Optically excited magnetic sensor module

Abstract

To provide an optical excitation magnetic sensor module capable of uniformly heating a cell in which alkali metal is enclosed.SOLUTION: An optical excitation magnetic sensor module comprises a housing and a cell unit 10 disposed inside the housing. The cell unit 10 includes a cell 11 enclosing alkali metal, a heat conductive member 12 covering the cell 11, and a heater 13 provided in the heat conductive member 12. The cell 11 includes a main body portion 11a having light-passing region LR through which at least one of pump light L1 and probe light L2 passes. The heat conductive member 12 is provided continuously over an entire region of an outer surface 110 of the main body portion 11a excluding the light-passing region LR.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an optically excited magnetic sensor module. [Background technology]

[0002] Patent Document 1 describes an optically excited magnetic sensor module that includes an atomic cell in which an alkali metal is sealed, a holding member that holds the atomic cell, and a heater that is thermally connected to the holding member. According to the optically excited magnetic sensor module described in Patent Document 1, heat from the heater is transferred to the light-transmitting part of the atomic cell via the holding member, thereby heating the alkali metal in the atomic cell.

[0003] In such an optically excited magnetic sensor module, first, the alkali metal sealed in the cell is heated to obtain vaporous alkali metal atoms (alkali metal vapor). The alkali metal vapor is then spin-polarized by optical pumping. When the alkali metal atoms are further affected by a magnet, their spin polarization receives a torque, causing them to rotate and change direction (the angle of rotation). This change in the direction of spin polarization is acquired by irradiating the probe light. In this way, the optically excited magnetic sensor module measures the magnetic field of the measurement target. When measuring a magnetic field using such an alkali metal, it is important to fill the alkali-sealed cell with alkali metal vapor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-72420 Summary of the Invention [Problem to be solved by the invention]

[0005] In the optically excited magnetic sensor module described in Patent Document 1, the holding member is thermally connected to only a portion of the atomic cell, which may result in that portion of the atomic cell being heated before other portions, leading to the risk of uneven heating of the atomic cell. If the atomic cell is heated unevenly, the vapor pressure of the alkali metal in the atomic cell will be dominated by the temperature of a relatively low portion inside the atomic cell, making it impossible to obtain sufficient vapor pressure of the alkali metal for magnetic measurement, which may result in a decrease in the sensitivity and stability of the optically excited magnetic sensor module.

[0006] An object of the present invention is to provide an optically excited magnetic sensor module capable of uniformly heating a cell in which an alkali metal is sealed. [Means for solving the problem]

[0007] The optically excited magnetic sensor module of the present invention comprises a housing and a cell unit arranged within the housing, the cell unit having a cell in which an alkali metal is sealed, a first heat conduction member covering the cell, and a heater provided on the first heat conduction member, the cell including a main body having a light passage area through which at least one of pump light and probe light passes, and the first heat conduction member is provided continuously over the entire outer surface of the main body except for the light passage area.

[0008] In this photoexcited magnetic sensor module, the first thermal conductive member is continuously provided over the entire outer surface of the main body, excluding a light passage region through which at least one of the pump light and the probe light passes. This allows heat generated by the heater to be conducted to the entire cell via the first thermal conductive member, thereby uniformly heating the cell. Therefore, this photoexcited magnetic sensor module makes it possible to uniformly heat the cell in which the alkali metal is sealed.

[0009] In the photo-excited magnetic sensor module of the present invention, the first thermal conductive member may have an opening corresponding to the light passage region, and the cell unit may further have a heat insulating member covering the first thermal conductive member and the heater, the heat insulating member being provided on the entire first thermal conductive member except for the opening. This prevents heat from being released to the outside of the cell unit. As a result, the cells can be heated more efficiently and the temperature rise of the housing can be suppressed.

[0010] The photo-excited magnetic sensor module of the present invention may further include a second thermally conductive member disposed within the housing, and the second thermally conductive member may be provided on the inner surface of the housing. This allows heat generated in the cell unit to be conducted to the entire second thermally conductive member. As a result, for example, when the photo-excited magnetic sensor module is brought close to a measurement object, the photo-excited magnetic sensor module can be prevented from adversely affecting the measurement object due to a localized increase in temperature of the housing.

