[9a-PA5-1~3] 4.2 Photonics Devices, Photonic Integrated Circuit and Silicon Photonics

English Presentation

[9a-PA5-2] Exceptional Point Chirality Induced Enhancement and Suppression of Quantum Excess Noise

〇(D)Basabdatta Pati¹, Snehashis Sadhukhan^1,2, V. Narayanan¹, Somnath Ghosh² (1.IIT Jodhpur, 2.Mahindra Univ.)

Keywords:

Exceptional Point,Waveguide,Petermann factor

Exceptional points (EPs), non-Hermitian degeneracies where eigenvalues and eigenvectors simultaneously coalesce, have emerged as pivotal phenomena in photonics, enabling asymmetric mode conversion, enhanced sensing, and nonreciprocal light manipulation. However, operation near EPs introduces excess quantum noise due to modal non-orthogonality, quantified by the Petermann factor (K). Here, we investigate the chirality-dependent evolution of the Petermann excess-noise factor during dynamical encirclement of a second-order EP in a non-Hermitian planar waveguide. Clockwise and counterclockwise encirclements reveal distinctly opposite trends of noise enhancement and suppression, demonstrating a clear chirality-dependent noise response. This asymmetry originates from the underlying non-Hermitian topology and chiral state dynamics governing the system. Our results establish a direct link between EP topology, encirclement chirality, and quantum noise behavior, offering new physical insight into non-Hermitian photonic systems. These findings open a promising route toward the design of low-noise, high-sensitivity non-Hermitian photonic devices and sensors that harness topological state evolution for practical applications.