On-chip loss-modulated photonic topological edge states in anti-PT-symmetric waveguide arrays

Non-Hermiticity has emerged as a promising tool to induce topological phase transitions, allowing for the design of tunable and functional topological devices such as topological lasers and switches on onchip integrated optical platforms. In this work, we experimentally demonstrate loss-modulated photonic topological edge states in anti-parity-time-symmetric waveguide arrays. Loss is introduced via care-fully designed subwavelength grating (SWG) waveguides, allowing for onchip control of topological responses. Our results show that loss not only induces topological phase transition but also enhances topological responses, leading to the increased localization of topological edge states and the anomaly reduced intrinsic loss of the topological edge states. Our work provides a platform based on SWG waveguides for exploring non-Hermiticity-induced photonic topological responses and corresponding applications.