave interference Fourier transform spectroscopy (SWIFTS). Our measurements confirm an increasing LEF with laser current, which is supported by numerical simulations. From the spectral slope of the LEF we can extract further important parameters, such as the gain peak frequency and the decoherence time of the laser transition, which is tightly linked to the available gain bandwidth.
{"title":"Hot-cavity linewidth enhancement factor of a quantum cascade laser","authors":"Florian Pilat , Nikola Opačak , Sandro Dal Cin , Andreas Windischhofer , Etienne Giraud , Sargis Hakobyan , Richard Maulini , Antoine Muller , Pierre Jouy , Pitt Allmendinger , Benedikt Schwarz","doi":"10.1016/j.optlastec.2024.112112","DOIUrl":"10.1016/j.optlastec.2024.112112","url":null,"abstract":"<div><div>The linewidth enhancement factor (LEF) of quantum cascade lasers (QCLs) is an important parameter, recently tightly linked to many phenomena that occur in this type of laser — from self-starting frequency combs to the emergence of solitons. The dynamic processes involved act at frequencies similar to the roundtrip frequency of the lasers (typically GHz), reflected in the high-frequency component of the LEF. Its value in QCLs is predicted to increase under laser operation with increasing light intensity, as the stronger gain saturation effectively increases the spectral gain asymmetry. Here, we investigate the hot-cavity LEF of a free-running frequency comb far above the laser threshold and at high frequencies, employing shifted wave interference Fourier transform spectroscopy (SWIFTS). Our measurements confirm an increasing LEF with laser current, which is supported by numerical simulations. From the spectral slope of the LEF we can extract further important parameters, such as the gain peak frequency and the decoherence time of the laser transition, which is tightly linked to the available gain bandwidth.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112112"},"PeriodicalIF":4.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlastec.2024.112195
Xikui Mu , Bingzheng Yan , Jiashuo An , Hao Zheng , Yibo Qin , Yaoyao Qi , Jie Ding , Zhenxu Bai , Yulei Wang , Zhiwei Lu
Single-longitudinal-mode pulse lasers operating at a wavelength of 2 μm are extensively utilized as lidar light sources in gas detection applications. We demonstrated a tunable single-longitudinal-mode acousto-optic Q-switched Tm:YAP laser by a birefringent filter and etalon. With the absorbed pump power of 8.95 W, the laser achieved a pulse duration of 139 ns and a single pulse energy of 1.37 mJ at 1 kHz repetition rate, with an SLM ratio exceeding 99.5 %. The central wavelength was tunable over a wide range from 1887 nm to 2003 nm by adjusting the birefringent filter. Our results provide an effective approach for developing compact mid-infrared solid-state lasers with high power, wide tuning and excellent performance.
{"title":"Acousto-optic Q-switched broadband tunable single-longitudinal-mode 2 μm laser using a birefringent filter","authors":"Xikui Mu , Bingzheng Yan , Jiashuo An , Hao Zheng , Yibo Qin , Yaoyao Qi , Jie Ding , Zhenxu Bai , Yulei Wang , Zhiwei Lu","doi":"10.1016/j.optlastec.2024.112195","DOIUrl":"10.1016/j.optlastec.2024.112195","url":null,"abstract":"<div><div>Single-longitudinal-mode pulse lasers operating at a wavelength of 2 μm are extensively utilized as lidar light sources in gas detection applications. We demonstrated a tunable single-longitudinal-mode acousto-optic Q-switched Tm:YAP laser by a birefringent filter and etalon. With the absorbed pump power of 8.95 W, the laser achieved a pulse duration of 139 ns and a single pulse energy of 1.37 mJ at 1 kHz repetition rate, with an SLM ratio exceeding 99.5 %. The central wavelength was tunable over a wide range from 1887 nm to 2003 nm by adjusting the birefringent filter. Our results provide an effective approach for developing compact mid-infrared solid-state lasers with high power, wide tuning and excellent performance.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112195"},"PeriodicalIF":4.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlastec.2024.112176
Huiying Song , Long Huang , Feng Li , Shaoqing Zhao , Yuqing Liu , Yueting Liu , Ruizhan Zhai , Yongjun Dong , Zexin Feng , Hua Liu
Microlens arrays exhibit significant potential for applications in laser beam expansion, shaping, homogenization, and decoherence. Unfortunately, an increase in the target scattering angle of the microlens results in higher surface curvature. This can lead to a significant reduction in transmittance over a specific scattering angle range, directly affecting beam shaping and homogenization processes. In this paper, a design method for randomized microlens array homogenizing optical element with large scattering angles is proposed. A combination of transmission and total internal reflection (TIR) is used to significantly increase the scattering angle of the microlens arrays while maintaining high transmittance. A method of generating microlens arrays using random edge-length ratios is used to eliminate interference and improve the uniformity of the spot. The study explores the uniformity and energy utilization of random microlens arrays during random degree alteration and analyzes the influence of machining errors on homogenization. To validate the novel method, a random microlens array has been developed, featuring a scattering angle range of ± 41°, remarkable uniformity at 82.31 %, and an energy utilization rate of 85.48 %. This research lays a solid foundation for developing random microlens arrays with large scattering angles.
