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arXiv · 2507.08971

Temperature-Tunable Entangled Photon Source for Multiplexed Time-Resolved Fluorescence on a Nanophotonic Platform

Ayantika Sengupta·Nathan A. Harper·Emily Y. Hwang·Scott K. Cushing
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Abstract

Compact, scalable, and multiplexed fluorescence lifetime sensors are of great interest for point-of-care diagnostics. However, current solutions either lack broad-range wavelength-tuning capabilities or involve complex optical setups that hinder miniaturization. On-chip entangled photon sources offer a promising alternative for time-resolved spectroscopy with their strong temporal correlations, tunable spectral characteristics, and small footprints. Here, we develop a temperature-tunable, visible quantum light source on thin-film lithium niobate (TFLN) with a continuous tuning range greater than one octave, spanning 564.5~nm to 1.494~$\mu$m using only one waveguide. The tunability is enabled by utilizing type-I phase matching. We measured an on-chip efficiency of $(3.88\pm0.20)\times10^{9}$ pairs/s/mW, comparable to the most efficient type-0 bulk lithium niobate sources. These results show that the TFLN platform is ideal for on-chip integrated photonic and multiplexed lifetime imaging and sensing.

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Ayantika Sengupta, Nathan A. Harper, Emily Y. Hwang, Scott K. Cushing. 2025-07-11. Temperature-Tunable Entangled Photon Source for Multiplexed Time-Resolved Fluorescence on a Nanophotonic Platform. https://arxiv.org/abs/2507.08971

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