Patent ID: 8253503

Claim:
An atomic oscillator comprising: a gaseous alkali metal atom; a light source to generate a resonant light for generating an electromagnetically induced transparency phenomenon in the gaseous alkali metal atom; a high frequency generation unit that supplies a high frequency signal to the light source and generates a resonant light pair; a center frequency variable unit that supplies a direct current signal to the light source and varies a center frequency of the resonant light pair; a light detection unit that detects resonant light of the resonant light pair transmitted through the gaseous alkali metal atom and outputs a detection signal corresponding to intensity of the transmitted resonant light of the transmitted resonant light pair; an absorption detection unit that detects a minimum value of the detection signal when the frequency of the resonant light is varied; and a signal processing unit that controls supply or stop of the high frequency signal outputted from the high frequency generation unit, wherein the signal processing unit compares the minimum value detected by the absorption detection unit with the detection signal in a state where output of the high frequency signal is stopped, controls the center frequency variable unit to cause the detection signal to become larger than the minimum value by a specified value, and sets a center frequency of the resonant light pair to be lower than the frequency of the resonant light corresponding to the minimum value.