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Optical Devices|1172 Article(s)
Parameter Identification of the MEMS Micromirror Model Based on Improved Least Squares Method
Zirui Wang, Zhihui Feng, Ming Lei, and Ze Wu
Aiming at the problem of establishing the mathematical model of the electromagnetic-driven micro-electro-mechanical system (MEMS) micromirror applied to the laser radar, the discrete model of the electromagnetic-driven MEMS micromirror is established by combining the mechanism analysis method with the input-output method. A recursive least squares method with variable forgetting factor is proposed to identify the model parameters of electromagnetic-driven MEMS micromirror. By making the forgetting factor dynamic, the problem of "data saturation" is solved, so that as much input and output data as possible can play a role in parameter identification, and the accuracy of parameter identification is improved. Through the simulation and experimental verification of this method, the results show that the error of the model obtained by recursive least squares identification with variable forgetting factor is reduced by 9.2% compared with traditional recursive least squares identification. Aiming at the problem of establishing the mathematical model of the electromagnetic-driven micro-electro-mechanical system (MEMS) micromirror applied to the laser radar, the discrete model of the electromagnetic-driven MEMS micromirror is established by combining the mechanism analysis method with the input-output method. A recursive least squares method with variable forgetting factor is proposed to identify the model parameters of electromagnetic-driven MEMS micromirror. By making the forgetting factor dynamic, the problem of "data saturation" is solved, so that as much input and output data as possible can play a role in parameter identification, and the accuracy of parameter identification is improved. Through the simulation and experimental verification of this method, the results show that the error of the model obtained by recursive least squares identification with variable forgetting factor is reduced by 9.2% compared with traditional recursive least squares identification.
Laser & Optoelectronics Progress
- Publication Date: May. 10, 2024
- Vol. 61, Issue 9, 0923002 (2024)
Design and Implementation of Real-Time Fluorescence Triple Correlation Spectroscopy Correlator Based on FPGA
Yanan Sun, Ping Cai, Weida Wang, Xinwei Lu, Chaoqing Dong, and Jicun Ren
To meet the requirements of multichannel fluorescence correlation spectroscopy with a wide dynamic range, a digital correlator based on field programmable gate array (FPGA) technology was designed and implemented. The hardware structure was designed and implemented using a register-level hardware description language. Based on the characteristics of photon pulse counting signals, the multi-sampling-time correlation and time-division multiplexing methods were used to calculate the correlation function, which substantially improved computing efficiency and optimized hardware resource utilization. The time-division multiplexing of cross correlation was extended to triple correlation, and the corresponding method was extended to adapt triple correlation. Ultimately, a real-time computing triple correlator based on FPGA was realized. The calculation method of symmetric normalization ensured the accuracy of the correlation function. The designed photon correlator was implemented based on a single Xilinx Zynq-7100 FPGA chip, which performed various functions, including the real-time correlation of three channels auto-correlation, three channels cross-correlation, and one channel triple correlation, with the time resolution of 40 ns and dynamic range of 1.57 × 107. To meet the requirements of multichannel fluorescence correlation spectroscopy with a wide dynamic range, a digital correlator based on field programmable gate array (FPGA) technology was designed and implemented. The hardware structure was designed and implemented using a register-level hardware description language. Based on the characteristics of photon pulse counting signals, the multi-sampling-time correlation and time-division multiplexing methods were used to calculate the correlation function, which substantially improved computing efficiency and optimized hardware resource utilization. The time-division multiplexing of cross correlation was extended to triple correlation, and the corresponding method was extended to adapt triple correlation. Ultimately, a real-time computing triple correlator based on FPGA was realized. The calculation method of symmetric normalization ensured the accuracy of the correlation function. The designed photon correlator was implemented based on a single Xilinx Zynq-7100 FPGA chip, which performed various functions, including the real-time correlation of three channels auto-correlation, three channels cross-correlation, and one channel triple correlation, with the time resolution of 40 ns and dynamic range of 1.57 × 107.
