Quantum-Entangled Light Sources and Photonic Quantum Sensing

Bahaa E. A. Saleh

Giuseppe Di Blasio, Federico Simoni, Lorenzo Uboldi +5 more

Quantum light sources, such as entangled photons, offers unique advantages for bio-sensing of light sensitive samples, providing background free and high SNR measurements at ultra-low photon flux. We built a modular set-up based on SPDC entangled photon pairs generation by using a pulsed laser and several single-photon detectors with different time resolution and quantum efficiency to investigate fluorescent complexes. This toolkit paves the way for minimally invasive fluorescence lifetime sensing towards next generation in vivo studies.

Peng Kian Tan, Xi Jie Yeo, Li Jiong Shen +1 more

Classical sensing techniques such as range finding and clock synchronization use timing modulated light sources to provide the timing correlations needed for their implementation. Corresponding quantum schemes utilise spontaneous parametric down converted light sources to provide the timing correlations without the need for timing modulation, although entangled states are too fragile to be fully exploited presently. Here we demonstrate the use of thermal light as an alternative source for timing correlations, via the photon bunching generated from a laser operating below threshold, and showcase its practical viability by successful range finding measurements.

Stefano Pirandola, Bhaskar Roy Bardhan, Tobias Gehring +2 more

Trevor J. Steiner, Joshua E. Castro, Lin Chang +2 more

The AlGaAsOI material platform offers great promise as a source of quantum states of light that can be utilized for enhanced sensing and metrology beyond the standard quantum limit. Here we focus on preliminary results from AlGaAsOI microring resonator sources that demonstrate a 1000-fold improvement in the brightness of entangled photon pairs compared to state-of-the-art chip-scale sources. The source maintains high single photon purity < 99% and time-energy entanglement visibility < 95%.

Panagiotis Vergyris