[0011] The photoexcited magnetic sensor module of the present invention further includes a light-receiving element disposed within the housing and configured to receive the probe light emitted from the cell. The second thermal conductive member may not be provided in a region of the inner surface of the housing corresponding to the light-receiving element. This prevents heat conducted to the second thermal conductive member from being conducted to the light-receiving element, thereby suppressing an increase in the temperature of the light-receiving element. As a result, an increase in dark current in the light-receiving element is suppressed, thereby avoiding a decrease in the signal-to-noise ratio of the signal from the light-receiving element.

[0012] The photoexcited magnetic sensor module of the present invention further includes a substrate on which a light-receiving element is mounted, and the second thermal conductive member does not need to be provided in an area of ​​the inner surface of the housing corresponding to the light-receiving element and the substrate. This prevents heat conducted to the second thermal conductive member from being conducted to the substrate, thereby suppressing increases in the temperature of the substrate and the light-receiving element mounted on the substrate. As a result, thermal damage to the substrate and an increase in dark current in the light-receiving element are suppressed, thereby avoiding a decrease in the signal-to-noise ratio of the signal from the light-receiving element.

[0013] In the optically excited magnetic sensor module of the present invention, the light passing region includes a pump light incident region, a probe light incident region, and a probe light exit region facing the probe light incident region in a second direction perpendicular to a first direction in which the pump light is incident on the pump light incident region, and the width of the pump light incident region in a third direction perpendicular to both the first and second directions may be larger than the widths of the probe light incident region and the probe light exit region in the third direction, thereby making it possible to more reliably excite alkali metal vapor in the optical path of the probe light.

[0014] In the optically excited magnetic sensor module of the present invention, the area of ​​the pump light entrance region may be larger than the areas of the probe light entrance region and exit region, respectively, thereby enabling more reliable excitation of alkali metal vapor in the optical path of the probe light.

[0015] The optically excited magnetic sensor module of the present invention may further include a support member disposed within a housing for positioning the cell unit at a predetermined position within the housing. This allows the cell to be fixed at a predetermined location within the housing with high precision. As a result, it becomes possible to measure the magnetic field at the measurement target with high precision.

[0016] In the optically excited magnetic sensor module of the present invention, the housing may have a wall, and the cell unit may be disposed within the housing so that no space is formed between the wall and the cell unit. This allows, for example, when the outer surface of the wall is brought closer to the measurement object, to reduce the distance between the cell unit and the measurement object. As a result, the magnetic field at the measurement object can be measured with higher sensitivity. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide an optically excited magnetic sensor module capable of uniformly heating a cell in which an alkali metal is sealed. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of an optically excited magnetic sensor module according to an embodiment; [Figure 2] 2 is a cross-sectional view of the optically excited magnetic sensor module taken along line II-II shown in FIG. 1. [Figure 3] FIG. 2 is a left side view of the optically excited magnetic sensor module shown in FIG. [Figure 4] 4 is a cross-sectional view of the optically excited magnetic sensor module taken along line IV-IV shown in FIG. 1. [Figure 5] FIG. 2 is a front view of the optically excited magnetic sensor module shown in FIG. [Figure 6] FIG. 2 is a plan view of the optically excited magnetic sensor module shown in FIG. [Figure 7] FIG. 2 is a bottom view of the optically excited magnetic sensor module shown in FIG. [Figure 8] FIG. 2 is a right side view of the optically excited magnetic sensor module shown in FIG. [Figure 9] FIG. 2 is a perspective view of a cell unit of the optically excited magnetic sensor module shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view of the cell unit taken along line XX shown in FIG. 9. [Figure 11] FIG. 10 is a perspective view of a cell and a heat conduction member of the cell unit shown in FIG. 9. [Figure 12] FIG. 12 is a right side view of the cell and the heat conducting member shown in FIG. [Figure 13] FIG. 12 is a plan view of the cell and the heat conducting member shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and overlapping parts are omitted. [Configuration of optically excited magnetic sensor module]

