JP2011199329A - Heating device, gas cell unit and atomic oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device which can be easily manufactured while being made compact in size, and to provide a gas cell unit and an atomic oscillator.SOLUTION: The heating device 22 heats a gas cell 21 in which gas-like alkali metal atoms are enclosed, and has a substrate 221 and heaters 222a, 222b, 222c and 222d which generate heat when supplied with electric current and which are disposed on the substrate 221. In the heating device 22, the substrate 221 is a printed wiring board, and the heaters 222a, 222b, 222c and 222d are resistors mounted to the substrate 221.

Description

  The present invention relates to a heating device, a gas cell unit, and an atomic oscillator.

An atomic oscillator that oscillates based on the energy transition of alkali metal atoms such as rubidium and cesium generally uses a double resonance phenomenon caused by light and microwaves (for example,
Patent Reference 1) and quantum interference effect (CPT: Coherent P) by two types of light having different wavelengths
opulation Trapping) (for example, see Patent Document 2).
In any atomic oscillator, it is necessary to heat the gas cell to a predetermined temperature in order to enclose the alkali metal together with the buffer gas in the gas cell and keep the alkali metal in a gaseous state.

For example, in the atomic oscillator described in Patent Document 3, a film-like heating element made of a transparent electrode material such as ITO is provided on the outer surface of a gas cell in which gaseous metal atoms are sealed, and this heating element is energized. To generate heat. Thereby, a gas cell can be heated and the metal atom in a gas cell can be kept gaseous. Further, by using such a film-like heating element, the structure for heating the gas cell can be reduced.

However, the atomic oscillator described in Patent Document 3 has a problem that it is difficult to control the thickness of the transparent electrode material as described above on the outer surface of the gas cell. For this reason, the thickness of the film-shaped heating element is likely to vary, and as a result, the inside of the gas cell may not be stably heated.
In addition, there is a problem that a wiring must be formed with a bonding wire for a heating element made of a transparent electrode material, which complicates the manufacturing process and deteriorates the mountability.

Japanese Patent Laid-Open No. 10-284772 US Pat. No. 6,806,784 US Patent Application Publication No. 2006/002276

An object of the present invention is to provide a heating device, a gas cell unit, and an atomic oscillator that can be easily manufactured while downsizing.

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]
The heating device of the present invention is a heating device for heating a gas cell in which gaseous alkali metal atoms are enclosed,
A substrate,
And a heating element that is provided on the substrate and generates heat when energized.
Thereby, a small heating device can be realized. Also, such a heating device
It can be manufactured by a relatively simple method of mounting a heating element on a substrate.

[Application Example 2]
In the heating apparatus of the present invention, the substrate is preferably a printed wiring board.
Various electronic components can be easily mounted on the printed wiring board. Moreover, the printed wiring board is easily available and inexpensive.
[Application Example 3]
In the heating device of the present invention, it is preferable that the heating element is a resistor mounted on the substrate.
The resistor generates heat when energized. Therefore, the resistor can be used as a heating element. In addition, the resistor can be easily mounted on the printed wiring board. Resistors are also readily available and inexpensive.

[Application Example 4]
In the heating apparatus of the present invention, the substrate is preferably provided with a coil for generating a magnetic field.
Thereby, by applying a magnetic field to the alkali metal in the gas cell, the gap between different energy states in which the alkali metal is degenerated can be widened to improve the resolution. As a result, the accuracy of the oscillation frequency of the atomic oscillator can be improved. Further, such a coil can be easily provided on the substrate while reducing the size of the heating device.

[Application Example 5]
In the heating device of the present invention, it is preferable that the coil is configured by a wiring pattern provided on the substrate.
Thereby, a coil can be easily provided in a board | substrate, aiming at size reduction of a heating apparatus.

[Application Example 6]
In the heating apparatus of the present invention, the substrate is a multilayer substrate having a plurality of layers,
The coil is preferably composed of a plurality of wiring patterns provided in the substrate.
Thereby, the winding number of a coil can be increased easily.

[Application Example 7]
In the heating apparatus of the present invention, it is preferable that the wiring pattern has a spiral shape.
Thereby, the winding number of a coil can be increased easily.
[Application Example 8]
In the heating apparatus according to the aspect of the invention, it is preferable that the substrate has a window portion having optical transparency to excitation light that excites the alkali metal atom in the gas cell.
Thereby, the vicinity of the part where the light of the gas cell enters or exits can be efficiently heated.

[Application Example 9]
In the heating apparatus of the present invention, it is preferable that the window portion is a through hole formed in the substrate.
Thereby, a window part can be easily formed in a board | substrate.
[Application Example 10]
In the heating apparatus according to the aspect of the invention, it is preferable that a transparent substrate that covers the through hole and has optical transparency with respect to the excitation light is provided on the substrate.
Thereby, the heat of the heating element can be efficiently transmitted to the portion where the light of the gas cell enters or exits through the transparent substrate while allowing the excitation light to enter and exit the gas cell.

[Application Example 11]
In the heating apparatus of the present invention, it is preferable that the substrate is provided with a temperature sensor for detecting the temperature of the substrate, and energization to the heating element is controlled based on a detection result of the temperature sensor.
Thereby, the alkali metal atom in a gas cell can be maintained at desired temperature. Moreover, such a temperature sensor can be easily mounted on a substrate.

[Application Example 12]
The gas cell unit of the present invention comprises the heating device of the present invention,
And a gas cell heated by the heating device and encapsulating gaseous alkali metal atoms.
As a result, a gas cell unit that is small in size and easy to manufacture can be provided.

