传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。...传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。通过构建三角形晶格光子晶体平板,在晶胞内引入圆柱型蚀刻孔实现对称性保护,并采用理想磁导体边界条件分离TE模式,将连续域束缚态(bound states in the continuum,BIC)的拓扑保护机制引入THz频段。结果显示,Γ点处Q因子达到1010量级,且BIC位于远场辐射的偏振涡旋中心,验证了BIC机制及其拓扑特性,仿真结果良好。最终实现的Q因子较传统器件提升了多个数量级,且拓扑保护机制可以显著抑制加工缺陷与环境扰动对谐振性能的影响,为低损耗通信器件、光学可编程技术与量子光源设计提供了新范式。展开更多
In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep le...In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep learning has focused on single-layer grating couplers,and the accuracy of multi-layer grating couplers has not yet reached a high level.This paper proposes and demonstrates a novel deep learning network-assisted strategy for inverse design.The network model is based on a multi-layer perceptron(MLP)and incorporates convolutional neural networks(CNNs)and transformers.Through the stacking of multiple layers,it achieves a high-precision design for both multi-layer and single-layer raster couplers with various functionalities.The deep learning network exhibits exceptionally high predictive accuracy,with an average absolute error across the full wavelength range of 1300–1700 nm being only 0.17%,and an even lower predictive absolute error below 0.09%at the specific wavelength of 1550 nm.By combining the deep learning network with the genetic algorithm,we can efficiently design grating couplers that perform different functions.Simulation results indicate that the designed single-wavelength grating couplers achieve coupling efficiencies exceeding 80%at central wavelengths of 1550 nm and 1310 nm.The performance of designed dual-wavelength and broadband grating couplers also reaches high industry standards.Furthermore,the network structure and inverse design method are highly scalable and can be applied not only to multi-layer grating couplers but also directly to the prediction and design of single-layer grating couplers,providing a new perspective for the innovative development of photonic devices.展开更多
文摘传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。通过构建三角形晶格光子晶体平板,在晶胞内引入圆柱型蚀刻孔实现对称性保护,并采用理想磁导体边界条件分离TE模式,将连续域束缚态(bound states in the continuum,BIC)的拓扑保护机制引入THz频段。结果显示,Γ点处Q因子达到1010量级,且BIC位于远场辐射的偏振涡旋中心,验证了BIC机制及其拓扑特性,仿真结果良好。最终实现的Q因子较传统器件提升了多个数量级,且拓扑保护机制可以显著抑制加工缺陷与环境扰动对谐振性能的影响,为低损耗通信器件、光学可编程技术与量子光源设计提供了新范式。
基金sponsored by the National Key Scientific Instrument and Equipment Development Projects of China(Grant No.62027823)the National Natural Science Foun-dation of China(Grant No.61775048).
文摘In recent years,the use of deep learning to replace traditional numerical methods for electromagnetic propagation has shown tremendous potential in the rapid design of photonic devices.However,most research on deep learning has focused on single-layer grating couplers,and the accuracy of multi-layer grating couplers has not yet reached a high level.This paper proposes and demonstrates a novel deep learning network-assisted strategy for inverse design.The network model is based on a multi-layer perceptron(MLP)and incorporates convolutional neural networks(CNNs)and transformers.Through the stacking of multiple layers,it achieves a high-precision design for both multi-layer and single-layer raster couplers with various functionalities.The deep learning network exhibits exceptionally high predictive accuracy,with an average absolute error across the full wavelength range of 1300–1700 nm being only 0.17%,and an even lower predictive absolute error below 0.09%at the specific wavelength of 1550 nm.By combining the deep learning network with the genetic algorithm,we can efficiently design grating couplers that perform different functions.Simulation results indicate that the designed single-wavelength grating couplers achieve coupling efficiencies exceeding 80%at central wavelengths of 1550 nm and 1310 nm.The performance of designed dual-wavelength and broadband grating couplers also reaches high industry standards.Furthermore,the network structure and inverse design method are highly scalable and can be applied not only to multi-layer grating couplers but also directly to the prediction and design of single-layer grating couplers,providing a new perspective for the innovative development of photonic devices.
