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arXiv · 2411.06532

Incoherent Measurement of Sub-10 kHz Optical Linewidths

Félix Montjovet-Basset·Jayash Panigrahi·Diana Serrano·Alban Ferrier·Emmanuel Flurin·Patrice Bertet·Alexey Tiranov·Philippe Goldner
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Abstract

Quantum state lifetimes $T_2$, or equivalently homogeneous linewidths $\Gamma_h = 1/\pi T_2$, are a key parameter for understanding decoherence processes in quantum systems and assessing their potential for applications in quantum technologies. The most common tool for measuring narrow optical homogeneous linewidths, i.e. long $T_2$, is the measurement of coherent photon echo emissions, which however gives very weak signal when the number of emitters is small. This strongly hampers the development of nano-materials, such as those based on rare earth ions, for quantum communication and processing. In this work we propose, and demonstrate in an erbium doped crystal, a measurement of photon echoes based on incoherent fluorescence detection and its variance analysis. It gives access to $T_2$ through a much larger signal than direct photon echo detection, and, importantly, without the need for a highly coherent laser. Our results thus open the way to efficiently assess the properties of a broad range of emitters and materials for applications in quantum nano-photonics.

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Félix Montjovet-Basset, Jayash Panigrahi, Diana Serrano, Alban Ferrier, Emmanuel Flurin, Patrice Bertet, Alexey Tiranov, Philippe Goldner. 2024-11-10. Incoherent Measurement of Sub-10 kHz Optical Linewidths. https://doi.org/10.1103/xkp5-v9m8

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