Laser & Optoelectronics Progress
- Publication Date: May. 10, 2024
- Vol. 61, Issue 9, 0923001 (2024)
Design and Research on a Reconfigurable Microwave Photonic Mixer
Yishi Han, Xian Li, Yongming Zhong, and Changsheng Zeng
A design and research scheme for a reconfigurable microwave photonic mixer is proposed. The scheme can reconstruct and generate a linear frequency modulation signal, a frequency conversion signal, or a phase shift signal only by changing the driving signal and direct-current bias voltage. The generated linear frequency-modulated signal has three bands, and the bandwidth can be increased to four times at most. Up and down conversion signals can be generated at the same time. The obtained phase shift signal can be continuously tuned at 0?360°. The simulation results show that the scheme can generate linear frequency-modulated signals with a frequency of 11 GHz and a bandwidth of 2 GHz, a frequency of 18 GHz and a bandwidth of 4 GHz, and a frequency of 29 GHz and a bandwidth of 2 GHz. The pulse compression performance is good. It can simultaneously generate an up-conversion signal with a frequency of 32 GHz and a down-conversion signal with a frequency of 8 GHz, and the electric stray suppression ratio is higher than 30 dB. It can also generate a continuously adjustable phase-shift signal with a 0?360° phase, and the power fluctuation is within 0.1 dB. The system has a spurious free dynamic range of 114.1 dB?Hz2/3. A design and research scheme for a reconfigurable microwave photonic mixer is proposed. The scheme can reconstruct and generate a linear frequency modulation signal, a frequency conversion signal, or a phase shift signal only by changing the driving signal and direct-current bias voltage. The generated linear frequency-modulated signal has three bands, and the bandwidth can be increased to four times at most. Up and down conversion signals can be generated at the same time. The obtained phase shift signal can be continuously tuned at 0?360°. The simulation results show that the scheme can generate linear frequency-modulated signals with a frequency of 11 GHz and a bandwidth of 2 GHz, a frequency of 18 GHz and a bandwidth of 4 GHz, and a frequency of 29 GHz and a bandwidth of 2 GHz. The pulse compression performance is good. It can simultaneously generate an up-conversion signal with a frequency of 32 GHz and a down-conversion signal with a frequency of 8 GHz, and the electric stray suppression ratio is higher than 30 dB. It can also generate a continuously adjustable phase-shift signal with a 0?360° phase, and the power fluctuation is within 0.1 dB. The system has a spurious free dynamic range of 114.1 dB?Hz2/3.
Laser & Optoelectronics Progress
- Publication Date: Mar. 10, 2024
- Vol. 61, Issue 5, 0523003 (2024)
AlGaN-Based Deep-UV LED with Novel Transparent Electrodes and Integrated Array Device for Efficient Disinfection
Zefeng Lin, Lucheng Yu, Qicheng Zhou, Yehang Cai, Fawen Su, Shengrong Huang, Feiya Xu, Xiaohong Chen, Ling Li, and Duanjun Cai
The COVID-19 pandemic since 2019 has brought huge impacts and economic losses to the world. AlGaN-based deep-ultraviolet light emitting diode (DUV-LED) as a new and efficient sterilization device has attracted broad research attentions. The transparent electrode covering deep-UV band plays an important role in improving the performance of deep-UV LEDs. Here, we propose a novel core-shell structure Cu@metal nanosilks (Cu@metal NSs) network electrode with high transparency (>90%) to enhance the output power of deep-UV LED. In addition, based on the optimized design of integrated array module of deep-UV LEDs, a 180 mW DUV-LED sterilization device is fabricated. The device shows high inactivation performance for Escherichia coli and Staphylococcus aureus (>99.99%) and for COVID-19 virus (>99.9%). This work provides a novel method for improving the performance of deep-UV LEDs and pushing forward the efficient sterilization applications. The COVID-19 pandemic since 2019 has brought huge impacts and economic losses to the world. AlGaN-based deep-ultraviolet light emitting diode (DUV-LED) as a new and efficient sterilization device has attracted broad research attentions. The transparent electrode covering deep-UV band plays an important role in improving the performance of deep-UV LEDs. Here, we propose a novel core-shell structure Cu@metal nanosilks (Cu@metal NSs) network electrode with high transparency (>90%) to enhance the output power of deep-UV LED. In addition, based on the optimized design of integrated array module of deep-UV LEDs, a 180 mW DUV-LED sterilization device is fabricated. The device shows high inactivation performance for Escherichia coli and Staphylococcus aureus (>99.99%) and for COVID-19 virus (>99.9%). This work provides a novel method for improving the performance of deep-UV LEDs and pushing forward the efficient sterilization applications.
