A system for enhancing a coupling laser beam to create a larger beam radius thus increasing sensitivity inside the system. The system includes a coupling laser source to emit a coupling laser defining a first power level. The system also includes a resonant optical cavity that is optically aligned with the coupling laser source and the probe laser source. The resonant optical cavity enhances the coupling laser to a second power level that is greater than the first power level inside of the resonant optical cavity. The power increase of the coupling level also increases the sensitivity of the atomic receiver system by increasing the diameter of the coupling laser inside of the resonant optical cavity. The system also includes at least one photodetector positioned outside of and optically aligned with the resonant optical cavity for monitoring a resonance condition of the coupling laser circulating within the resonant optical cavity.