Abstract :
The state of development of optically pumped cesium-beam frequency standards is reviewed. The replacement of magnetic methods for atomic state selection and detection by optical (laser) methods provides potential for major reductions in systematic errors as well as a large increase in useable atomic beam flux. These translate to higher accuracy and better stability (both short and long term) or longer operating life if the beam current is reduced. With current technology it appears possible to construct a laboratory primary standard based on the concept. Simple and inexpensive field standards can also benefit from the optical pumping technology, but additional improvements in stabilized laser diodes will be needed.