[0020] As shown in FIGS. 1, 2, 3, and 4, the photoexcited magnetic sensor module 1 includes a housing 2, a first optical system 3, a second optical system 4, a heat conduction member (second heat conduction member) 5, multiple wirings 6, a support 7, and a cell unit 10. The heat conduction member 5, multiple wirings 6, the support 7, and the cell unit 10 are arranged inside the housing 2. In the following description, three mutually orthogonal directions are referred to as the X direction, the Y direction, and the Z direction, respectively. In this embodiment, the Z direction is the first direction, the X direction is the second direction perpendicular to the first direction, and the Y direction is the third direction perpendicular to both the first and second directions. Note that the second wall portion 22 having the inner surface 22b is not shown in FIG. 3.

[0021] The housing 2 has, for example, a rectangular parallelepiped shape. The housing 2 has a first wall portion (wall portion) 21, a plurality of (four in this embodiment) second wall portions 22, and a third wall portion 23. The first wall portion 21 and the third wall portion 23 face each other in the Y direction. Each of the first wall portion 21 and the third wall portion 23 has, for example, a square plate shape. A pair of second wall portions 22 face each other in the Z direction. Another pair of second wall portions 22 face each other in the X direction. Each second wall portion 22 has, for example, a rectangular plate shape with the Y direction as its longitudinal direction. Each second wall portion 22 is connected to the first wall portion 21 and the third wall portion 23, respectively. In this embodiment, the first wall portion 21 and the plurality of second wall portions 22 are integrally formed of, for example, ABS resin. The first wall portion 21 has an inner surface 21a. The multiple second wall portions 22 have inner surfaces 22a, 22b, 22c, and 22d. The inner surface 22a and the inner surface 22c face each other in the Z direction. The inner surface 22b and the inner surface 22d face each other in the X direction. The third wall portion 23 has an opening 23a. The opening 23a has, for example, a rectangular shape.

[0022] The first optical system 3 includes a fiber connector 31, a polarizer 32, a lens 33, a mirror 34, and a quarter-wave plate 35. The first optical system 3 guides the pump light L1 from outside the housing 2 to the cell unit 10. The fiber connector 31 is attached to the support 7 while penetrating the third wall 23. An optical fiber transmitting the pump light L1 is connected to the fiber connector 31. The polarizer 32, the lens 33, the mirror 34, and the quarter-wave plate 35 are attached to the support 7 while being arranged inside the housing 2 along the inner surface 22c of the second wall 22. The polarizer 32, the lens 33, and the mirror 34 are arranged in this order along the Y direction from the fiber connector 31 side. The quarter-wave plate 35 is disposed between the mirror 34 and the cell unit 10. The polarizer 32 linearly polarizes the pump light L1 emitted from the fiber connector 31. The lens 33 collimates the pump light L1 that has passed through the polarizer 32. The quarter-wave plate 35 converts the pump light L1 that has been reflected by the mirror 34 into elliptically polarized light. In the first optical system 3, the pump light L1 that has been output from the fiber connector 31 passes through the polarizer 32 and the lens 33, is reflected by the mirror 34, and then passes through the quarter-wave plate 35 to enter the cell unit 10.