[Application Example 13]
The atomic oscillator of the present invention includes the heating device of the present invention,
A gas cell heated by the heating device and encapsulating gaseous alkali metal atoms;
A light emitting portion for emitting excitation light for exciting the alkali metal atoms in the gas cell;
And a light detection unit that detects the intensity of the excitation light transmitted through the gas cell.
Thereby, it is possible to provide an atomic oscillator that is small in size and easy to manufacture.

1 is a block diagram showing a schematic configuration of an atomic oscillator according to a first embodiment of the invention. It is a figure for demonstrating the energy state of the alkali metal in the gas cell with which the atomic oscillator shown in FIG. 1 was equipped. 2 is a graph showing a relationship between a frequency difference between two lights from a light emitting unit and a detection intensity of the light detecting unit for the light emitting unit and the light detecting unit provided in the atomic oscillator shown in FIG. 1. It is a perspective view which shows schematic structure of the gas cell unit with which the atomic oscillator shown in FIG. 1 was equipped. It is sectional drawing which shows the gas cell unit shown in FIG. It is a figure which shows the structure by the side of the gas cell of the heating apparatus with which the gas cell unit shown to FIG. It is a figure which shows the structure on the opposite side to the gas cell of the heating apparatus with which the gas cell unit shown to FIG. It is sectional drawing which shows the gas cell unit which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the gas cell unit which concerns on 3rd Embodiment of this invention.

Hereinafter, a heating device, a gas cell unit, and an atomic oscillator of the present invention will be described in detail based on embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a block diagram showing a schematic configuration of an atomic oscillator according to a first embodiment of the present invention, and FIG. 2 is a diagram for explaining an energy state of an alkali metal in a gas cell provided in the atomic oscillator shown in FIG. FIGS. 3A and 3B are graphs showing the relationship between the frequency difference between two lights from the light emitting portion and the detection intensity of the light detecting portion for the light emitting portion and the light detecting portion provided in the atomic oscillator shown in FIG. 4 is a perspective view showing a schematic configuration of the gas cell unit provided in the atomic oscillator shown in FIG. 1, FIG. 5 is a sectional view showing the gas cell unit shown in FIG. 4, and FIG. 6 is shown in FIGS. The figure which shows the structure by the side of the gas cell of the heating apparatus with which the gas cell unit was equipped, FIG. 7 is a figure which shows the structure on the opposite side to the gas cell of the heating apparatus with which the gas cell unit shown to FIG. For convenience of explanation, the illustration of an insulating layer 236 described later is omitted in FIG. 1, and the illustration of an insulating layer 226 described later is omitted in FIG.

(Atomic oscillator)
First, the overall configuration of the atomic oscillator will be briefly described. In the following, the case where the present invention is applied to an atomic oscillator using the quantum interference effect will be described as an example. However, the present invention is not limited to this, and the atomic oscillator using the double resonance effect is described. It is also applicable to.
An atomic oscillator 1 shown in FIG. 1 includes a gas cell unit 2 including a gas cell 21 enclosing a gaseous alkali metal and heating devices 22, 23, a light emitting unit 3, a light detecting unit 4, and a control unit 5.
And have.

The gas cell 21 is filled with gaseous alkali metal such as rubidium, cesium, and sodium. The gas cell unit 2 will be described in detail later.
As shown in FIG. 2, the alkali metal has a three-level energy level, and has three ground states (ground states 1 and 2) having different energy levels and an excited state. Can take. Here, the ground state 1 is a lower energy state than the ground state 2.

When such a gaseous alkali metal is irradiated with two kinds of resonant lights 1 and 2 having different frequencies on the gaseous alkali metal as described above, the frequency ω1 of the resonant light 1 and the frequency ω2 of the resonant light 2 In accordance with the difference (ω1−ω2) in the alkali metal of the resonant lights 1 and 2 (
Light transmittance) changes.
When the difference (ω1−ω2) between the frequency ω1 of the resonant light 1 and the frequency ω2 of the resonant light 2 coincides with the energy difference between the ground state 1 and the ground state 2, the ground states 1 and 2 change to the excited state. Each excitation stops. At this time, both the resonant lights 1 and 2 are transmitted without being absorbed by the alkali metal. Such a phenomenon is called the CPT phenomenon or electromagnetically induced transparency phenomenon (EIT: Electr
omagnetically Induced Transparency).

The light emitting unit 3 emits excitation light that excites alkali metal atoms in the gas cell 21.
More specifically, the light emitting unit 3 includes two types of light having different frequencies (resonant light 1 and resonant light 2).
Is emitted.
The frequency ω1 of the resonant light 1 can excite the alkali metal in the gas cell 21 from the ground state 1 to the excited state.

The frequency ω2 of the resonant light 2 is the ground state 2 described above for the alkali metal in the gas cell 21.
Can be excited to an excited state.
The light detection unit 4 detects the intensities of the resonance lights 1 and 2 transmitted through the gas cell 21.
For example, the above-described light emitting unit 3 fixes the frequency ω1 of the resonant light 1 and the frequency ω2 of the resonant light 2
Is changed, the difference between the frequency ω1 of the resonant light 1 and the frequency ω2 of the resonant light 2 (ω1−ω2).
) Coincides with the frequency ω 0 corresponding to the energy difference between the ground state 1 and the ground state 2, the detection intensity of the light detection unit 4 increases sharply as shown in FIG. Such a steep signal is represented by E
Detect as IT signal. This EIT signal has an eigenvalue determined by the type of alkali metal. Therefore, an oscillator can be configured by using such an EIT signal.

