JP2010245805A - Buffer gas mixing ratio setting method, frequency adjusting method of atomic oscillator, and atomic oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frequency adjusting method of an atomic oscillator with which a center frequency of the atomic oscillator can be precisely adjusted by uniquely determining the temperature of a gas cell. <P>SOLUTION: An atomic oscillator includes: a light source 1 comprising a semiconductor laser; a gas cell 2 in which buffer gases and alkali metal atoms in a predetermined mixing ratio are sealed; a heater 8 for heating the gas cell 2 to a predetermined temperature; a temperature setting circuit 10 for setting a temperature of the heater 8 so as to be a desired frequency; a temperature sensor 7 for detecting the temperature of the heater 8; a temperature control circuit 9 for maintaining the heater 8 at the temperature set by the temperature setting circuit 10; a photo detection circuit 3 for detecting transmitted light of the gas cell 2; a control circuit 4 for performing synchronization control on the basis of an EIT signal detected by the photo detection circuit 3; a voltage controlled crystal oscillator 5 in which the output frequency is controlled in accordance with a control signal from the control circuit 4; and a microwave generating circuit 6 for multiplying an output signal from the voltage controlled crystal oscillator 6 to generate a microwave. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a buffer gas mixture ratio setting method, an atomic oscillator frequency adjustment method, and an atomic oscillator, and more particularly to a technique for stably adjusting an output frequency of an atomic oscillator within a minute range.

The atomic oscillator obtains a reference frequency by irradiating a gas cell (a gas cell enclosing an alkali metal atom) with excitation light and observing the transmitted light. That is, when a microwave is irradiated to the double resonance type gas cell and the frequency of the microwave is swept, the transmitted light is absorbed by the gas cell and becomes small when the frequency passes a certain value. That is, when this state is plotted with the frequency of the microwave as the horizontal axis, a profile in which the amount of transmitted light changes in an impulse manner at a certain frequency is obtained. However, the impulse-like peak has a wide spectral width of the impulse-like peak due to the Doppler effect because the gas of alkali metal atoms performs thermal motion. Therefore, a buffer gas (He, Ne, Ar, etc.) is sealed in the gas cell to reduce the Doppler effect so that the spectrum width does not widen. However, it is known that the peak frequency of this profile shifts depending on the temperature characteristics of the buffer gas sealed in the gas cell. In order to avoid this phenomenon, two kinds of buffer gases that cancel each other's temperature characteristics are determined in advance. The method of mixing with the mixing ratio of is taken. By this method, the spectral width is prevented from widening, and the center frequency is stabilized by filling the buffer gas with a mixing ratio that cancels the temperature characteristics. Further, in order to adjust the center frequency, it is necessary to add a frequency adjusting mechanism separately.
As a frequency adjustment mechanism of this atomic oscillator, a digital synthesizer (
There is a method using DDS). Further, as a classical method, as disclosed in Patent Document 1, a technique of changing the intensity of a magnetic field generated by a coil arranged so as to surround a gas cell has been taken.

JP 2002-271197 A Japanese Utility Model Publication No. 4-5729

However, the prior art disclosed in Patent Document 1 not only complicates the circuit but also requires expensive parts such as an integrated circuit. Further, in the conventional technique disclosed in Patent Document 2, the intensity of the magnetic field changes by 1e-8 just by changing the current flowing through the coil by 1 mA, so that it is difficult to adjust the frequency in a minute range. However, there is a problem that a constant current circuit for changing the magnetic field current stably is necessary.
The present invention has been made in view of such problems, and in order to effectively use the temperature characteristics of the buffer gas sealed in the gas cell, the temperature coefficients of the two types of buffer gas in the gas cell to be used are experimentally obtained. The temperature of the gas cell is determined by calculating the mixing ratio of the two types of buffer gas from the temperature coefficient to be obtained as an atomic oscillator and providing the atomic oscillator with a gas cell in which the buffer gas and the alkali metal atom of the calculated mixing ratio are enclosed. Thus, an object of the present invention is to provide a method for adjusting the frequency of an atomic oscillator that can unambiguously adjust the center frequency of the atomic oscillator.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] In an atomic oscillator that controls an oscillation frequency by utilizing light absorption characteristics by a double resonance method using resonance light and a microwave, or a CPT method using a quantum interference effect by two types of resonance light A gas cell buffer gas mixture ratio setting method, wherein the frequency temperature coefficient for the resonance frequency of the buffer gas A having a positive temperature coefficient is Xa, and the frequency temperature coefficient for the resonance frequency of the buffer gas B having a negative temperature coefficient is Xb, When the frequency temperature coefficient of the resonance frequency desired when the buffer gas A and the buffer gas B are mixed with an alkali metal atom is Z, the mixing ratio A ′ of the buffer gas A is A ′ = (Xb−Z )
/ (Xb−Xa), and the mixing ratio B ′ of the buffer gas B is B ′ = (Z−Xa)
/ (Xb−Xa), and the frequency temperature coefficient Z is within the temperature coefficient range of the mixed buffer gas of the buffer gas A and the buffer gas B excluding zero.