[0023] The second optical system 4 includes a fiber connector 41, a lens 42, a polarizer 43, a pair of mirrors 44a and 44b, a half-wave plate 45, a polarizing beam splitter 46, and a light-receiving unit 47. The second optical system 4 guides the probe light L2 from outside the housing 2 to the cell unit 10 and guides the probe light L2 from the cell unit 10 to the light-receiving unit 47. The fiber connector 41 is attached to the support 7 while penetrating the third wall 23. An optical fiber transmitting the probe light L2 is connected to the fiber connector 41. The lens 42, the polarizer 43, and the mirror 44a are attached to the support 7 while being arranged within the housing 2 along the inner surface 22d of the second wall 22. The lens 42, the polarizer 43, and the mirror 44a are aligned in this order from the fiber connector 41 side along the Y direction. The mirror 44b, the half-wave plate 45, the polarizing beam splitter 46, and the light-receiving unit 47 are attached to the support 7 and arranged within the housing 2 along the inner surface 22b of the second wall 22. The mirror 44b, the half-wave plate 45, the polarizing beam splitter 46, and the light-receiving unit 47 are aligned in this order along the Y direction from the first wall 21 side. The lens 42 collimates the probe light L2 emitted from the fiber connector 41. The polarizer 43 linearly polarizes the probe light L2 that has passed through the lens 42. The half-wave plate 45 generates a phase difference of half a wavelength between the light of a first polarization direction and the light of a second polarization direction perpendicular to the light of the first polarization direction in the probe light L2 that has passed through the cell unit 10. The polarizing beam splitter 46 is a cube-type beam splitter having an optically functional surface 46a. The polarizing beam splitter 46 transmits light of a first polarization direction and reflects light of a second polarization direction.

[0024] The light receiving unit 47 includes a substrate 48, a first light receiving element 49a, and a second light receiving element 49b. The first light receiving element 49a and the second light receiving element 49b are mounted on the substrate 48. The substrate 48 includes a first plate portion 48a, a second plate portion 48b, and a connecting member 48c. The first plate portion 48a extends along the third wall portion 23. The second plate portion 48b extends along the inner surface 22a of the second wall portion 22. A portion of the second plate portion 48b is disposed inside the opening 23a. The first plate portion 48a and the second plate portion 48b are connected to each other via the connecting member 48c. The first light receiving element 49a is disposed on the surface of the first plate portion 48a that faces the polarizing beam splitter 46. The second light receiving element 49b is disposed on the surface of the second plate portion 48b that faces the polarizing beam splitter 46.

[0025] In the second optical system 4, the probe light L2 emitted from the fiber connector 41 passes through the lens 42 and the polarizer 43, is reflected by the mirror 44a, and enters the cell unit 10. The probe light L2 emitted from the cell unit 10 is reflected by the mirror 44b, passes through the half-wave plate 45, and enters the polarizing beam splitter 46. Of the probe light L2 that enters the polarizing beam splitter 46, light with a first polarization direction passes through the optical function surface 46a and enters the first light receiving element 49a, and light with a second polarization direction is reflected by the optical function surface 46a and enters the second light receiving element 49b. In this way, the first light receiving element 49a and the second light receiving element 49b receive the probe light L2 emitted from the cell unit 10 (specifically, the cell 11, which will be described later).

[0026] The heat conduction member 5, the plurality of wirings 6, and the cell unit 10 will be described with reference to Figures 3, 5, 6, 7, and 8. Note that the first wall portion 21 is not shown in Figure 5. The second wall portion 22 having the inner surface 22a is not shown in Figure 6. The second wall portion 22 having the inner surface 22c is not shown in Figure 7. The second wall portion 22 having the inner surface 22d is not shown in Figure 8.

[0027] As shown in FIGS. 3, 5, 6, 7, and 8, the heat conduction member 5 is provided on the inner surface of the housing 2. Specifically, the heat conduction member 5 is continuously provided on the inner surface 21a of the first wall portion 21 and the inner surfaces 22a, 22b, 22c, and 22d of the multiple second wall portions 22. The heat conduction member 5 is in contact with the inner surface 21a of the first wall portion 21 and the inner surfaces 22a, 22b, 22c, and 22d of the multiple second wall portions 22. The heat conduction member 5 is provided on the inner surfaces 22a, 22b, 22c, and 22d of the multiple second wall portions 22, except for the area corresponding to the light-receiving unit 47. In other words, the heat conduction member 5 does not necessarily have to be provided in the area corresponding to the light-receiving unit 47. In this embodiment, the heat conduction member 5 is a sheet-like member formed of a material having higher thermal conductivity than at least the material constituting the housing 2, such as a graphite sheet. The thermal conductive member 5 being continuously provided in a certain region means that the thermal conductive member 5 is provided without gaps in the region and the region is not exposed to the outside. The gaps referred to here are intentionally provided gaps such as notches and openings, and do not include gaps that are unintentionally created due to the processing accuracy or assembly accuracy of the material. The region corresponding to the light-receiving unit 47 (in this embodiment, the region corresponding to the first light-receiving element 49a, the second light-receiving element 49b, and the substrate 48) refers to the region of the inner surface of a second wall portion 22 that overlaps with the light-receiving unit 47 when viewed from the thickness direction of the second wall portion 22.

