Optical metasurfaces have emerged as a groundbreaking technology in photonics,offering unparalleled control over light-matter interactions at the subwavelength scale with ultrathin surface nanostructures and thereby g...Optical metasurfaces have emerged as a groundbreaking technology in photonics,offering unparalleled control over light-matter interactions at the subwavelength scale with ultrathin surface nanostructures and thereby giving birth to flat optics.While most reported optical metasurfaces are static,featuring well-defined optical responses determined by their compositions and configurations set during fabrication,dynamic optical metasurfaces with reconfigurable functionalities by applying thermal,electrical,or optical stimuli have become increasingly more in demand and moved to the forefront of research and development.Among various types of dynamically controlled metasurfaces,electrically tunable optical metasurfaces have shown great promise due to their fast response time,low power consumption,and compatibility with existing electronic control systems,offering unique possibilities for dynamic tunability of light–matter interactions via electrical modulation.Here we provide a comprehensive overview of the state-of-the-art design methodologies and technologies explored in this rapidly evolving field.Our work delves into the fundamental principles of electrical modulation,various materials and mechanisms enabling tunability,and representative applications for active light-field manipulation,including optical amplitude and phase modulators,tunable polarization optics and wavelength filters,and dynamic waveshaping optics,including holograms and displays.The review terminates with our perspectives on the future development of electrically triggered optical metasurfaces.展开更多
The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical A1N/GaN coupled double quantum wells （CDQWs） has been investigated by solving SchrSdinger and Poisson equa...The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical A1N/GaN coupled double quantum wells （CDQWs） has been investigated by solving SchrSdinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition （ISBT） between the ground state and the third excited state （lodd - 2even） can be equal to zero when the electric fields are applied in asymmetrical A1N/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd - 2even and 1even - 2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical A1N/GaN CDQWs.展开更多
Stimulated Brillouin scattering （SBS） is a key problem with the increasing power of fiber transmission systems. In this letter, a frequency-modulated fiber laser with an ultra-narrow linewidth is chosen as a light s...Stimulated Brillouin scattering （SBS） is a key problem with the increasing power of fiber transmission systems. In this letter, a frequency-modulated fiber laser with an ultra-narrow linewidth is chosen as a light source. The SBS threshold is increased from 4.1 to 6.2 mW at 13-MHz frequency modulation amplitude for a 50-km G652 fiber. We also show that the SBS threshold increases with not only the frequency modulation amplitude, but also the modulation frequency. The modulation frequency should be high enough for effective modulation.展开更多
In this Letter, we propose an optical attenuator based on the phase modulation of a spatial light modulator （SLM）. In this system, we use two polarized beam splitters （PBSs） to control the polarized light and one ...In this Letter, we propose an optical attenuator based on the phase modulation of a spatial light modulator （SLM）. In this system, we use two polarized beam splitters （PBSs） to control the polarized light and one SLM to modulate the phase of the polarized light. In the initial state, the light beam is divided into p-light and s-light when it passes through the first PBS. When the light passes through the second PBS, s-light is reflected and p-light is detected by the CCD camera. By loading different grayscales on the SLM, p-light changes its polarized state to s-light. The light power can be attenuated during the loading process. Our experiment shows that the system can obtain a wide optical attenuation from 1-27.2 dB. When loading two grayscales, the SLM has a fast switching time of 25 ms under a low actuated voltage of 5.5 V. The response time of the optical attenuator depends on the switching time of the SLM. Therefore, the system can also have a fast response time. By using the method of spatial multiplexing and adding two mirrors in the system, it can also be extended into a 1 × 2 optical switch. The results verify its feasibility. The optical attenuator has wide applications in photonic signal processing and fiber-optic communication.展开更多
5G网络建设和大规模数据中心建设带来了大量光模块需求。在光模块生产制造中,为了保障光模块在环境温度变化情况下能够长时间正常工作,需要检测模块在不同温度下的性能,而进行高低温测试。高低温测试在光模块制造成本中占了很大比重。...5G网络建设和大规模数据中心建设带来了大量光模块需求。在光模块生产制造中,为了保障光模块在环境温度变化情况下能够长时间正常工作,需要检测模块在不同温度下的性能,而进行高低温测试。高低温测试在光模块制造成本中占了很大比重。设计了一种基于半导体制冷器(Thermo Electric Cooler)的光模块高低温测试系统,相较传统基于热流仪的方案,不需要压缩空气,能够大幅降低功耗、噪声和整体成本,且能够实现与热流仪相当的升降温时间。该系统对于节能减排、降低光模块制造成本有重要意义。展开更多
基金supported by the Independent Research Fund Denmark(No.1134-00010B)Villum Fonden(award in Technical and Natural Sciences 2019,Nos.37372 and 50343).
