The asymmetric imaging device is a crucial and highly desired component in optical and electromagnetic systems.However,most existing asymmetric imaging devices are based on active or nonlinear materials and are limite...The asymmetric imaging device is a crucial and highly desired component in optical and electromagnetic systems.However,most existing asymmetric imaging devices are based on active or nonlinear materials and are limited to one-directional applications.This paper reports a method to realize asymmetric image transmission and transformation in two opposite directions,respectively,based on diffractive deep neural networks(D^(2)NNs),named Janus meta-imager.It is a passive device composed of several diffractive layers that are well-trained using deep-learning-based algorithms.We first experimentally fabricate and validate this Janus meta-imager in the near-infrared(NIR)band,which agrees well with simulation results,thus verifying the asymmetric imaging function.This scheme has the merits of high-speed all-optical processing,low energy consumption,and small size,offering potential applications in all-optical encryption and information storage.展开更多
In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor...In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor unit up to 50) is studied to develop design limitations and to evaluate their effects on the device performance. We have also investigated the impact of the number of fins (up to 50) in multi-fin structure and resulting RF parameters. Our results show that as the number of fin increases, underlap design compromises RF performance and short channel effects. The results provide technical understanding that is necessary to realize new opportunities for RF and analog mixed-signal design with nanoscale FinFETs.展开更多
The beam splitter is one of the most crucial components in optical and electromagnetic systems,and it is also expected to be applied in terahertz(THz)technology.However,most existing beam splitters operate in only a s...The beam splitter is one of the most crucial components in optical and electromagnetic systems,and it is also expected to be applied in terahertz(THz)technology.However,most existing beam splitters operate in only a single working mode,restricting their applications.This paper reports a method for the inverse design of a doublet meta-device consisting of two stacked metasurfaces functioning as a reconfigurable THz beam splitter.It is made of photo-curable high-temperature resin using 3D printing technology.By simply adjusting the relative rotation angles between the two metasurfaces to 0°,90°,180°,and 270°,the meta-device can produce four distinct focal patterns,thus achieving four different working modes.This scheme avoids introducing complicated active components,offering a simple,low-cost design of a signal divider in future 6G THz communication systems.展开更多
基金funded by the National Key R&D Program of China(No.2021YFA1401200)National Natural Science Foundation of China(Nos.62231001 and U21A20140)Beijing Natural Science Foundation(No.JQ24028).
文摘The asymmetric imaging device is a crucial and highly desired component in optical and electromagnetic systems.However,most existing asymmetric imaging devices are based on active or nonlinear materials and are limited to one-directional applications.This paper reports a method to realize asymmetric image transmission and transformation in two opposite directions,respectively,based on diffractive deep neural networks(D^(2)NNs),named Janus meta-imager.It is a passive device composed of several diffractive layers that are well-trained using deep-learning-based algorithms.We first experimentally fabricate and validate this Janus meta-imager in the near-infrared(NIR)band,which agrees well with simulation results,thus verifying the asymmetric imaging function.This scheme has the merits of high-speed all-optical processing,low energy consumption,and small size,offering potential applications in all-optical encryption and information storage.
文摘In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor unit up to 50) is studied to develop design limitations and to evaluate their effects on the device performance. We have also investigated the impact of the number of fins (up to 50) in multi-fin structure and resulting RF parameters. Our results show that as the number of fin increases, underlap design compromises RF performance and short channel effects. The results provide technical understanding that is necessary to realize new opportunities for RF and analog mixed-signal design with nanoscale FinFETs.
基金National Natural Science Foundation of China(62231001)Hong Kong Research Grants Council Collaborative Research Fund(C1009-22G)。
文摘The beam splitter is one of the most crucial components in optical and electromagnetic systems,and it is also expected to be applied in terahertz(THz)technology.However,most existing beam splitters operate in only a single working mode,restricting their applications.This paper reports a method for the inverse design of a doublet meta-device consisting of two stacked metasurfaces functioning as a reconfigurable THz beam splitter.It is made of photo-curable high-temperature resin using 3D printing technology.By simply adjusting the relative rotation angles between the two metasurfaces to 0°,90°,180°,and 270°,the meta-device can produce four distinct focal patterns,thus achieving four different working modes.This scheme avoids introducing complicated active components,offering a simple,low-cost design of a signal divider in future 6G THz communication systems.