[0028] The heat conduction member 5 has a first portion 51 and a plurality of second portions 52a, 52b, 52c, and 52d. The first portion 51 is provided on the inner surface 21a of the first wall portion 21. The second portions 52a, 52b, 52c, and 52d are provided on the inner surfaces 22a, 22b, 22c, and 22d of the second wall portions 22, respectively.

[0029] As shown in FIG. 5, the first portion 51 is provided in region R1, which is the entire inner surface 21a. The first portion 51 is in contact with the inner surface 21a. The second portion 52a is provided in a region of the inner surface 22a excluding a region corresponding to the light-receiving unit 47. Specifically, as shown in FIG. 6, the second portion 52a is provided in region R2 excluding a region facing the second plate portion 48b of the substrate 48. The second portion 52b is provided in a region of the inner surface 22b excluding a region corresponding to the light-receiving unit 47. Specifically, as shown in FIG. 3, the second portion 52b is provided in region R3 excluding a region facing the substrate 48, the first light-receiving element 49a, the second light-receiving element 49b, and the half-wave plate 45. Region R3 is a region facing an intermediate portion (part) 61 of each wiring 6 and the cell unit 10. 7, the second portion 52c is provided in a region R4 of the inner surface 22c facing the polarizer 32, the lens 33, and the mirror 34. As shown in FIG. 8, the second portion 52d is provided in a region R5 of the inner surface 22d facing the lens 42 and the polarizer 43.

[0030] Each wire 6 electrically connects the cell unit 10 (specifically, each of the heater 13 and the temperature detection unit 14, which will be described later) to the substrate 48. Each wire 6 is configured by covering a metal wire with an insulating member. As shown in FIG. 3, the middle portion 61 of each wire 6 extends in the Y direction along the inner surface 22b of the second wall portion 22. The middle portion 61 of at least one wire 6 contacts the second portion 52b of the heat conduction member 5. In this embodiment, three wires 6 electrically connect the heater 13 to the substrate 48, and five wires 6 electrically connect the temperature detection unit 14 to the substrate 48.

[0031] The support body 7 has a support member 71, a recess 72, and a presser plate 73. A plurality of components of the first optical system 3 and the second optical system 4 are attached to the support member 71. The recess 72 is defined by the support member 71. As shown in FIGS. 2, 5, and 6, the recess 72 opens to the first wall portion 21 and the inner surface 22a. The presser plate 73 is screwed to the support member 71. The support body 7 positions the cell unit 10 at a predetermined position within the housing 2. Specifically, the recess 72 and the first wall portion 21 position the cell unit 10 in the X and Y directions. The bottom surface of the recess 72 and the presser plate 73 position the cell unit 10 in the Z direction. [Cell unit configuration]

[0032] 9 and 10, the cell unit 10 has, for example, a rectangular parallelepiped shape. The cell unit 10 has a cell 11, a heat conduction member (first heat conduction member) 12, a heater 13, a temperature detection unit 14, and a heat insulating member 15. The cell unit 10 is a portion where pump light L1 enters and exits, and where probe light L2 enters and exits.

[0033] The cell 11 includes a main body 11a and a protruding portion 11b. The cell 11 is formed of a light-transmitting material such as glass. An alkali metal and an inert gas are sealed in the cell 11. The alkali metal sealed in the cell 11 is, for example, potassium, rubidium, or potassium and rubidium. The inert gas sealed in the cell 11 is, for example, nitrogen gas or helium gas. The protruding portion 11b is a tube that communicates with the inside of the main body 11a and is a portion that is sealed off after being used as a passage for introducing the alkali metal and the inert gas.