The control unit 5 has a function of controlling the heating devices 22 and 23 and the light emitting unit 3.
Such a control unit 5 is applied to the frequency control circuit 51 that controls the frequencies of the resonant lights 1 and 2 of the light emitting unit 3, the temperature control circuit 52 that controls the temperature of the alkali metal in the gas cell 21, and the gas cell 21. And a magnetic field power supply circuit 53 for controlling the magnetic field to be generated.
The frequency control circuit 51 controls the frequencies of the resonant lights 1 and 2 emitted from the light emitting unit 3 based on the detection result of the light detecting unit 4 described above. More specifically, the frequency control circuit 51 uses the resonance emitted from the light emitting unit 3 so that (ω1-ω2) detected by the above-described light detection unit 4 becomes the above-described frequency ω0 unique to the alkali metal. Control the frequency of light 1 and 2.

Further, the temperature control circuit 52 controls energization to the heat generating portions 222 and 232 of the heating devices 22 and 23 described later based on the detection results of the sensor units 223 and 233 of the heating devices 22 and 23 described later.
Further, the magnetic field power supply circuit 53 controls energization to the coil portions 225 and 235 of the heating devices 22 and 23 described later so that the magnetic field applied to the alkali metal in the gas cell 21 is constant.

(Gas cell unit)
Here, the gas cell unit 2 will be described in detail.
The gas cell unit 2 is provided so as to sandwich the gas cell 21 and the gas cell 21.
It has a pair of heating devices 22 and 23. In the present embodiment, the gas cell unit 2 is shown in FIG.
As shown in FIG. 4, the gas cell 21 is configured to be symmetrical on the incident side and the emission side of the excitation light.

[Gas cell]
The gas cell 21 includes a pair of plate-like portions 211 and 212 and a spacer 2 provided therebetween.
13.
Each of the plate-like portions 211 and 212 has transparency to the excitation light from the light emitting portion 3 described above.

In the present embodiment, the plate-like portions 211 and 212 each have a disk shape. In addition, the shape of the plate-shaped parts 211 and 212 is not limited to what was mentioned above, For example, you may comprise the square plate shape.
Although the material which comprises such plate-shaped parts 211 and 212 will not be specifically limited if it has the transmittance | permeability with respect to excitation light as mentioned above, Glass material, a crystal | crystallization, etc. are mentioned.
The spacer 213 forms the space S between the pair of plate-like portions 211 and 212 described above.

In the present embodiment, the spacer 213 has a cylindrical shape. The diameter of the spacer 213 is equal to the diameter of the plate-like portions 211 and 212 described above. The spacer 213
The shape is not limited to those described above, and for example, the cross section may be a square tube.
The spacer 213 is airtightly joined to the plate-like portions 211 and 212.
Thereby, the space S between the pair of plate-like portions 211 and 212 can be an airtight space.
The material constituting such a spacer 213 is not particularly limited, and may be a metal material, a resin material, or the like, and may be a glass material, crystal, or the like, similar to the plate-like portions 211 and 212.

[Heating device]
The heating devices 22 and 23 are respectively connected to the gas cell 21 described above (more specifically, the gas cell 2
1 (alkaline metal in 1). Thereby, the alkali metal in the gas cell 21 can be maintained in a gaseous state.
In the present embodiment, each of the heating devices 22 and 23 also has a function of applying a magnetic field to the above-described gas cell 21 (more specifically, an alkali metal in the gas cell 21). Thereby, the energy gap between the energy levels of the alkali metal in the gas cell 21 (particularly, the degeneration of the ground state 1 and the ground state 2 described above) can be widened.

In the present embodiment, the heating devices 22 and 23 are provided so as to sandwich the gas cell 21, and are arranged so as to be symmetrical via the gas cell 21.
Such a heating device 22 includes a substrate 221, a heat generating unit 222, a sensor unit 223, a transparent substrate 224, and the other of the substrate 221 provided on one surface (right surface in FIG. 5) of the substrate 221. A coil portion 225 provided on the surface (the left surface in FIG. 5) and an insulating layer 226 covering the coil portion 225 are provided.

Such a heating device 22 is small and can be manufactured by a relatively simple method of mounting a heating element on the substrate 221.
Similarly, the heating device 23 includes a substrate 231 and one surface of the substrate 231 (the left surface in FIG. 5).
Heat generating part 232, sensor part 233 and transparent substrate 234 provided on top, coil part 235 provided on the other surface of substrate 231 (the right side surface in FIG. 5), and insulating layer covering coil part 235 236.
Such a heating device 23 is also small, and can be manufactured by a relatively simple method of mounting a heating element on the substrate 231.

Hereinafter, each part of the heating device 22 will be described in detail. In addition, about the structure of the heating apparatus 23,
Since it is the same as that of the structure of the heating apparatus 22, the description is abbreviate | omitted.
The substrate 221 is configured by combining one or more of resin materials, glass materials, metal materials, and the like.
In particular, the substrate 221 is preferably a printed wiring board. Various electronic components can be easily mounted on the printed wiring board. Moreover, the printed wiring board is easily available and inexpensive.

Such a printed circuit board is not particularly limited and may be either a rigid board or a flexible board. However, a resin material (particularly curable) such as an epoxy resin or a phenol resin is used for a fiber base material such as paper fiber or glass fiber. It is preferable to use a rigid substrate impregnated with a resin. Such a rigid substrate is generally excellent in heat resistance. Therefore, the substrate 221 using such a rigid substrate is excellent in durability. In addition, since the rigid substrate is generally relatively rigid and difficult to deform, unintentional deformation of the heating device 22 is prevented, and as a result, the gas cell 21 can be stably heated.