{"title":"Design of random microlens arrays with large scattering angles","authors":"Huiying Song , Long Huang , Feng Li , Shaoqing Zhao , Yuqing Liu , Yueting Liu , Ruizhan Zhai , Yongjun Dong , Zexin Feng , Hua Liu","doi":"10.1016/j.optlastec.2024.112176","DOIUrl":"10.1016/j.optlastec.2024.112176","url":null,"abstract":"<div><div>Microlens arrays exhibit significant potential for applications in laser beam expansion, shaping, homogenization, and decoherence. Unfortunately, an increase in the target scattering angle of the microlens results in higher surface curvature. This can lead to a significant reduction in transmittance over a specific scattering angle range, directly affecting beam shaping and homogenization processes. In this paper, a design method for randomized microlens array homogenizing optical element with large scattering angles is proposed. A combination of transmission and total internal reflection (TIR) is used to significantly increase the scattering angle of the microlens arrays while maintaining high transmittance. A method of generating microlens arrays using random edge-length ratios is used to eliminate interference and improve the uniformity of the spot. The study explores the uniformity and energy utilization of random microlens arrays during random degree alteration and analyzes the influence of machining errors on homogenization. To validate the novel method, a random microlens array has been developed, featuring a scattering angle range of ± 41°, remarkable uniformity at 82.31 %, and an energy utilization rate of 85.48 %. This research lays a solid foundation for developing random microlens arrays with large scattering angles.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112176"},"PeriodicalIF":4.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlastec.2024.112100
Qizhi Cai , Boyu Fan , Jin-Dao Tang , Hui Chen , Guangwei Deng
Exciton optomechanics, a hybrid platform facilitating nonlinear interactions among excitons, phonons, and photons, offers unique opportunities to explore light-matter interactions and their intrinsic nonlinearities. In this study, we propose a scheme to generate genuine tripartite entanglement among three exciton modes within an exciton-optomechanical system comprising a semiconductor optomechanical microcavity with three integrated quantum wells. The exciton modes supported by these quantum wells simultaneously interact with an optical cavity mode via a beam-splitter-type interaction and couple to a mechanical vibration mode through a nonlinear deformation potential interaction. By employing experimentally feasible parameters and carefully chosen detunings, the three exciton modes achieve resonance with the Stokes and anti-Stokes sidebands scattered by mechanical motion, enabling genuine tripartite entanglement. Notably, this steady-state entanglement is robust against thermal baths, providing a promising approach for generating excitonic multipartite entanglement.
