Atomic oscillator

A gas cell type atomic oscillator employing CPT resonance, comprising:

• a first frequency synthesizer for multiplying a reference frequency signal oscillated with a first voltage control oscillator by a first multiplication ratio and synthesizing a first high frequency signal;
• a first semiconductor laser for emitting a first laser light modulated by the first high frequency signal;
• a second frequency synthesizer for multiplying an output signal oscillated with a second voltage control oscillator by a second multiplication ratio and synthesizing a second high frequency signal;
• a second semiconductor laser for emitting a second laser modulated by the second high frequency signal;
• a gas cell being emitted with the first laser light and the second laser light simultaneously, the gas cell enclosing a first alkali-metal atom gas, a second alkali-metal atom gas, and buffer gas;
• and
• a computer for setting the first multiplication ratio in the first frequency synthesizer,
• the computer comprising:
• a frequency ratio calculator for calculating a frequency ratio of the first high frequency signal to the second high frequency signal,
• a buffer gas pressure estimator for estimating gas pressure of the buffer gas based on the calculated frequency ratio,
• a resonance frequency estimator for estimating the resonance frequency of the first alkali-metal atom based on the estimated gas pressure, and
• a multiplication ratio calculator for calculating the first multiplication ratio based on the estimated resonance frequency of the first alkali-metal atom.