Patent ID: 8253497

Claim:
An atomic oscillator using an electromagnetically induced transparency phenomenon produced by irradiating a resonant light pair to an alkali metal atom, comprising: a gaseous alkali metal atom; a light source that generates a plurality of lights having coherency and including a first light and a second light different in frequency and irradiates the lights to the alkali metal atom; a magnetic field generation part that generates a magnetic field to cause Zeeman splitting in each of a first ground level and a second ground level of the alkali metal atom; a light detection part that receives a light passing through the alkali metal atom and generates a detection signal corresponding to an intensity of the received light; a frequency control part that performs frequency control of at least one of the first light and the second light based on the detection signal and causes the first light and the second light to become the resonant light pair which produces the electromagnetically induced transparency phenomenon in the alkali metal atom; and a magnetic field control part that controls, based on the detection signal, an intensity of the magnetic field generated by the magnetic field generation part, wherein the frequency control part switches a frequency of at least one of the first light and the second light at a specified switching timing, and causes the first light and the second light to sequentially become the resonant light pair which causes a transition between the first ground level and the second ground level corresponding to each of a plurality of magnetic quantum numbers among a plurality of the first ground levels and a plurality of the second ground levels generated by the Zeeman splitting, and the magnetic field control part sequentially acquires profile information capable of specifying an energy difference between the first ground level and the second ground level when the first light and the second light become the resonant light pair to cause the transition between the first ground level and the second ground level corresponding to each of the magnetic quantum numbers, and controls the intensity of the magnetic field generated by the magnetic field generation part based on a plurality of pieces of the acquired profile information to cause the intensity of the magnetic field applied to the alkali metal atom to become constant.