{"title":"Genuine tripartite entanglement for exciton modes through exciton optomechanics","authors":"Qizhi Cai , Boyu Fan , Jin-Dao Tang , Hui Chen , Guangwei Deng","doi":"10.1016/j.optlastec.2024.112100","DOIUrl":"10.1016/j.optlastec.2024.112100","url":null,"abstract":"<div><div>Exciton optomechanics, a hybrid platform facilitating nonlinear interactions among excitons, phonons, and photons, offers unique opportunities to explore light-matter interactions and their intrinsic nonlinearities. In this study, we propose a scheme to generate genuine tripartite entanglement among three exciton modes within an exciton-optomechanical system comprising a semiconductor optomechanical microcavity with three integrated quantum wells. The exciton modes supported by these quantum wells simultaneously interact with an optical cavity mode via a beam-splitter-type interaction and couple to a mechanical vibration mode through a nonlinear deformation potential interaction. By employing experimentally feasible parameters and carefully chosen detunings, the three exciton modes achieve resonance with the Stokes and anti-Stokes sidebands scattered by mechanical motion, enabling genuine tripartite entanglement. Notably, this steady-state entanglement is robust against thermal baths, providing a promising approach for generating excitonic multipartite entanglement.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112100"},"PeriodicalIF":4.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlastec.2024.112097
N. Gusakova , A. Camper , R. Caravita , L. Penasa , L.T. Glöggler , T. Wolz , V. Krumins , F.P. Gustafsson , S. Huck , M. Volponi , B. Rienäcker , G. Khatri , J. Malamant , S. Mariazzi , R.S. Brusa , L. Cabaret , D. Comparat , M. Doser
We report on a Q-switched alexandrite based 100 ns long pulse duration ultra-violet laser system. The central wavelength of the fundamental pulse is set by a Volume Bragg Grating in reflection and can be tuned between 728 nm and 742 nm. The spectral bandwidth is 130 GHz. This laser system was designed in view of Doppler cooling of a cloud of a near room temperature positronium by strongly saturating the – transition. In addition, we report on the development of a KD*P Pockels cell driver designed to both Q-switch the cavity and induce a sharp falling edge of the laser pulse so that the end of the positronium-laser interaction time can be controlled with nanosecond precision.
{"title":"An alexandrite laser system for positronium laser cooling","authors":"N. Gusakova , A. Camper , R. Caravita , L. Penasa , L.T. Glöggler , T. Wolz , V. Krumins , F.P. Gustafsson , S. Huck , M. Volponi , B. Rienäcker , G. Khatri , J. Malamant , S. Mariazzi , R.S. Brusa , L. Cabaret , D. Comparat , M. Doser","doi":"10.1016/j.optlastec.2024.112097","DOIUrl":"10.1016/j.optlastec.2024.112097","url":null,"abstract":"<div><div>We report on a Q-switched alexandrite based <span><math><mo>∼</mo></math></span>100<!--> <!-->ns long pulse duration ultra-violet laser system. The central wavelength of the fundamental pulse is set by a Volume Bragg Grating in reflection and can be tuned between 728<!--> <!-->nm and 742<!--> <!-->nm. The spectral bandwidth is <span><math><mo>∼</mo></math></span>130<!--> <!-->GHz. This laser system was designed in view of Doppler cooling of a cloud of a near room temperature positronium by strongly saturating the <span><math><mrow><msup><mrow><mn>1</mn></mrow><mrow><mn>3</mn></mrow></msup><mtext>S</mtext></mrow></math></span>–<span><math><mrow><msup><mrow><mn>2</mn></mrow><mrow><mn>3</mn></mrow></msup><mtext>P</mtext></mrow></math></span> transition. In addition, we report on the development of a KD*P Pockels cell driver designed to both Q-switch the cavity and induce a sharp falling edge of the laser pulse so that the end of the positronium-laser interaction time can be controlled with nanosecond precision.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112097"},"PeriodicalIF":4.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlastec.2024.112183
Du Wang , Mingli Dong , Lianqing Zhu , Xiaoping Lou , Mingxin Yu , Yiqun Zhang , Chaofan Deng , Jingtao Xin , Yunhong Zhu , Kaiyuan Feng
In this paper, a compact and lightweight high-precision airborne fiber-optic strain sensor is designed, and a strain-load prediction model based on convolutional neural network and long short-term memory network (ConvLSTM) is proposed to validate the collected landing gear strain data. Firstly, based on the fiber Bragg grating (FBG) sensing principle and simulation validation, small and lightweight strain and temperature sensors were fabricated, and key performance parameters such as sensitivity and linearity were comprehensively investigated, and they were mounted on the left landing gear of the aircraft to conduct strain monitoring by loading a three-way load, and the ConvLSTM model was used to train and test the strain-load mapping with the maximum relative error, average relative error and variance as indicators to evaluate its prediction accuracy and stability. The experimental results show that the strain measurement accuracy is maintained within 2.5 % and the strain sensitivity is as high as 1.3 pm/με within the ± 5000 με measurement range of the strain sensor; the maximum relative errors of the X, Y, and Z load predictions are 6.03 %, 3.75 %, and 4.12 %, respectively, and the overall average relative errors are 2.38 %, 0.27 %, and 0.76 %, with variances of 0.23 N, 0.61 N, and 0.61 N, respectively. 0.23 N, 0.61 N and 0.12 N, indicating that the model predictions are stable and highly accurate, demonstrating higher prediction accuracy when compared with traditional multiple linear regression methods. The results of this research have important application value in the field of aircraft structural health monitoring.
