Figure 1: Ultralow-loss silicon nitride photonic chip (5×5 mm²), incorporating dozens of independent narrow-linewidth quantum light source devices.

Figure 2: Schematic of intracavity spontaneous four-wave mixing, where pump light enters the microcavity and generates narrow-linewidth photon pairs through Kerr nonlinearity.

Platform Introduction

Research Contents & Goals

The Integrated Photonic Quantum Information (IPQI) platform develops practical, on-chip quantum information processing systems. We utilize ultralow-loss silicon nitride (Si₃N₄) to transition complex quantum setups from bulky laboratory benches to compact, CMOS-compatible chips. To date, our platform has developed a world-leading telecom-band integrated photon-pair source and realized the first near-visible integrated photon-pair source. These advancements bridge the gap between laboratory-scale photonic quantum research and its practical deployment.

Looking forward, we aim to modularize our quantum light sources for "turnkey" operation, enabling our chips to function reliably on quantum satellites and in diverse field environments. We are also integrating these sources with ultralow-loss passive Si₃N₄ components to facilitate efficient on-chip multiphoton interference and entanglement, advancing the capabilities of on-chip photonic quantum information processing.

Platform Level & Positioning

The IPQI platform holds a preeminent position in integrated quantum optics on both domestic and international stages. We possess in-house fabrication capabilities for high-quality Si₃N₄ photonic chips. Coupled with our extensive expertise in multi-photon manipulation, we maintain a seamless, end-to-end workflow that spans from quantum application requirements to device design, fabrication, and characterization. This vertical integration enables us to precisely tailor device parameters to the stringent demands of advanced quantum state manipulation.

Representative Achievements

1. Ultralow-loss integrated photonics enables bright, narrow-band, photon-pair sources, Ruiyang Chen, Yi-Han Luo, Jinbao Long, Baoqi Shi, Chen Shen, and Junqiu Liu, Physical Review Letters 133, 083803 (2024). This work has been selected as Optics in 2024 by Optica.

2. Arbitrary-phase locking of fiber Mach-Zehnder interferometers, Ruiyang Chen, Yi-Han Luo, Jinbao Long, and Junqiu Liu, Physical Review Applied 22, 054051 (2024).

3. A scalable near-visible integrated photon-pair source for satellite quantum science, Yi-Han Luo, Yuan Chen, Ruiyang Chen, Zeying Zhong, Sicheng Zeng, Baoqi Shi, Sanli Huang, Chen Shen, Hui-Nan Wu, Yuan Cao, and Junqiu Liu, arXiv 2601.13617 (2026).