When the mixing ratio of the buffer gases A and B is calculated and obtained so as to have the frequency temperature coefficient Z, the temperature characteristic of the mixed buffer gas is a characteristic that uniquely determines the frequency by the temperature of the gas cell. Therefore, the frequency temperature coefficient Xa with respect to the resonance frequency of the buffer gas A having a positive temperature coefficient and the frequency temperature coefficient Xb with respect to the resonance frequency of the buffer gas B having a negative temperature coefficient are experimentally obtained, and the frequency temperature of the required resonance frequency is obtained. When the coefficient is Z, the mixing ratios A ′ and B ′ are A ′ = (Xb−Z) / (Xb−Xa) and B ′ = (Z−X).
a) / (Xb−Xa). However, the frequency temperature coefficient Z is within the temperature coefficient range of the mixed buffer gas of the buffer gas A and the buffer gas B excluding zero.
Thus, if the frequency temperature coefficients Xa and Xb are obtained in advance by experiments, a desired mixing ratio can be obtained by simple calculation.

Application Example 2 The alkali metal atom is any one of cesium or rubidium, and the buffer gas A is any one of nitrogen (N 2), helium (He), and neon (Ne), and the buffer The gas B is any one of argon (Ar) and krypton (Kr).

An alkali metal atom is a general term for the simple elements of six elements of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Cesium or rubidium is often used. The buffer gas A having a positive temperature coefficient enclosed in the gas cell together with cesium or rubidium is nitrogen (N2), helium (He), neon (Ne), and the buffer gas B having a negative temperature coefficient is argon. (Ar) and krypton (Kr) are most suitable. Thereby, the range of a wide temperature coefficient can be covered with the combination of buffer gas.

[Application Example 3] An atomic oscillator that controls the oscillation frequency using light absorption characteristics by a double resonance method using resonance light and microwaves, or a CPT method using a quantum interference effect by two types of resonance light. A method for adjusting the frequency, comprising preparing a gas cell A in which a buffer gas A having a positive temperature coefficient and an alkali metal atom are enclosed, and a buffer gas B having a negative temperature coefficient and the alkali metal atom being enclosed. A procedure for preparing a gas cell B; a procedure for obtaining a frequency temperature characteristic of the gas cell A; a procedure for obtaining a frequency temperature characteristic of the gas cell B;
The procedure for calculating the frequency temperature coefficient Xa of the gas cell A, the procedure for calculating the frequency temperature coefficient Xb of the gas cell B, the mixing ratio A ′ of the buffer gas A, and the mixing ratio B ′ of the buffer gas B are calculated. A step of sealing the buffer gas A and the buffer gas B mixed based on the mixing ratio A ′ and the mixing ratio B ′ and the alkali metal atom in the gas cell, changing the set temperature of the gas cell, And a procedure for adjusting the frequency of the oscillator to a desired frequency.

The present invention provides a procedure for adjusting the frequency of an atomic oscillator. First, as a preparation for acquiring the frequency temperature characteristics of the buffer gases A and B, a gas cell A in which the buffer gas A and alkali metal atoms are enclosed is prepared. Similarly, a gas cell B in which a buffer gas B and alkali metal atoms are enclosed is prepared. Next, frequency temperature data when the gas cell A is set in the atomic oscillator and the set temperature is changed by the heating means of the gas cell A is acquired. Similarly,
The frequency temperature data when the gas cell B is set in the atomic oscillator and the set temperature is changed by the heating means of the gas cell B is acquired. From this frequency temperature data, frequency temperature coefficients Xa, Xb
(Slope of characteristic line) is obtained. Next, when the frequency temperature coefficient of the required resonance frequency is Z, the mixing ratio A ′ of the buffer gas A is obtained as A ′ = (Xb−Z) / (Xb−Xa),
The mixing ratio B ′ of the buffer gas B is determined as B ′ = (Z−Xa) / (Xb−Xa). Next, the buffer gas and the alkali metal atom having the obtained mixing ratio are sealed in the gas cell, the set temperature of the gas cell is changed, and the frequency of the atomic oscillator is adjusted to a desired frequency. Thereby, if the temperature coefficients of the buffer gases A and B are obtained in advance by experiments, the frequency of the atomic oscillator can be uniquely adjusted by changing the set temperature of the gas cell.

