Lasing on a narrow transition in a cold thermal strontium ensemble

Highly stable laser sources based on narrow atomic transitions provide a promising platform for direct generation of stable and accurate optical frequencies. Here we investigate a simple system operating in the high-temperature regime of cold atoms. The interaction between a thermal ensemble of ^{88}\mathrm{Sr}at mK temperatures and a medium-finesse cavity produces strong collective coupling and facilitates high atomic coherence, which causes...