
540 Laser-based measurements for time and frequency domain applications
FIGURE 7.51 (SEE CO LOR INSERT)
Picture of the
87
Rb D
1
chip-scale atomic clock and level diagram for CPT spectroscopy.
The two optical transitions (D
1
radiation at 795 nm), represented by the arrows, form the
Λ system in the case of σ
−
polarization. These transitions connect the ground sta te le vels
F = 1, m
F
= 0, F = 2, m
F
= 0 (of interest in the implementation of a frequency standard)
to a common level F
′
= 2, m
F
= −1 of the excited state. (Courtesy of [748].)
Most microwave laboratory ion standards are based on laser-c oo led ions in a linear Paul
trap [750]. Recent work has concen ...