Application Example 4 An atomic oscillator that controls the oscillation frequency using light absorption characteristics by a double resonance method using resonant light and microwaves, or a CPT method using a quantum interference effect by two types of resonant light. A gas cell enclosing a buffer gas and an alkali metal atom mixed by the buffer gas mixing ratio setting method described in Application Example 1 or 2, a heating unit for heating the gas cell to a predetermined temperature, and a desired frequency. The temperature setting means for setting the temperature of the heating means and the temperature control means for holding the heating means at the temperature set by the temperature setting means are provided.

The atomic oscillator of the present invention can be applied to an atomic oscillator by a double resonance method or a CPT method. The most characteristic point is the gas cell in which the buffer gas mixed by the buffer gas mixing ratio setting method of the present invention and the alkali metal atom are enclosed. In other words, the buffer gas sealed in the conventional gas cell is set so that the temperature characteristic becomes zero in order to cancel the temperature characteristic of the buffer gas. The temperature characteristics are set to And a temperature setting means for setting the temperature of the heating means,
The frequency of the atomic oscillator is uniquely set from the temperature of the gas cell. Thereby, the center frequency of the atomic oscillator can be uniquely adjusted minutely by determining the temperature of the gas cell.

It is a block diagram which shows the structure of the atomic oscillator by the double resonance system which concerns on embodiment of this invention. It is a figure which shows an example of the temperature characteristic of He, Ne, N2, Ar, and Kr when enclosed with a Rb gas cell and a Cs gas cell. It is a figure which shows the frequency temperature characteristic when the mixing ratio of nitrogen (N2) and argon (Ar) is 42:58 as an example. It is a flowchart explaining the procedure which measures the temperature coefficient of buffer gas. It is the figure which modeled the gas cell which sealed Rb gas in buffer gas A and B, respectively. It is a figure which shows the temperature characteristic of the gas cell A and the gas cell B. FIG.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a block diagram showing a configuration of an atomic oscillator using a double resonance method according to an embodiment of the present invention. This atomic oscillator 50 heats the gas cell 2 to a predetermined temperature, a light source 1 constituted by a semiconductor laser, a gas cell 2 in which a buffer gas and an alkali metal atom mixed by a buffer gas mixture ratio setting method described later are encapsulated. Temperature setting of the heater (heating means) 8, a temperature setting circuit (temperature setting means) 10 for setting the temperature of the heater 8 so as to obtain a desired frequency, a temperature sensor 7 for detecting the temperature of the heater 8, and the temperature setting of the heater 8 Based on the temperature control circuit (temperature control means) 9 that holds the temperature set by the circuit 10, the light detection circuit 3 that detects the transmitted light of the gas cell 2, and the EIT signal detected by the light detection circuit 3 A control circuit 4 for controlling the output frequency, a voltage controlled crystal oscillator 5 whose output frequency is controlled in accordance with a control signal from the control circuit 4, and a voltage controlled crystal oscillation 5 of the output signal by multiplying configured to include a microwave generator 6 for generating microwaves, a.

The atomic oscillator 50 obtains a reference frequency by irradiating the gas cell 2 with excitation light and observing the transmitted light. The gas cell 2 is irradiated with microwaves from the microwave generation circuit 6,
When the frequency of this microwave is swept and the frequency passes a certain value, the transmitted light is absorbed by the gas cell 2 and the transmitted light becomes smaller. That is, when this state is plotted on the horizontal axis with the frequency of the microwave, a profile having a peak at which the transmitted light amount changes in an impulse manner at a certain frequency is obtained. By the way, it is known that the frequency of the peak of this profile is shifted by the buffer gas (He, Ne, Ar, etc.) sealed together with the alkali metal atoms sealed in the gas cell 2. Here, the reason why the buffer gas is sealed in the gas cell 2 is that, when the buffer gas is not sealed, the impulse peak described above is caused by the Doppler effect because the alkali metal atom gas performs thermal motion, and the spectral width of the impulse peak. Will become wider. Since the atomic oscillator is based on the frequency at the tip of its peak, widening will reduce the performance as a frequency reference. Therefore, a buffer gas is sealed in the gas cell 2 to reduce the Doppler effect so that the spectrum width does not widen. (A common method for double resonance type atomic oscillators)
.