Laser & Optoelectronics Progress
- Publication Date: Mar. 10, 2024
- Vol. 61, Issue 5, 0523002 (2024)
Lithium Niobate Waveguide Mode Converter Based on V-Shaped Silicon
Cheng Zhang, Yin Xu, Yue Dong, Bo Zhang, and Yi Ni
Mode converter, achieving the mode conversion task from fundamental mode to higher-order mode, is a key component for the on-chip multimode transmission and mode division multiplexing transmission. Here, we propose an array of V-shaped silicon mode converter based on the thin film lithium niobate (TFLN) waveguide. The mode conversion structure is consisted of an array of V-shaped silicon, where it is deposited atop the TFLN waveguide. Based on such structure, we conduct detailed structural analyses and optimizations, where the required conversion length is only 11 μm and the central wavelength is 1550 nm for the mode conversion from input TE0 mode to output TE1 mode. The mode conversion efficiency, crosstalk, and insertion loss are 96.8%, -28.6 dB, and 0.78 dB, respectively. We further extend the device structure and obtain the mode conversion from input TE0 mode to output TE2 mode in the same length, where the mode conversion efficiency, crosstalk, and insertion loss are 91.3%, -?14.3 dB, and 1 dB, respectively. If we further extend the device structure, other higher-order modes can also be obtained. We believe the proposed device structure and scheme could benefit the multimode transmission for the TFLN waveguide and boost the development of photonic integrated components and circuits based on the TFLN platform. Mode converter, achieving the mode conversion task from fundamental mode to higher-order mode, is a key component for the on-chip multimode transmission and mode division multiplexing transmission. Here, we propose an array of V-shaped silicon mode converter based on the thin film lithium niobate (TFLN) waveguide. The mode conversion structure is consisted of an array of V-shaped silicon, where it is deposited atop the TFLN waveguide. Based on such structure, we conduct detailed structural analyses and optimizations, where the required conversion length is only 11 μm and the central wavelength is 1550 nm for the mode conversion from input TE0 mode to output TE1 mode. The mode conversion efficiency, crosstalk, and insertion loss are 96.8%, -28.6 dB, and 0.78 dB, respectively. We further extend the device structure and obtain the mode conversion from input TE0 mode to output TE2 mode in the same length, where the mode conversion efficiency, crosstalk, and insertion loss are 91.3%, -?14.3 dB, and 1 dB, respectively. If we further extend the device structure, other higher-order modes can also be obtained. We believe the proposed device structure and scheme could benefit the multimode transmission for the TFLN waveguide and boost the development of photonic integrated components and circuits based on the TFLN platform.
Laser & Optoelectronics Progress
- Publication Date: Mar. 10, 2024
- Vol. 61, Issue 5, 0523001 (2024)
Polarity-Controllable Laser-Processed Graphene Oxide-Based Memristor (Invited)
Suling Liu, Zhengfen Wan, Yutian Wang, Min Gu, and Qiming Zhang
In recent years, neuromorphic computing, inspired by the structure and function of biological nervous systems, has gained substantial attention. Memristors, which are capable of modulating conductivity via electric charge or magnetic flux, mimic synaptic interactions in the human brain, making them promising candidates for neuromorphic computing. This study proposes a method using femtosecond laser-processed graphene oxide memristors. Adjusting the scanning voltage at both device ends achieves polarity-controlled resistance switching. The device exhibits unipolar resistance switching at low voltages and stability over 150 cycles with a power consumption of only 0.75 nW. At higher voltages, bipolar switching occurs with increased conductivity over the test cycles. This study explores switching mechanisms under two voltage conditions, thus providing a comprehensive understanding of these mechanisms. This innovative approach using femtosecond laser-processed graphene oxide memristors shows promise for neuromorphic computing, offering efficient performance, stability, and adaptability across voltage scenarios. In recent years, neuromorphic computing, inspired by the structure and function of biological nervous systems, has gained substantial attention. Memristors, which are capable of modulating conductivity via electric charge or magnetic flux, mimic synaptic interactions in the human brain, making them promising candidates for neuromorphic computing. This study proposes a method using femtosecond laser-processed graphene oxide memristors. Adjusting the scanning voltage at both device ends achieves polarity-controlled resistance switching. The device exhibits unipolar resistance switching at low voltages and stability over 150 cycles with a power consumption of only 0.75 nW. At higher voltages, bipolar switching occurs with increased conductivity over the test cycles. This study explores switching mechanisms under two voltage conditions, thus providing a comprehensive understanding of these mechanisms. This innovative approach using femtosecond laser-processed graphene oxide memristors shows promise for neuromorphic computing, offering efficient performance, stability, and adaptability across voltage scenarios.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0323002 (2024)