文摘Optical metasurfaces have emerged as a groundbreaking technology in photonics,offering unparalleled control over light-matter interactions at the subwavelength scale with ultrathin surface nanostructures and thereby giving birth to flat optics.While most reported optical metasurfaces are static,featuring well-defined optical responses determined by their compositions and configurations set during fabrication,dynamic optical metasurfaces with reconfigurable functionalities by applying thermal,electrical,or optical stimuli have become increasingly more in demand and moved to the forefront of research and development.Among various types of dynamically controlled metasurfaces,electrically tunable optical metasurfaces have shown great promise due to their fast response time,low power consumption,and compatibility with existing electronic control systems,offering unique possibilities for dynamic tunability of light–matter interactions via electrical modulation.Here we provide a comprehensive overview of the state-of-the-art design methodologies and technologies explored in this rapidly evolving field.Our work delves into the fundamental principles of electrical modulation,various materials and mechanisms enabling tunability,and representative applications for active light-field manipulation,including optical amplitude and phase modulators,tunable polarization optics and wavelength filters,and dynamic waveshaping optics,including holograms and displays.The review terminates with our perspectives on the future development of electrically triggered optical metasurfaces.
基金supported by the National Natural Science Foundation of China (Grant Nos 60806042,10774001,60736033,60890193 and 60628402)National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607)+1 种基金the Research Fund for the Doctoral Program of Higher Education in China (Grant Nos 200800011021 and 20060001018)Beijing Natural Science Foundation (Grant No 4062017)
文摘The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical A1N/GaN coupled double quantum wells （CDQWs） has been investigated by solving SchrSdinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition （ISBT） between the ground state and the third excited state （lodd - 2even） can be equal to zero when the electric fields are applied in asymmetrical A1N/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd - 2even and 1even - 2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical A1N/GaN CDQWs.
基金supported by the Program for New Century Excellent Talents in the University under Grant No. NCET-06-0925
文摘Stimulated Brillouin scattering （SBS） is a key problem with the increasing power of fiber transmission systems. In this letter, a frequency-modulated fiber laser with an ultra-narrow linewidth is chosen as a light source. The SBS threshold is increased from 4.1 to 6.2 mW at 13-MHz frequency modulation amplitude for a 50-km G652 fiber. We also show that the SBS threshold increases with not only the frequency modulation amplitude, but also the modulation frequency. The modulation frequency should be high enough for effective modulation.
基金supported by the National Natural Science Foundation of China(Nos.61225022and 61320106015)the National"973"Program of China(No.2013CB328802)the National"863"Program of China(Nos.2015AA015902 and 2012AA011901)
文摘In this Letter, we propose an optical attenuator based on the phase modulation of a spatial light modulator （SLM）. In this system, we use two polarized beam splitters （PBSs） to control the polarized light and one SLM to modulate the phase of the polarized light. In the initial state, the light beam is divided into p-light and s-light when it passes through the first PBS. When the light passes through the second PBS, s-light is reflected and p-light is detected by the CCD camera. By loading different grayscales on the SLM, p-light changes its polarized state to s-light. The light power can be attenuated during the loading process. Our experiment shows that the system can obtain a wide optical attenuation from 1-27.2 dB. When loading two grayscales, the SLM has a fast switching time of 25 ms under a low actuated voltage of 5.5 V. The response time of the optical attenuator depends on the switching time of the SLM. Therefore, the system can also have a fast response time. By using the method of spatial multiplexing and adding two mirrors in the system, it can also be extended into a 1 × 2 optical switch. The results verify its feasibility. The optical attenuator has wide applications in photonic signal processing and fiber-optic communication.
文摘5G网络建设和大规模数据中心建设带来了大量光模块需求。在光模块生产制造中,为了保障光模块在环境温度变化情况下能够长时间正常工作,需要检测模块在不同温度下的性能,而进行高低温测试。高低温测试在光模块制造成本中占了很大比重。设计了一种基于半导体制冷器(Thermo Electric Cooler)的光模块高低温测试系统,相较传统基于热流仪的方案,不需要压缩空气,能够大幅降低功耗、噪声和整体成本,且能够实现与热流仪相当的升降温时间。该系统对于节能减排、降低光模块制造成本有重要意义。
