In recent years, wave-based analog computing has been at the center of attention for providing ultra-fast and power-efficient signal processing enabled by wave propagation through artificially engineered structures. Building on these structures, various proposals have been put forward for performing computations with waves. Most of these proposals have been aimed at linear operations, such as vector-matrix multiplications. The weak and hardly controllable nonlinear response of electromagnetic materials imposes challenges in the design of wave-based structures for performing nonlinear operations. In the present work, first, by using the method of inverse design we propose a three-port device, which consists of a combination of linear and Kerr nonlinear materials, exhibiting the desired power-dependent transmission properties. Then, combining a proper arrangement of such devices with a collection of Mach-Zehnder interferometers (MZIs), we propose a reconfigurable nonlinear optical architecture capable of implementing a variety of nonlinear functions of the input signal. The proposed device may pave the way for wave-based reconfigurable nonlinear signal processing that can be combined with linear networks for full-fledged wave-based analog computing.
A comparison of phase change materials in reconfigurable silicon photonic directional couplers
利用相变材料独特的光学性质可以开发出高效的可重构光子器件。在这里，我们基于以下因素设计、建模和比较可编程1X2光耦合器的性能：Ge $_2$ Sb $_2$ Te $_5$，Ge $_2$ Sb $_2$ Se $_4$ Te $_1$，Sb $_2$ Se $_3$，和Sb $_2$ S $_3$ PCM。一旦被编程，这些设备是无源的，与热光或电光可重构设备相比，这可以减少总能耗。在所研究的所有PCM中，我们的椭圆偏振法折射率测量显示Sb $_2$ S $_3$在电信波长带中具有最低的吸收。此外，基于Sb $_2$ S $_3$的耦合器显示出最佳的整体性能，在非晶态和晶态下具有最低的插入损耗。我们表明，通过生长结晶调谐至少四个不同的耦合比可以可靠地编程到锑$_2$ S $_3$定向耦合器。我们利用这种效应设计了一个动态范围接近32 dB的2位可调Sb $_2$ S $_3$定向耦合器。耦合器的位深度似乎受到结晶随机性的限制。
Reconfigurable and Recyclable Low-Threshold Quasi-BIC Lasers via a Tunable polymer Coating
Key Laboratory of Multiscale Spin Physics (Ministry of Education), Applied Optics Beijing Area Major Laboratory, School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院，多尺度自旋物理教育部重点实验室，应用光学北京地区重大实验室）
Highly efficient optical add-drop filter with an angle-polished fiber coupler
微泡回音壁谐振器由于其低限制损耗和中空纤芯而在光纤通信中显示出巨大的前景，这允许容易的基于应力的可调谐性。通常情况下，锥形耦合微泡的透射光谱包含紧密间隔的模式，由于相对较大的半径和扁的微泡的几何形状。在这封信中，我们开发了一个光分插滤波器使用的微泡耦合到光纤锥和角抛光光纤波导。由于角度抛光光纤的抛光表面具有额外的角度自由度，因此可以在光学微腔中区别性地激发某些径向阶模，降低高模密度，提高分插选择性。我们的鲁棒可调谐分插滤波器的分插效率为85.9%，品质因数为2 x 10^7，对应的线宽为9.68 MHz。作为概念证明，使用内部空气静压以7.3 +/-0.2GHz/bar的速率调谐分出频率，而对分插滤波器性能没有减小的影响。
Reconfigurable all-optical inference via tunable second-harmonic generation and spin-orbit coupling cascade
Guangdong-HongKong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, School of Physics and Optoelectronic Engineering, Foshan University（佛山大学物理与光电工程学院）；Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Department of Optoelectronic Engineering, Jinan University（暨南大学光电工程系）
Electrically reconfigurable dipolar polaritons with highly tunable nonlinearity in a homobilayer microcavity
Tsinghua University（清华大学）；University of Washington（华盛顿大学）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）；National Institute for Materials Science（国立材料研究所）；Nanyang Technological University（南洋理工大学）；Frontier Science Center for Quantum Information（量子信息前沿科学中心）
