Ultra-compact on-chip spectrometer based on thermally tuned topological miniaturized bound states in the continuum cavity
Xinyi Zhou, Xiaoyu Zhang, Yi Zuo, Zihao Chen, Zhiyuan Qian, Zixuan Zhang, Chao Peng, Hongbin Li
Abstract
On-chip spectrometers are key components in many spectral sensing applications owing to their unique advantages in size and in situ detection. In this work, we propose and demonstrate a class of thermally tunable spectrometers by utilizing topological miniaturized bound states in the continuum (mini-BIC) cavities in a photonic crystal (PhC) slab combined with a metal micro-ring heater. We achieve a resolution of 0.19 nm in a spectral range of ∼6 nm, while the device’s footprint is only 42×42 μ m 2 . The mini-BIC spectrometer works in nearly vertical incidence and is compatible with array operation. Our work sheds light on the new possibilities of high-performance on-chip spectrometers for applications ranging from bio-sensing to medicine.