Metasurfaces for Manipulating and Controlling Visible-Light Emission and Its Diverse Applications (Invited)
Shaojun Wang, Zhenghe Zhang, Ziyue Hou, Yiheng Zhai, Chaojie Xu, and Xiaofeng Li
Artificially constructed planar metasurfaces play a crucial role in photonics and emerging optoelectronic technologies due to their unique electromagnetic characteristics, ultrathin profiles, and seamless integration capabilities. Light-emitting metasurfaces based on near-field resonance modes exhibit unique advantages in scattering radiative photons, directing and enhancing light emission, expanding their applications in advanced photonics. This review provides an insightful overview of the basic principles of manipulating and controlling the emission behavior of ensembled quantum emitters, and provides a detailed introduction to the latest research and application progress of light-emitting metasurfaces within the visible light spectrum, including applications in fields such as miniature solid-state lighting devices, virtual reality and augmented reality high-definition displays, visible light communication, high-energy X-ray detection, chiral light-sources, and low threshold micro/nano lasers, etc. Finally, future development directions of light-emitting metasurfaces are prospected. Artificially constructed planar metasurfaces play a crucial role in photonics and emerging optoelectronic technologies due to their unique electromagnetic characteristics, ultrathin profiles, and seamless integration capabilities. Light-emitting metasurfaces based on near-field resonance modes exhibit unique advantages in scattering radiative photons, directing and enhancing light emission, expanding their applications in advanced photonics. This review provides an insightful overview of the basic principles of manipulating and controlling the emission behavior of ensembled quantum emitters, and provides a detailed introduction to the latest research and application progress of light-emitting metasurfaces within the visible light spectrum, including applications in fields such as miniature solid-state lighting devices, virtual reality and augmented reality high-definition displays, visible light communication, high-energy X-ray detection, chiral light-sources, and low threshold micro/nano lasers, etc. Finally, future development directions of light-emitting metasurfaces are prospected.
Laser & Optoelectronics Progress
- Publication Date: Feb. 10, 2024
- Vol. 61, Issue 3, 0323001 (2024)
Efficient Photoelectric Coupling Simulation and Machine Learning Study of Perovskite Solar Cells (Invited)
Ruiying Kong, Yijun Wei, Jiacheng Chen, Tianshu Ma, Yaohui Zhan, and Xiaofeng Li
In recent years, perovskite solar cells (PSCs) have attracted much attention because of their remarkable advantages in power conversion efficiency and manufacturing cost. However, their complex physical mechanisms and numerous constraints pose challenges to experimental design, process fabrication, and comprehensive optimization strategies. Here, we carried out a series of multi-physical field simulations with the optoelectronic multi-physical field coupling model as the core, and studied the underlying physics and boundary conditions of the optoelectronic coupling model, and then obtained a large amount of data on the optical and electrical properties of PSCs. Based on these data, we established the machine learning models and neural network models for the micro physical quantities and macro photoelectric responses, which predicted the performance of PSCs with an error of less than 3% in a fast speed. Combined with the genetic algorithm, the model reversely optimized the structural parameters according to the given response curves to obtain the more efficient PSCs. This study effectively solves the problem that PSCs are difficult to optimize design due to complex photoelectric coupling mechanism, numerous physical property parameters and slow simulation speed, and provides a feasible path for rapid and intelligent design of photovoltaic devices. In recent years, perovskite solar cells (PSCs) have attracted much attention because of their remarkable advantages in power conversion efficiency and manufacturing cost. However, their complex physical mechanisms and numerous constraints pose challenges to experimental design, process fabrication, and comprehensive optimization strategies. Here, we carried out a series of multi-physical field simulations with the optoelectronic multi-physical field coupling model as the core, and studied the underlying physics and boundary conditions of the optoelectronic coupling model, and then obtained a large amount of data on the optical and electrical properties of PSCs. Based on these data, we established the machine learning models and neural network models for the micro physical quantities and macro photoelectric responses, which predicted the performance of PSCs with an error of less than 3% in a fast speed. Combined with the genetic algorithm, the model reversely optimized the structural parameters according to the given response curves to obtain the more efficient PSCs. This study effectively solves the problem that PSCs are difficult to optimize design due to complex photoelectric coupling mechanism, numerous physical property parameters and slow simulation speed, and provides a feasible path for rapid and intelligent design of photovoltaic devices.