Such a printed wiring board may be a single layer or a multilayer.
In such a substrate 221, a through hole 2211 that penetrates in the thickness direction is formed at the center.
This through-hole 2211 constitutes a window portion having optical transparency with respect to the excitation light from the light emitting portion 3 described above. Further, the through hole 2211 allows excitation light incident on the gas cell 21 to pass therethrough. Thereby, even when the substrate 221 faces the plate-like portion 211 of the gas cell 21, it is not necessary to configure the substrate 221 with a material having optical transparency to excitation light.
The substrate 221 can be configured using a printed wiring board as described above.

By providing such a window portion (through hole 2211) in the substrate 221, even when the substrate 221 faces the plate-like portion 211 of the gas cell 21, the light emitting portion 3 can irradiate the gas cell 21 with excitation light. . Therefore, the vicinity of the part where the light of the gas cell 21 enters can be efficiently heated.
Note that the substrate 231 of the heating device 23 also has a through-hole 23 that penetrates in the thickness direction at the center thereof.
11, and this through hole 2311 constitutes a window portion having optical transparency with respect to the excitation light from the light emitting portion 3 described above, but this through hole 2311 is emitted from the gas cell 21 (transmitted through the gas cell 21). The transmitted excitation light is transmitted.

In addition, by configuring such a window portion with the through hole 2211, the window portion can be easily formed on the substrate 221.
Further, on the substrate 221 (more specifically, on the surface of the substrate 221 on the gas cell 21 side), the transparent substrate 224 that covers the through-hole 2211 and has light transmittance with respect to the excitation light from the light emitting unit 3.
Is provided. Thereby, it is possible to efficiently transmit the heat of the heat generating part 222 to the portion where the light of the gas cell 21 enters through the transparent substrate 224 while allowing the excitation light to enter the gas cell 21.

The transparent substrate 224 is in close contact with the plate-like portion 211 of the gas cell 21. Thereby, the plate-shaped part 211 of the gas cell 21 can be heated uniformly.
Further, it is preferable that the surface of the transparent substrate 224 on the gas cell 21 side is subjected to a treatment for improving the adhesion with the gas cell 21. Examples of such a treatment include a smoothing treatment, a treatment for applying a liquid excellent in light resistance and heat resistance, such as silicone oil and fluorine oil, and the like.

In the present embodiment, the transparent substrate 224 is quadrangular (more specifically, rectangular) in plan view.
I am doing. In addition, the planar view shape of the transparent substrate 224 is not limited to a quadrangle, and may be a circle, for example.
Further, the transparent substrate 224 is disposed so that the center thereof coincides with the center of the through hole 2211 described above. Thereby, the heat from the heat generating part 222 can be uniformly transmitted to the gas cell 21.

The constituent material of the transparent substrate 224 is not particularly limited as long as it has light transmittance as described above and has heat resistance against heat from the heat generating part 222.
Examples thereof include glass materials and crystal.
The thickness of the transparent substrate 224 varies depending on the thickness of the plate-like portion 211 of the gas cell 21 and the amount of heat generated by the heat-generating portion 222, and is not particularly limited. However, the heat from the heat-generating portion 222 is transferred to the plate-like portion 211 of the gas cell 21. It is preferable that it is thick to some extent so that it can be transmitted uniformly.

A heating unit 222 is provided around the transparent substrate 224.
The heat generating part 222 is provided on the surface of the substrate 221 on the gas cell 21 side. This
The heat of the heat generating part 222 can be efficiently transmitted to the gas cell 21.
Such a heat generating part 222 includes four heat generating elements 222a, 222b, 222c, and 222d.

The four heating elements 222a, 222b, 222c, and 222d are arranged so as to be symmetric with respect to the through hole 2211 of the substrate 221 described above when viewed in plan. Specifically, the four heating elements 222a, 222b, 222c, and 222d are formed on the 4th of the substrate 221 described above.
It is arranged corresponding to one corner. As a result, the heating elements 222a, 222b, 222c
, 222d can be uniformly transferred to the gas cell 21.

In the present embodiment, the heating elements 222a, 222b, 222c, and 222d are resistors (chip components) mounted on the substrate 221 (more specifically, surface mounting), respectively. The resistor generates heat when energized. Therefore, the resistor can be used as a heating element. In addition, the resistor can be easily mounted on the printed wiring board. Resistors are also readily available and inexpensive.

More specifically, as shown in FIG. 6, the heating element 222 a is electrically connected to a pair of terminals 2291 a and 2292 a provided on the substrate 221. Here, the heating element 2
22a and the pair of terminals 2291a and 2292a are joined via a conductive adhesive, solder, or the like.
Similarly, the heating element 222b includes a pair of terminals 2291b and 229 provided on the substrate 221.
2b is electrically connected. Further, the heating element 222c is a 1 provided on the substrate 221.
The pair of terminals 2291c and 2292c are electrically connected. The heating element 222d is
A pair of terminals 2291 d and 2292 d provided on the substrate 221 are electrically connected.

Such terminals 2291a and 2291b are electrically connected to electrodes 227a provided on the substrate 221 through wiring, and the terminals 2292a and 2292b are connected to electrodes 227b provided on the substrate 221 through wiring. Are electrically connected. Thus, the heating elements 222a and 222b can be heated by applying a voltage between the pair of electrodes 227a and 227b, respectively.

Similarly, the terminals 2291c and 2291d are electrically connected to an electrode 227e provided over the substrate 221 through a wiring, and the terminals 2292c and 2292d are connected to an electrode 227f provided over the substrate 221 through the wiring. Are electrically connected. Accordingly, the heating elements 222c and 222d can generate heat by applying a voltage between the pair of electrodes 227e and 227f, respectively.

