Portable atomic clocks with reduced cost, size, weight, and power (CSWaP) are in great demand for a number of DoD systems requiring precise timing in global positioning system-denied environments. Leveraging our substantial capability and facility for developing compact and highly stable laser sources and extensive experience in developing integrated photonic systems, NP Photonics, in collaboration with the University of Arizona, proposes to develop and commercialize a compact and portable atomic clock based on a 2-photon transition in atomic Rb. The proposed atomic clock will utilize a single fiber laser frequency comb and simple temperature stabilized vapor cell, providing significantly reduced CSWaP and improved short and long term fractional frequency instability.