“…Bright resonances arise when atoms at zero magnetic field are prepared in a superposition of ground state sublevels that is strongly coupled to the excited state. These resonances have a variety of applications, such as in optical magnetometers [9] and optical switches [10], and they have been studied extensively in many systems both theoretically and experimentally (see, for example, [3,5,11,12,13,14,15,16,17,18,19,20,21]). However, accurately modelling the profiles of bright and dark resonances in systems that are unresolved under Doppler broadening remains a challenging enterprise.…”