Such electrodes 227a, 227b, 227e, and 227f are electrically connected to the above-described temperature control circuit 52 through wiring not shown.
Therefore, in the present embodiment, the heating elements 222a and 222b and the heating elements 222c,
222d can be heated by separate energization.
The heating elements 222 a, 222 b, 222 c, and 222 d are not limited to the chip components as described above, and can be configured by, for example, a wiring pattern provided on the substrate 221. In that case, the wiring pattern constituting the heating element is not particularly limited. For example, indium tin oxide (ITO), carbon-based material, barium titanate-based ceramic (Ba
TiO ₃ ), Fe—Cr—Al alloys, Ni—Cr alloys and the like.

Among them, as a constituent material of the wiring pattern (resistance pattern) constituting the heating element, Fe-
A Cr—Al alloy is preferred. Thereby, the wiring pattern which comprises a heat generating body can be made into the electrical resistance required for the heat_generation | fever. Also, the wiring pattern constituting the heating element is Fe-Cr.
When an Al-based alloy is used as the main material, an insulating layer can be formed relatively easily on the outer surface of the wiring pattern simply by heat treatment.
In addition, as a constituent material of the wiring pattern constituting the heating element, ITO, carbon-based material, B
When a material having a self-temperature adjusting function (PTC) such as aTiO ₃ is used, the temperature can be adjusted without using a temperature control device such as a thermostat. Further, the temperature control device can be omitted, and thus the heating device can be reduced in size and power can be saved.

In addition, when a voltage is applied to a material having a self-temperature adjusting function, the temperature of the material itself rises due to Joule heat, but once the temperature reaches a predetermined temperature, the electrical resistance increases rapidly, that is, the current is suppressed. The predetermined temperature can be maintained. Thus, the material having the self-temperature adjusting function is prevented from generating heat above a predetermined temperature, and is excellent in safety.

The amount of heat generated by the heat generating unit 222 is controlled based on the detection result of the sensor unit 223.
The sensor unit 223 includes two temperature sensors 223a and 223b.
The temperature sensor 223a is provided between the heating element 222a and the heating element 222b, and the temperature sensor 223b is provided between the heating element 222c and the heating element 222d.
Such temperature sensors 223a and 223b each have a function of detecting the temperature of the substrate 221. Based on the detection results of the temperature sensors 223a and 223b, energization to the heating elements 222a, 222b, 222c, and 222d is controlled. Thereby, the alkali metal atom in the gas cell 21 can be maintained at a desired temperature.

The temperature sensors 223a and 223b are not particularly limited, and various known temperature sensors such as a thermistor and a thermocouple can be used. Such a temperature sensor is provided on the substrate 2
21 can be easily mounted. Note that the temperature sensor is not necessarily provided on the substrate 221.
Such a terminal 2293a is electrically connected to an electrode 227c provided on the substrate 221 via a wiring, and the terminal 2294a is electrically connected to an electrode 227d provided on the substrate 221 via a wiring. It is connected. Thereby, the temperature detection by the temperature sensor 223a can be performed via the pair of electrodes 227c and 227c.

Similarly, the temperature sensor 223b includes a pair of terminals 2293b and 2293 provided on the substrate 221.
294b is electrically connected.
More specifically, as shown in FIG. 6, the temperature sensor 223 a is electrically connected to a pair of terminals 2293 a and 2294 a provided on the substrate 221. Here, the temperature sensor 223a and the pair of terminals 2293a and 2294a are joined via a conductive adhesive, solder, or the like.

Similarly, the terminal 2293b is electrically connected to the electrode 227g provided over the substrate 221 through a wiring, and the terminal 2294b is electrically connected to the electrode 227h provided over the substrate 221 through the wiring. It is connected. Thereby, the temperature detection by the temperature sensor 223b can be performed via the pair of electrodes 227g and 227h.
Such electrodes 227c, 227d, 227g, and 227h are electrically connected to the temperature control circuit 52 described above via a wiring (not shown).

Then, the temperature control circuit 52 controls the energization amount to the heating elements 222a and 222b described above based on the detection result of the temperature sensor 223a. Further, the temperature control circuit 52 controls the energization amount to the heating elements 222c and 222d described above based on the detection result of the temperature sensor 223b.
In this way, the two heating sensors 222a and 222b are used by using the two temperature sensors 223a and 223b.
, 222c and 222d can be controlled by controlling the energization amount to higher accuracy. Moreover, the temperature variation in the gas cell 21 can be prevented.

On the other hand, as shown in FIG. 7, a through-hole 22 is formed on the surface of the substrate 221 opposite to the gas cell 21.
A coil portion 225 is provided so as to surround 11.
The coil portion 225 is configured by a coil provided on the substrate 221.
Such a coil part 225 generates a magnetic field by energization. Thereby, by applying a magnetic field to the alkali metal in the gas cell 21, a gap between different energy states in which the alkali metal is degenerated can be widened to improve the resolution. As a result, the accuracy of the oscillation frequency of the atomic oscillator 1 can be increased. Also, such a coil portion 225
Can be easily provided on the substrate 221 while reducing the size of the heating device 22.

In addition, the coil constituting the coil unit 225 is configured by a wiring pattern provided on the substrate 221. Thereby, the coil which comprises the coil part 225 can be provided in the board | substrate 221 easily, aiming at size reduction of the heating apparatus 22. FIG.
Further, such a wiring pattern has a spiral shape. Thus, the coil portion 22
5 can be easily increased. As a result, a magnetic field can be efficiently generated from the coil portion 225.

In the present embodiment, the coil unit 225 of the heating device 22 and the coil unit 235 of the heating device 23 are arranged to face each other with the gas cell 21 therebetween. Thereby, in the gas cell unit 2, these coil parts 225 and 235 comprise a Helmholtz type coil.
Moreover, such a coil part 225 also has a function of generating heat when energized. That is,
The coil unit 225 also has a function as a heating element that generates heat when energized.