Laser & Optoelectronics Progress
- Publication Date: Jan. 10, 2024
- Vol. 61, Issue 1, 0123002 (2024)
Research Progress of Metasurface-Based Jones Matrix Modulation (Invited)
Chao Feng, Tao He, Yuzhi Shi, Zhanshan Wang, and Xinbin Cheng
Polarization, a fundamental degree of freedom of the optical field, has important applications in many fields of optical technology. The optical field modulation performance of optical devices is often expressed by the Jones matrix with its number of controllable channels characterizing the polarization control capability. With the rapid development of optical technology, novel applications, such as polarization imaging, information coding, and optical encryption, require optical devices to independently modulate multiple Jones-matrix channels while considering the need for miniaturization. Metasurface, a planar optical device composed of artificial subwavelength nano-structures with specific order, is expected to have a greater role in the field of polarization optics devices owing to its natural advantage of integration and powerful ability to modulate electromagnetic waves with arbitrary customization. In this paper, we first introduce the phase and amplitude modulation mechanisms of the metasurfaces, then systematically review the development of Jones matrix modulated metasurfaces with an increase in the number of controllable channels, and finally, provide an outlook on the future development of Jones matrix modulation technology for metasurfaces. Polarization, a fundamental degree of freedom of the optical field, has important applications in many fields of optical technology. The optical field modulation performance of optical devices is often expressed by the Jones matrix with its number of controllable channels characterizing the polarization control capability. With the rapid development of optical technology, novel applications, such as polarization imaging, information coding, and optical encryption, require optical devices to independently modulate multiple Jones-matrix channels while considering the need for miniaturization. Metasurface, a planar optical device composed of artificial subwavelength nano-structures with specific order, is expected to have a greater role in the field of polarization optics devices owing to its natural advantage of integration and powerful ability to modulate electromagnetic waves with arbitrary customization. In this paper, we first introduce the phase and amplitude modulation mechanisms of the metasurfaces, then systematically review the development of Jones matrix modulated metasurfaces with an increase in the number of controllable channels, and finally, provide an outlook on the future development of Jones matrix modulation technology for metasurfaces.
Laser & Optoelectronics Progress
- Publication Date: Jan. 10, 2024
- Vol. 61, Issue 1, 0123001 (2024)
Goos-Hänchen Shifts of Metal Layer and Quasicrystals with Monolayer Graphene
Zhengyang Li, Haixia Da, and Xiaohong Yan
Since the magnitudes of the Goos-H?nchen (GH) shifts in multilayered photonic crystals are generally small, it is desirable to find the alternative configurations to achieve the large GH shift. In this work, we investigated the GH shift of the reflected wave in the structure with a metal layer, a dielectric material, and the quasiperiodic photonic crystal by the transfer matrix method, where the quasiperiodic photonic crystal is composed of a dielectric material and monolayer graphene arranged in a Fibonacci sequence. It is found that the GH shift can be enhanced up to 7330 times of the incident wavelength at the specified operating wavelength 2 μm due to the excitation of surface plasmon polaritons of metal. In addition, we discussed the influence of the optical parameters of monolayer graphene, and the thickness of the dielectric material on the GH shift, and confirmed that changing these parameters could achieve the control of GH shift. Since the magnitudes of the Goos-H?nchen (GH) shifts in multilayered photonic crystals are generally small, it is desirable to find the alternative configurations to achieve the large GH shift. In this work, we investigated the GH shift of the reflected wave in the structure with a metal layer, a dielectric material, and the quasiperiodic photonic crystal by the transfer matrix method, where the quasiperiodic photonic crystal is composed of a dielectric material and monolayer graphene arranged in a Fibonacci sequence. It is found that the GH shift can be enhanced up to 7330 times of the incident wavelength at the specified operating wavelength 2 μm due to the excitation of surface plasmon polaritons of metal. In addition, we discussed the influence of the optical parameters of monolayer graphene, and the thickness of the dielectric material on the GH shift, and confirmed that changing these parameters could achieve the control of GH shift.
Laser & Optoelectronics Progress
- Publication Date: May. 10, 2023
- Vol. 60, Issue 9, 0923001 (2023)
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