However, when a buffer gas is sealed in the gas cell 2, it has a temperature characteristic (Hz / ° C.) that the frequency at which the aforementioned peak appears changes with respect to the temperature of the gas cell 2. By the way, the value of this temperature characteristic varies depending on the type of buffer gas. For example, FIG.
The values as shown in (Reference Electrical Engineering Society Technical Report (II) No. 15) have been reported.
It should be noted in FIG. 2 that the temperature characteristic value has a positive value and a negative value depending on the type of the buffer gas. Therefore, in order to correct the temperature characteristics due to the buffer gas being sealed and make the temperature coefficient appear to be zero, the gas with a positive coefficient and the gas with a negative coefficient are mixed at an appropriate ratio to bring the temperature coefficient close to zero. be able to. For example, from the values shown in FIG. 2, when a mixed gas of Kr and Ne is sealed in the case of the Rb cell, Kr is about 2.1 times the pressure of Ne (Kr:
When encapsulating with Ne = 2.1: 1.0), the temperature characteristic is close to zero, and a stable frequency characteristic with respect to temperature is obtained.

The atomic oscillator 50 of the present invention can be applied to an atomic oscillator based on a double resonance method or a CPT method. And the most characteristic point is in the gas cell 2 in which the buffer gas and the alkali metal atom mixed by the buffer gas mixing ratio setting method of the present invention are enclosed. In other words, the buffer gas sealed in the conventional gas cell is set so that the temperature characteristic becomes zero in order to cancel the temperature characteristic of the buffer gas. The temperature characteristics are set to And the temperature setting circuit 10 which sets the temperature of the heater 8 is provided, and the frequency of the atomic oscillator 50 is set from the temperature of the gas cell 2. Thereby, the center frequency of the atomic oscillator 50 can be finely adjusted by uniquely determining the temperature of the gas cell 2. Although not shown, a circuit that automatically drives the temperature of the atomic oscillator output 13 to the reference frequency by comparing the frequency of the output 13 with the reference frequency may be configured.

FIG. 3 shows an example in which nitrogen (N2) and argon (Ar) are mixed and the pressure ratio is 42: 5.
FIG. 8 is a diagram showing frequency temperature characteristics when the frequency is changed from 8; Temperature coefficient (Hz / ℃ ・ T on the vertical axis
orr), and the horizontal axis represents the pressure ratio of nitrogen (N2) and argon (Ar). Here, nitrogen (N2
) And argon (Ar) pressure ratio of 42:58 is taken as a reference (= 0%). For example, in order to set the temperature coefficient to zero (symbol 11), the pressure ratio between nitrogen (N2) and argon (Ar) may be set to −3% (N2: Ar = 39: 61). Also, the temperature coefficient is 0.0
It can be seen that in order to obtain 1 (Hz / ° C. · Torr) (reference numeral 12), the pressure ratio of nitrogen (N2) and argon (Ar) should be set to -2% (N2: Ar = 40: 60). . Therefore, if the buffer gas temperature characteristic is set to a mixing ratio having a predetermined temperature coefficient, the frequency can be adjusted by the temperature of the gas cell. That is, a minute temperature coefficient can be easily realized by adjusting the mixing ratio optimally. For example, in the case of an Rb gas cell, the mixing ratio of krypton (Kr) and neon (Ne) is
Assuming that Kr: Ne = 2.0: 1.0, the temperature characteristic of Kr is −2.0 Hz / ° C. and the temperature characteristic of Ne is +4.2 Hz / ° C. from FIG. A gas cell having a temperature coefficient of 2 Hz / ° C. can be realized. Thus, the temperature of the gas cell is very reasonable because it can be achieved simply by changing the resistance of the temperature control circuit 9.