In addition, one end of the coil constituting the coil portion 225 is electrically connected to the electrode 228a provided on the substrate 221 via a wiring, and the other end of the coil constituting the coil portion 225 is wired. And is electrically connected to an electrode 228b provided on the substrate 221.
Such a pair of electrodes 228a, 228b is electrically connected to the magnetic field power supply circuit 53 described above via a wiring (not shown). Thereby, it can energize to the coil which constitutes coil part 225.

The coil constituting the coil portion 225 is not particularly limited as long as it is conductive and can be patterned on the substrate 221. For example, silver, copper,
Examples thereof include palladium, platinum, gold, and alloys thereof.
A combination of more than one species can be used.
Such a coil portion 225 is covered with an insulating layer 226. Thereby, it can prevent that each part of the coil which comprises the coil part 225 short-circuits unintentionally. Also,
The safety of the heating device 22 can be increased.

The constituent material of the insulating layer 226 is not particularly limited as long as it has insulating properties and can be formed over the substrate 221, but for example, a resin material such as an epoxy resin or a polyimide resin is used. it can.
According to the heating device 22 as described above, it can be easily manufactured while downsizing.
Moreover, according to the gas cell unit 2 provided with such a heating apparatus 22, it becomes size reduction and manufacture becomes easy.
In addition, according to the atomic oscillator 1 including such a gas cell unit 2, it is possible to reduce the size and to manufacture easily.

Second Embodiment
Next, a second embodiment of the present invention will be described.
FIG. 8 is a sectional view showing a gas cell unit according to the second embodiment of the present invention.
The gas cell unit according to the present embodiment is the first described above except that the configuration of the coil is different.
It is the same as that of the gas cell unit concerning embodiment.

In the following description, the gas cell unit of the second embodiment will be described with a focus on differences from the first embodiment, and the description of the same matters will be omitted. In FIG.
The same reference numerals are given to the same configurations as those in the above-described embodiment.
A gas cell unit 2A shown in FIG. 8 includes a gas cell 21 and a pair of heating devices 22A and 23A provided so as to sandwich the gas cell 21.

In the present embodiment, as shown in FIG. 8, the gas cell unit 2A is configured to be symmetrical on the incident side and the emission side of the excitation light with the gas cell 21 as the center. That is, in this embodiment, the heating devices 22A and 23A are provided so as to sandwich the gas cell 21, and the gas cell 2
1 are arranged symmetrically with respect to each other.
Hereinafter, the heating device 22A will be described. In addition, about the structure of 23 A of heating apparatuses, since it is the same as that of 22 A of heating apparatuses, the description is abbreviate | omitted.

The heating device 22A includes a substrate 221A, a heat generating unit 222, a sensor unit 223, a transparent substrate 224, and a coil embedded in the substrate 221A provided on one surface (right surface in FIG. 8) of the substrate 221A. Part 225A.
The board 221A is a multilayer board (multilayer wiring printed board) having a plurality of layers 221a, 221b, 221c, and 221d.

More specifically, in the substrate 221A, the layer 221a, the insulating layer 226a, the layer 221b, the insulating layer 226b, the layer 221c, the insulating layer 226c, the layer 221d, and the insulating layer 226d are stacked in this order.
Each of the layers 221a, 221b, 221c, and 221d is formed by impregnating a fiber base material such as paper fiber or glass fiber with a resin material (particularly a curable resin) such as an epoxy resin or a phenol resin.

In addition, a constituent material of the insulating layers 226a, 226b, 226c, and 226d is not particularly limited, and for example, a resin material such as an epoxy resin or a polyimide resin can be used.
A coil 225a is provided between the layer 221a and the insulating layer 226a.
A coil 225b is provided between 1b and the insulating layer 226b, and the layer 221c and the insulating layer 22 are provided.
6c is provided with a coil 225c, and between the layer 221d and the insulating layer 226d,
A coil 225d is provided.

A through hole 2211A penetrating in the thickness direction is formed in the central portion of the substrate 221A. A transparent substrate 224 is provided so as to close the through hole 2211A.
The coils 225a, 225b, 225c, and 225d are each configured with a wiring pattern provided in the substrate 221A.

Although not shown, the coil 225a and the coil 225b are electrically connected via an electrode that penetrates the layer 221b, and the coil 225b and the coil 225c are electrically connected via an electrode that penetrates the layer 221c. The coil 225c and the coil 225d are electrically connected via an electrode penetrating the layer 221c. As a result, the coils 225a, 225b, 2
25c and 225d can exhibit the same function as the coil wound around the through hole 2211A described above.

Such a coil 225a, 225b, 225c, 225d constitutes a coil portion 225A. Such a coil portion 225A is electrically connected to the magnetic field power supply circuit 53 via a wiring (not shown), and generates a magnetic field when energized. Thereby, the gas cell 2
A magnetic field is applied to the alkali metal in 1.
Thus, the number of turns of the coil of the coil portion 225 can be easily increased by configuring the coil portion 225 with a plurality of wiring patterns provided in the substrate 221A.

In FIG. 8, each of the coils 225a, 225b, 225c, and 225d is formed in a loop shape, but may be wound in a spiral shape like the coil portion 225 of the first embodiment described above.
Even with the gas cell unit 2A according to the second embodiment as described above, the same effects as those of the gas cell unit 2 of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, a third embodiment of the present invention will be described.
FIG. 9 is a cross-sectional view showing a gas cell unit according to the third embodiment of the present invention.
The gas cell unit according to the present embodiment is the first described above except that the configuration of the coil is different.
It is the same as that of the gas cell unit concerning embodiment.

