Abstract
Chip-scale non-reciprocity is essential for advancing integrated photonics, particularly in realizing photonic circulators and isolators for data communication, signal modulation, and quantum computing. However, achieving a non-reciprocal silicon chip with a small footprint, high isolation ratio, low loss, and active control remains a challenge. Here, a non-reciprocal topological silicon chip based on magneto-optical Indium Antimonide (InSb) integrated valley Hall system is reported. The valley-conserved non-reciprocal modes, realized by breaking both time-reversal and spatial-inversion symmetries, enable ultra-compact and efficient non-reciprocal photonic devices that outperform conventional chips. A maximum isolation ratio of 64.3 dB and a low chip loss of 2.6 dB is experimentally achieved by fine-tuning the non-reciprocal critical coupling points of a topological cavity with a small footprint of 6.4 × 2.5λ(2). An all-optical method is also applied to actively modulate the isolation ratio from 0 to 48 dB. The development of a non-reciprocal topological silicon chip marks a pivotal advancement in communication systems, LiDAR, terahertz technologies, quantum computing, and cryptography.