Svenja Knappe
Atomic Microclocks and Magnetometers
Despite their superior frequency stability, atomic frequency references have been excluded from many portable applications due to their high power consumption and often larger size. Since 2002, chip-scale atomic clocks have been developed with targeted size of 1 cm3 and power consumption of 30 mW, while retaining a fractional frequency stability of 10-11 after one hour of integration. The key technologies, principle of operation, and performance of various commercial prototypes will be presented.
Other atomic sensors can be miniaturized by use of similar technologies: Chip-scale atomic magnetometers that can operate in earth magnetic field have been developed reaching magnetic field sensitivities of 5 pT/Hz1/2 with millimeter size active sensor volumes. In a shielded environment, sensitivities around 20 fT/Hz1/2 have been demonstrated. All-optical fiber-coupled versions could allow for operation in dense arrays or environments where conductive elements in the sensor head are undesirable.
