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arXiv · 2505.15591

Fiber-coupled external cavity DFB-laser

David C. Nak·Jasper Riebesehl·Andreas Hemmerich
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Abstract

Narrow-linewidth, compact and robust laser systems are of high interest, especially with prospects for portable quantum metrological applications. We realized an external cavity DFB-laser incorporating an intra-cavity EOM in a fully fiber-coupled manner. Additional active feedback on the EOM, by referencing a high finesse cavity, enabled us to reach low kHz-linewidths. We analyzed the laser spectrum by means of delayed self-heterodyne measurements to reconstruct the power spectral density. This is achieved by utilizing a data-driven power spectrum equalization approach. The presented laser setup is successfully used to create an ultracold gas by laser cooling on a narrow atomic transition of ${}^{40}$Ca at 1978 nm.

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David C. Nak, Jasper Riebesehl, Andreas Hemmerich. 2025-05-21. Fiber-coupled external cavity DFB-laser. https://arxiv.org/abs/2505.15591

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