[0034] The main body 11a has a light passage region LR, which is a portion where the pump light L1 enters and exits and where the probe light L2 enters and exits. That is, the main body 11a has the light passage region LR where at least one of the pump light L1 and the probe light L2 passes through. As shown in FIGS. 11 to 13, the main body 11a has, for example, a rectangular parallelepiped shape. The width W1 of the main body 11a in the X direction is smaller than the width W2 of the main body 11a in the Y direction. The width W3 of the main body 11a in the Z direction is smaller than the width W2 of the main body 11a in the Y direction. The width W1 of the main body 11a in the X direction is larger than the width W3 of the main body 11a in the Z direction. As an example, the widths W1 and W2 are about several mm, and the width W3 is about 10 mm or so. Note that the protrusions 11b are not shown in FIGS. 11, 12, and 13. The light passing region LR also includes an incident region R6 of the probe light L2, an exit region R7 of the probe light L2 facing the incident region R6 of the probe light L2 in the X direction, an incident region R8 of the pump light L1, and an exit region R9 of the pump light L1 facing the incident region R8 of the pump light L1 in the Z direction.

[0035] The main body 11a has an outer surface 110 including a first surface 11c, a second surface 11d, a third surface 11e, a fourth surface 11f, a fifth surface 11g, and a sixth surface 11h. The first surface 11c and the second surface 11d face each other in the Y direction. The third surface 11e and the fourth surface 11f face each other in the X direction. The fifth surface 11g and the sixth surface 11h face each other in the Z direction. A protrusion 11b is located on the second surface 11d.

[0036] An incident region R6 for the probe light L2 is formed on the third surface 11e as a light passage region LR. The probe light L2 enters the cell 11 through the incident region R6. The incident region R6 is located on the first surface 11c side with respect to the center of the third surface 11e in the Y direction. The incident region R6 has, for example, a square shape. A width W4 of one side of the incident region R6 is, for example, about several mm.

[0037] An exit region R7 for the probe light L2 is formed on the fourth surface 11f as a light passing region LR. The probe light L2 exits from the inside of the cell 11 through the exit region R7. The exit region R7 is located on the first surface 11c side of the center of the fourth surface 11f in the Y direction. The exit region R7 faces the entrance region R6 in the X direction. The exit region R7 has, for example, a square shape. A width W4 of one side of the exit region R7 is, for example, about several mm.

[0038] An incident region R8 for the pump light L1 is formed on the fifth surface 11g as a light passage region LR. The pump light L1 enters the interior of the cell 11 through the incident region R8. The incident region R8 is located on the first surface 11c side with respect to the center of the fifth surface 11g in the Y direction. The incident region R8 has, for example, a rectangular shape with the X direction as its longitudinal direction. A width W5 of the incident region R8 in the X direction is larger than a width W6 of the incident region R8 in the Y direction. The widths W5 and W6 are, for example, approximately several mm. The direction in which the pump light L1 enters the incident region R8 for the pump light L1 is the Z direction.

[0039] An emission region R9 for the pump light L1 is formed on the sixth surface 11h as a light passage region LR. The pump light L1 is emitted from inside the cell 11 through the emission region R9. The emission region R9 is located on the first surface 11c side with respect to the center of the sixth surface 11h in the Y direction. The emission region R9 faces the incidence region R8 in the Z direction. The emission region R9 has, for example, a rectangular shape with the X direction as its longitudinal direction. The width W5 of the emission region R9 in the X direction is larger than the width W6 of the emission region R9 in the Y direction. The widths W5 and W6 are, for example, approximately several mm. The pump light L1 emitted from inside the cell 11 through the emission region R9 is incident on a pressure plate 73 (see FIG. 2) and is reflected or absorbed by the pressure plate 73.

[0040] As described above, the width W6 of each of the entrance region R8 and exit region R9 of the pump light L1 in the Y direction is larger than the width W4 of each of the entrance region R6 and exit region R7 of the probe light L2 in the Y direction. The areas of each of the entrance region R8 and exit region R9 of the pump light L1 are larger than the areas of each of the entrance region R6 and exit region R7 of the probe light L2.

