In some embodiments of the chip-scale atomic beam clock, the chip-scale atomic beam clock comprises an atom-beam tube configured to contain the collimated atomic beam generated by the atom collimator. In certain embodiments, the atom-beam tube is configured to be perpendicular to the first photon beam at a first atom-photon interaction region, and the atom-beam tube is configured to be perpendicular to the second photon beam at a second atom-photon interaction region.

In some embodiments of the chip-scale atomic beam clock, the atom collimator and the vertical-cavity surface-emitting laser are configured so that the collimated atomic beam height and the laser photon beam height are the same or about the same.

The chip-scale atomic beam clock may further comprise an actuator configured to mitigate mis-alignment between the vertical-cavity surface-emitting laser and the micro-optical bench. An actuator is a device that causes motion by converting energy and signals going into the system. The motion produced by the actuator may be rotary or linear, for example. The actuator may be configured to move the vertical-cavity surface-emitting laser so that it better aligns with the micro-optical bench. Alternatively, the actuator may be configured to move the micro-optical bench so that it is better aligned with the vertical-cavity surface-emitting laser. The actuator may be controlled using a computer.

The chip-scale atomic beam clock may further comprise a micro-electromechanical system (MEMS) mechanical actuator configured to mitigate mis-alignment between the vertical-cavity surface emitting laser and the micro-optical bench. This MEMS mechanical actuator may be realized through the addition of strain to cantilevered stages holding mirrors or the laser, for example.