FIG. 4 is a flowchart for explaining the procedure for measuring the temperature coefficient of the buffer gas. First, a gas cell in which one of buffer gas A and buffer gas B and an alkali metal atom are enclosed is prepared (gas cells 20 and 21 in FIG. 5) (S1). At this time, the buffer gas A has a positive temperature coefficient, and the buffer gas B has a negative temperature coefficient. Next, as shown in FIG.
Output frequency data of the atomic oscillator when the set temperature is changed for each of the gas cells A and B is acquired (S2). For example, as shown in FIG. 6, when the atomic oscillator output frequency when the set temperature of the gas cell A is changed from t1 to t2 changes by Δf, a straight line 22 connecting the two points a and b is the characteristic of the gas cell A. Similarly, the straight line 23 is the characteristic of the gas cell B. Next, the frequency temperature coefficient of the gas cells A and B is calculated from the straight line of FIG. 6 (S3). For example, assuming that the output frequency has changed by Δf when t2−t1 = 1 ° C., the frequency temperature coefficient Xa of the gas cell A is Δf. Similarly, the frequency temperature coefficient Xb of the gas cell B is calculated. Next, the mixing ratio of the buffer gases A and B is calculated (S4). The calculation method of the mixing ratio is such that the mixing ratio of the buffer gases A and B is A ′ and B ′, and the desired temperature coefficient to be obtained as an atomic oscillator is Z [Hz / ° C. · Tor
r]
Xa × A ′ + Xb × B ′ = Z (1)
A ′ + B ′ = 1 (2)
From the above formulas (1) and (2), the mixing ratios A ′ and B ′ are calculated,
A ′ = (Xb−Z) / (Xb−Xa)
B ′ = (Z−Xa) / (Xb−Xa)
Ask for. Next, the buffer gas A with the mixing ratios A ′ and B ′ obtained from the equations (1) and (2)
, B and alkali metal atoms are sealed in the gas cell 2 (S5). Finally, the gas cell 2 is set to the configuration shown in FIG. 1, and the temperature setting circuit 10 sets the temperature of the gas cell 2 to a predetermined temperature.
Check the output frequency 13 of the atomic oscillator. If the output frequency 13 deviates from the desired frequency, the temperature setting circuit 9 changes the set temperature of the gas cell 2 and adjusts the output frequency 13 of the atomic oscillator 50 to the desired frequency (S6). .

That is, this flowchart provides a procedure for adjusting the frequency of the atomic oscillator 50. First, as a preparation for acquiring the frequency temperature characteristics of the buffer gases A and B, a gas cell A in which the buffer gas A and alkali metal atoms are enclosed is prepared. Similarly, a gas cell B in which a buffer gas B and alkali metal atoms are enclosed is prepared. Next, frequency temperature data when the gas cell A is set in the atomic oscillator and the set temperature is changed by the heater 8 of the gas cell is acquired (22 in FIG. 6). Similarly, frequency temperature data when the gas cell B is set in the atomic oscillator and the set temperature is changed by the heater 8 of the gas cell is acquired (23 in FIG. 6).
Frequency temperature coefficients Xa and Xb (gradient of characteristic line) are obtained from the frequency temperature data. Next, when the frequency temperature coefficient of the required resonance frequency is Z, the mixing ratio A ′ of the buffer gas A
A ′ = (Xb−Z) / (Xb−Xa), and the mixing ratio B ′ of the buffer gas B is B
It calculates | requires as' = (Z-Xa) / (Xb-Xa). Next, buffer gas and alkali metal atoms with the obtained mixing ratio are sealed in the gas cell 2, the set temperature of the gas cell 2 is changed, and the frequency of the atomic oscillator 50 is adjusted to a desired frequency. Thereby, if the temperature coefficients of the buffer gases A and B are obtained in advance by experiments, the frequency of the atomic oscillator 50 can be uniquely adjusted by changing the set temperature of the gas cell 2.

