Integrated high-quality multi-wavelength quantum light source compatible with ITU Channel Grid

Abstract

Scalable quantum networks require high-quality multi-wavelength light sources to enable simultaneous quantum communication among multiple users 1 . However, realizing such sources with high brightness, low noise, and chip-scale integration remains challenging. We demonstrate a high-quality and multi-wavelength quantum light source based on a periodically poled thin-film lithium niobate (TFLN) microring resonator employing spontaneous parametric down-conversion (SPDC) with a 100-GHz free spectral range (FSR), compatible with International Telecommunication Union (ITU) Channel Grid. In our experiment, twelve pairs of non-degenerate photon pairs are generated, exhibiting a photon-pair generation rate (PGR) of 817 MHz/mW, brightness of 1.86 × 10 9 Hz/mW 2 /GHz, and a coincidence-to-accidental ratio (CAR) of 51,829 ± 2204. The source enables predictable single photons with g (2) (0) = 0.015 ± 0.006 and energy-time entanglement with 99.5% raw visibility. Operating at room temperature, telecom wavelengths, and compatible with network channels, this work represents a crucial step toward realistic scalable, integrated quantum photonic networks in the future.