In the following description, the gas cell unit of the third embodiment will be described with a focus on differences from the first embodiment, and description of similar matters will be omitted. In FIG.
The same reference numerals are given to the same configurations as those in the above-described embodiment.
A gas cell unit 2B shown in FIG. 9 includes a gas cell 21, a pair of heating devices 22B and 23B provided so as to sandwich the gas cell 21, and a magnetic field generator 24.

In the present embodiment, as shown in FIG. 9, the gas cell unit 2B is configured to be symmetrical between the excitation light incident side and the emission side with the gas cell 21 as the center. That is, in this embodiment, the heating devices 22B and 23B are provided so as to sandwich the gas cell 21, and the gas cell 2
The magnetic field generator 24 is provided so as to surround the outer peripheral surface of the spacer 213 of the gas cell 21.

Hereinafter, the heating device 22B will be described. In addition, about the structure of the heating apparatus 23B, since it is the same as that of the structure of the heating apparatus 22B, the description is abbreviate | omitted.
The heating device 22B includes a substrate 221B, and a heat generating unit 222, a sensor unit 223, and a transparent substrate 224 provided on one surface (the right surface in FIG. 9) of the substrate 221B.
The substrate 221B is configured by combining one or more of resin materials, glass materials, metal materials, and the like. Further, as the substrate 221B, a substrate obtained by impregnating a fiber base material such as paper fiber or glass fiber with a resin material (particularly a curable resin) such as an epoxy resin or a phenol resin can be used.

A through hole 2211B penetrating in the thickness direction is formed at the center of the substrate 221B. A transparent substrate 224 is provided so as to close the through hole 2211B.
A magnetic field generator 24 is provided between the pair of heating devices 22B and 23B.

The magnetic field generator 24 has a substrate 241.
The substrate 241 includes a plurality of layers 241a, 241b, 241c, 241d, 241e, 2
This is a multilayer board (multilayer wiring printed board) having 41f.
More specifically, the substrate 241 includes a layer 241a, an insulating layer 243a, a layer 241b, and an insulating layer 2.
43b, layer 241c, insulating layer 243c, layer 241d, insulating layer 243d, layer 241e, insulating layer 243e, layer 241f, and insulating layer 243f are stacked in this order.

Each of the layers 241a, 241b, 241c, 241d, 241e, and 241f is made of, for example, a fiber base material such as paper fiber or glass fiber and a resin material (such as epoxy resin or phenol resin).
In particular, it is impregnated with a curable resin).
In addition, the constituent materials of the insulating layers 243a, 243b, 243c, 243d, 243e, and 243f are not particularly limited. For example, a resin material such as an epoxy resin or a polyimide resin can be used.

A coil 242a is provided between the layer 241a and the insulating layer 243a.
A coil 242b is provided between 1b and the insulating layer 243b, and the layer 241c and the insulating layer 24 are provided.
3c is provided with a coil 242c, and between the layer 241d and the insulating layer 243d,
A coil 242d is provided, a coil 242e is provided between the layer 241e and the insulating layer 243e, and a coil 242f is provided between the layer 241f and the insulating layer 243f.
A through hole 2411 penetrating in the thickness direction is formed at the center of the substrate 241. The gas cell 21 is provided in the through hole 2411.

The coils 242a, 242b, 242c, 242d, 242e, 242f are respectively
The wiring pattern is provided in the substrate 241.
Although not shown, the coil 242a and the coil 242b are electrically connected via an electrode that penetrates the layer 241b, and the coil 242b and the coil 242c are electrically connected via an electrode that penetrates the layer 241c. The coil 242c and the coil 242d are electrically connected through an electrode penetrating the layer 241d, and the coil 242d and the coil 242e are connected to the layer 241e.
The coil 242e and the coil 242f are electrically connected to each other through the layer 2
It is electrically connected through an electrode penetrating 41f. Thereby, the coil 242a,
242b, 242c, 242d, 242e, and 242f can exhibit the same function as the coil wound around the through-hole 2411 described above.

The coil part 242 is comprised by such coils 242a, 242b, 242c, 242d, 242e, 242f. In particular, the coil part 242 constitutes a solenoid type coil. Such a coil portion 242 is connected to the magnetic field power supply circuit 53 via a wiring (not shown).
Are electrically connected to each other and generate a magnetic field when energized. Thereby, a magnetic field is applied to the alkali metal in the gas cell 21.

Also by the gas cell unit 2B according to the third embodiment as described above, the same effects as those of the gas cell unit 2 of the first embodiment described above can be exhibited.
As mentioned above, although the heating apparatus of this invention, the gas cell unit, and the atomic oscillator were demonstrated based on embodiment of illustration, this invention is not limited to these.
In the heating device, gas cell unit, and atomic oscillator of the present invention, the configuration of each part can be replaced with any configuration that exhibits the same function, and any configuration can be added.

Moreover, you may make it combine the arbitrary structures of each embodiment mentioned above for the heating apparatus of this invention, a gas cell unit, and an atomic oscillator.
For example, in the above-described embodiment, the case where the two heating devices provided in the gas cell unit have the same configuration has been described, but when the gas cell unit includes two heating devices,
One heating device and the other heating device may have different configurations.

Depending on the size of the gas cell 21, the type of alkali metal used, the amount of heat generated by the heating device, etc., one of the heating devices 22 and 23 may be omitted. Further, the number of heating devices provided in the gas cell unit may be three or more.
Further, in the above-described embodiment, the case where the through hole is provided in the substrate of the heating device and the transparent substrate is provided so as to cover the through hole has been described. However, the present invention is not limited to this, and for example, the transparent substrate is omitted. Also good. In this case, in order to heat the inside of the gas cell 21 uniformly, it is preferable to increase the thickness of the plate portions 211 and 212 of the gas cell 21 by the thickness of the omitted transparent substrate.