{"title":"Application of fiber-optic strain sensing technology in high-precision load prediction of aircraft landing gear","authors":"Du Wang , Mingli Dong , Lianqing Zhu , Xiaoping Lou , Mingxin Yu , Yiqun Zhang , Chaofan Deng , Jingtao Xin , Yunhong Zhu , Kaiyuan Feng","doi":"10.1016/j.optlastec.2024.112183","DOIUrl":"10.1016/j.optlastec.2024.112183","url":null,"abstract":"<div><div>In this paper, a compact and lightweight high-precision airborne fiber-optic strain sensor is designed, and a strain-load prediction model based on convolutional neural network and long short-term memory network (ConvLSTM) is proposed to validate the collected landing gear strain data. Firstly, based on the fiber Bragg grating (FBG) sensing principle and simulation validation, small and lightweight strain and temperature sensors were fabricated, and key performance parameters such as sensitivity and linearity were comprehensively investigated, and they were mounted on the left landing gear of the aircraft to conduct strain monitoring by loading a three-way load, and the ConvLSTM model was used to train and test the strain-load mapping with the maximum relative error, average relative error and variance as indicators to evaluate its prediction accuracy and stability. The experimental results show that the strain measurement accuracy is maintained within 2.5 % and the strain sensitivity is as high as 1.3 pm/με within the ± 5000 με measurement range of the strain sensor; the maximum relative errors of the X, Y, and Z load predictions are 6.03 %, 3.75 %, and 4.12 %, respectively, and the overall average relative errors are 2.38 %, 0.27 %, and 0.76 %, with variances of 0.23 N, 0.61 N, and 0.61 N, respectively. 0.23 N, 0.61 N and 0.12 N, indicating that the model predictions are stable and highly accurate, demonstrating higher prediction accuracy when compared with traditional multiple linear regression methods. The results of this research have important application value in the field of aircraft structural health monitoring.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112183"},"PeriodicalIF":4.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.optlastec.2024.112208
Maryam Imani
Hyperspectral target detection is one of the main applications in remote sensing field, which has several challenges such as imbalance between target and background and how accurately separate targets from background. To deal with these difficulties, the discriminant analysis-based attention network (DAAN) is proposed in this work. To solve the insufficient number of targets, two autoencoder based data augmentation approaches, which are pixel-based and patch-based are suggested. While the augmented target pixels are used for feature space transformation for maximizing the between-class scatters and minimizing the within-class scatters, the augmented target patches are used as input of the network. To increase the separability among targets and background, a discriminant analysis method is introduced. An attention feature map is generated from the discriminant analysis for weighting the feature maps of the proposed network to highlight targets with respect to the background. DAAN uses the low-level features attended by the weight matrix in addition to the high-level features hierarchically extracted by several convolutional kernels. The experiments show high detection performance of DAAN in various hyperspectral images where there is no need to set the free parameters for each dataset.
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