Atomic oscillator
The present invention provides an atomic oscillator 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 by a second voltage control oscillator with 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.
1. 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.
2. The atomic oscillator of claim 1 , wherein the buffer gas pressure estimator estimating the gas pressure based on the following formula:
P
=
v
1
-
rv
2
r
α
2
-
α
1
wherein P represents the gas pressure; r represents the frequency ratio; ν 1 represents a nominal frequency of the first alkali-metal atom; ν 2 represents a nominal frequency of the second alkali-metal atom; α 1 represents a pressure coefficient of the first alkali-metal atom; and α 2 represents a pressure coefficient of the second alkali-metal atom.
3. The atomic oscillator of claim 1 , the multiplication ratio calculator calculating as the first multiplication ratio, a value derived by dividing 1/2 value of the estimated resonance frequency of the first alkali-metal atom by a targeted frequency of the reference frequency signal.
4. The atomic oscillator of claim 2 , the multiplication ratio calculator calculating as the first multiplication ratio, a value derived by dividing 1/2 value of the estimated resonance frequency of the first alkali-metal atom by a targeted frequency of the reference frequency signal.