Further, when the mixing ratio of the buffer gases A and B is calculated and obtained so as to have the frequency temperature coefficient Z, the temperature characteristics of the mixed buffer gas are determined by the temperature of the gas cell 2 and the frequency is uniquely determined. Become. Therefore, the frequency temperature coefficient Xa with respect to the resonance frequency of the buffer gas A having a positive temperature coefficient and the frequency temperature coefficient Xb with respect to the resonance frequency of the buffer gas B having a negative temperature coefficient are experimentally obtained, and the frequency temperature of the required resonance frequency is obtained. When the coefficient is Z, the mixing ratios A ′ and B ′ are A ′ = (Xb−Z) / (Xb−Xa) and B ′ =
It can be calculated as (Z-Xa) / (Xb-Xa). However, the frequency temperature coefficient Z is
It is within the temperature coefficient range of the mixed buffer gas of buffer gas A and buffer gas B excluding zero. Thus, if the frequency temperature coefficients Xa and Xb are obtained in advance by experiments, a desired mixing ratio can be obtained by simple calculation.
Alkali metal atoms include lithium (Li), sodium (Na), potassium (K
), Rubidium (Rb), cesium (Cs), and francium (Fr), but is a general term for a single element. In the case of an atomic oscillator, cesium or rubidium is often used. And buffer gas A having a positive temperature coefficient enclosed in a gas cell together with cesium or rubidium
FIG. 2 shows that nitrogen (N2), helium (He), and neon (Ne) are optimal, and argon (Ar) and krypton (Kr) are optimal as the buffer gas B having a negative temperature coefficient. Thereby, the range of a wide temperature coefficient is realizable with the combination of buffer gas.

1 light source, 2 gas cell, 3 light detection circuit, 4 control circuit, 5 voltage controlled crystal oscillator,
6 Microwave generation circuit, 7 Temperature sensor, 8 Heater, 9 Temperature control circuit, 10
Temperature setting circuit, 50 atomic oscillator

Claims (4)

Mixing the buffer gas of the gas cell in the atomic oscillator that controls the oscillation frequency using the optical absorption characteristics by the double resonance method using resonant light and microwaves, or the CPT method using the quantum interference effect of two types of resonant light A ratio setting method,
The frequency temperature coefficient with respect to the resonance frequency of the buffer gas A having a positive temperature coefficient is Xa,
When the frequency temperature coefficient with respect to the resonance frequency of the buffer gas B having a negative temperature coefficient is Xb, and the frequency temperature coefficient of the resonance frequency desired when the buffer gas A and the buffer gas B are mixed with alkali metal atoms is Z. In addition,
The mixing ratio A ′ of the buffer gas A is determined as A ′ = (Xb−Z) / (Xb−Xa), and the mixing ratio B ′ of the buffer gas B is calculated as B ′ = (Z−Xa) / (Xb−Xa). )
The method of setting a buffer gas mixture ratio, wherein the frequency temperature coefficient Z is within a temperature coefficient range of a mixed buffer gas of the buffer gas A and the buffer gas B excluding zero. The alkali metal atom is any one of cesium or rubidium, the buffer gas A is any one of nitrogen, helium, and neon, and the buffer gas B is any one of argon and krypton. The buffer gas mixture ratio setting method according to claim 1. It is a frequency adjustment method for an atomic oscillator that controls the oscillation frequency by utilizing the light absorption characteristics by the double resonance method using resonant light and microwaves, or the CPT method using the quantum interference effect of two types of resonant light. And
A procedure for preparing a gas cell A in which a buffer gas A having a positive temperature coefficient and an alkali metal atom are enclosed; a procedure for preparing a gas cell B in which a buffer gas B having a negative temperature coefficient and the alkali metal atom are enclosed; The procedure for obtaining the frequency temperature characteristic of the gas cell A, the procedure for obtaining the frequency temperature characteristic of the gas cell B, the procedure for calculating the frequency temperature coefficient Xa of the gas cell A, and the frequency temperature coefficient Xb of the gas cell B The procedure for calculating, the procedure for calculating the mixing ratio A ′ of the buffer gas A and the mixing ratio B ′ of the buffer gas B, and the buffer gas A mixed based on the mixing ratio A ′ and the mixing ratio B ′ And the procedure of enclosing the buffer gas B and the alkali metal atom in the gas cell, changing the set temperature of the gas cell, and the frequency of the atomic transmitter Frequency adjusting method of an atomic oscillator, characterized in that and a procedure for adjusting the desired frequency. An atomic oscillator that controls an oscillation frequency by using a light absorption characteristic by a double resonance method using resonance light and a microwave, or a CPT method using a quantum interference effect by two types of resonance light,
A gas cell containing the buffer gas and alkali metal atoms mixed by the buffer gas mixture ratio setting method according to claim 1 or 2, heating means for heating the gas cell to a predetermined temperature, and a desired frequency An atomic oscillator comprising: temperature setting means for setting a temperature of the heating means; and temperature control means for holding the heating means at a temperature set by the temperature setting means.

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