Light emitters for on-chip SERF atomic magnetometers based on an inverse design method.

On-chip spin-exchange relaxation-free (SERF) atomic magnetometers (AMs) require linearly polarized light as detection light whose wavelength is 795 nm. In this study, we propose and demonstrate an inverse-designed linearly polarized light emitter suitable for 795 nm wavelength light. Due to the fact that the electric field of the TE fundamental mode is almost a beam of linearly polarized light, we verified whether the emission light obtained when only coupling efficiency is taken as the objective function is linearly polarized. Experimental results indicate that it is. Besides, we introduce an objective function with a circularly polarized component considered and get a right-rotated circularly polarized light emitter, which provides a feasible approach for the development of on-chip optical systems for SERF AMs.