Further, in the case where the substrate of the heating device is made of a material having optical transparency to excitation light, it is not necessary to form a through hole in the substrate of the heating device.
In the above-described embodiment, the configuration in which the heating device is disposed so as to face the plate-like portions 211 and 212 of the gas cell 21 has been described. However, depending on the shape and size of the gas cell, the side surface of the gas cell (for example, The heating device may be arranged so as to face the outer peripheral surface of the spacer 213 of the gas cell 21.

Moreover, although embodiment mentioned above demonstrated the case where a heating apparatus was provided with four heat generating bodies, the number of the heat generating bodies of a heating apparatus is not limited to this, 1-3 may be sufficient, 5 There may be more than one. When the gas cell unit 2 includes a plurality of heating devices, the number, size, type, shape, position, etc. of the heating elements included in the heating device may be the same or different.
In the above-described embodiment, the case where two temperature sensors are provided on one substrate of the heating device has been described. However, the number of temperature sensors provided on the substrate of the heating device may be one, 3
There may be more than one.

DESCRIPTION OF SYMBOLS 1 ... Atomic oscillator 2 ... Gas cell unit 2A ... Gas cell unit 2B ... Gas cell unit 3 ... Light emission part 4 ... Light detection part 5 ... Control part 21 ... Gas cell
22 ... Heating device 22A ... Heating device 22B ... Heating device 23 ... Heating device 23
A ... Heating device 23B ... Heating device 24 ... Magnetic field generator 51 ... Frequency control circuit 52 ... Temperature control circuit 53 ... Power supply circuit for magnetic field 211 ... Plate-like portion 212 ... Plate-like portion 213 ... Spacer 221 ... Substrate 221A ... Substrate 221B ... Substrate 22
1a ... layer 221b ... layer 221c ... layer 221d ... layer 222 ... heating part 2
22a ... heating element 222b ... heating element 222c ... heating element 222d ... heating element 2
23 ... Sensor part 223a ... Temperature sensor 223b ... Temperature sensor 224 ... Transparent substrate 225 ... Coil part 225A ... Coil part 225a ... Coil 225b ...
Coil 225c ... Coil 225d ... Coil 226 ... Insulating layer 226a ... Insulating layer 226b ... Insulating layer 226c ... Insulating layer 226d ... Insulating layer 227a ... Electrode 227b ... Electrode 227c ... Electrode 227d ... Electrode 227e Electrode 22
7f ... Electrode 227g ... Electrode 227h ... Electrode 228a ... Electrode 228b ...
Electrode 231 ... Substrate 232 ... Heat generation part 233 ... Sensor part 234 ... Transparent substrate
235 ... Coil part 236 ... Insulating layer 241 ... Substrate 241a ... 241b ...
Layer 241c Layer 241d Layer 241e Layer 241f Layer 242
Coil section 242a ... coil 242b ... coil 242c ... coil 242d ...
Coil 242e Coil 242f Coil 243a Insulation layer 243b
Insulating layer 243c Insulating layer 243d Insulating layer 243e Insulating layer 243f
Insulating layer 2211 Through hole 2211A Through hole 2211B Through hole 229
1a ... terminal 2291b ... terminal 2291c ... terminal 2291d ... terminal 229
2a ... terminal 2292b ... terminal 2292c ... terminal 2292d ... terminal 229
3a ... terminal 2293b ... terminal 2294a ... terminal 2294b ... terminal 231
1 ... Through hole 2411 ... Through hole S ... Space ω0 ... Frequency ω1 ... Frequency ω
2 ... Frequency

Claims (13)

A heating device for heating a gas cell in which gaseous alkali metal atoms are enclosed,
A substrate,
A heating device comprising a heating element provided on the substrate and generating heat when energized.   The heating device according to claim 1, wherein the substrate is a printed wiring board.   The heating device according to claim 2, wherein the heating element is a resistor mounted on the substrate. The heating apparatus according to claim 1, wherein the substrate is provided with a coil that generates a magnetic field. The heating device according to claim 4, wherein the coil is configured by a wiring pattern provided on the substrate. The substrate is a multilayer substrate having a plurality of layers,
The heating device according to claim 5, wherein the coil includes a plurality of wiring patterns provided in the substrate.   The heating device according to claim 5 or 6, wherein the wiring pattern has a spiral shape. The heating device according to any one of claims 1 to 7, wherein the substrate has a window portion having optical transparency to excitation light that excites the alkali metal atoms in the gas cell.   The heating device according to claim 8, wherein the window is a through hole formed in the substrate. The heating apparatus according to claim 9, wherein a transparent substrate that covers the through-hole and has a light transmittance with respect to the excitation light is provided on the substrate. The heating according to any one of claims 1 to 10, wherein a temperature sensor that detects a temperature of the substrate is provided on the substrate, and energization to the heating element is controlled based on a detection result of the temperature sensor. apparatus. A heating device according to any one of claims 1 to 11,
A gas cell unit comprising: a gas cell heated by the heating device and encapsulating gaseous alkali metal atoms. A heating device according to any one of claims 1 to 11,
A gas cell heated by the heating device and encapsulating gaseous alkali metal atoms;
A light emitting portion for emitting excitation light for exciting the alkali metal atoms in the gas cell;
An atomic oscillator comprising: a light detection unit configured to detect an intensity of the excitation light transmitted through the gas cell.

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