[0041] The heat conduction member 12 covers the cell 11. The heat conduction member 12 is continuously provided over the entire region of the outer surface 110 of the main body 11a, excluding the light passage region LR, which includes the entrance region R6 of the probe light L2, the exit region R7 of the probe light L2, the entrance region R8 of the pump light L1, and the exit region R9 of the pump light L1, and is in contact with these regions. That is, the heat conduction member 12 is continuously provided over the entire region of the outer surface 110 of the main body 11a, excluding the light passage region LR. In this embodiment, the heat conduction member 12 is formed, for example, from a material having a higher thermal conductivity than at least the material constituting the cell 11. In this embodiment, the heat conduction member 12 is a sheet-like member formed integrally and attached to the outer surface 110 of the cell 11. In this embodiment, the heat conduction member 12 is, for example, a graphite sheet. As an example, the heat conduction member 12 is formed to have the same shape as the developed view of the outer surface 110 and attached to the outer surface 110. The phrase "thermal conductive member 12 is provided continuously in a certain region" means that thermal conductive member 12 is provided without gaps in a certain region, and the region is not exposed to the outside. The term "gaps" as used here refers to gaps that are intentionally provided by notches, openings, etc., and does not necessarily include gaps that are unintentionally created due to the processing accuracy of materials or the assembly accuracy.

[0042] The heat conduction member 12 includes a first surface 12c, a second surface 12d, a third surface 12e, a fourth surface 12f, a fifth surface 12g, and a sixth surface 12h. The first surface 12c, the second surface 12d, the third surface 12e, the fourth surface 12f, the fifth surface 12g, and the sixth surface 12h are in contact with each other at adjacent surfaces and are thermally connected to each other. The first surface 12c is provided on the first surface 11c and is in contact with the first surface 11c. The second surface 12d is provided on the second surface 11d and is in contact with the second surface 11d. The second surface 12d also covers a portion of the protrusion 11b. The heat conduction member 12 also has an opening 16 corresponding to the light passage region LR. The aperture 16 includes an entrance aperture 16a for the probe light L2, an exit aperture 16b for the probe light L2, an entrance aperture 16c for the pump light L1, and an exit aperture 16d for the pump light L1.

[0043] The third surface 12e is provided over the entire area of ​​the third surface 11e except for the incident area R6 of the probe light L2. An incident opening 16a for the probe light L2 is formed in the third surface 12e as an opening 16. The incident opening 16a for the probe light L2 corresponds to the incident area R6 of the probe light L2. In other words, the incident area R6 is a region defined by the incident opening 16a and is a region exposed to the outside at the incident opening 16a. The third surface 12e is in contact with the third surface 11e.

[0044] The fourth surface 12f is provided over the entire area of ​​the fourth surface 11f excluding the exit region R7 of the probe light L2. An exit opening 16b for the probe light L2 is formed in the fourth surface 12f as an opening 16. The exit opening 16b for the probe light L2 corresponds to the exit region R7 of the probe light L2. In other words, the exit region R7 is an area defined by the exit opening 16b and is an area exposed to the outside at the exit opening 16b. The fourth surface 12f is in contact with the fourth surface 11f.

[0045] The fifth surface 12g is provided over the entire area of ​​the fifth surface 11g excluding the incident area R8 of the pump light L1. An incident opening 16c for the pump light L1 is formed in the fifth surface 12g as an opening 16. The incident opening 16c for the pump light L1 corresponds to the incident area R8 of the pump light L1. In other words, the incident area R8 is an area defined by the incident opening 16c and is an area exposed to the outside from the incident opening 16c. The fifth surface 12g is in contact with the fifth surface 11g.

[0046] The sixth surface 12h is provided over the entire area of ​​the sixth surface 11h excluding the emission region R9 of the pump light L1. An emission opening 16d for the pump light L1 is formed in the sixth surface 12h as an opening 16. The emission opening 16d for the pump light L1 corresponds to the emission region R9 of the pump light L1. In other words, the emission region R9 is an area defined by the emission opening 16d and is an area exposed to the outside at the emission opening 16d. The sixth surface 12h is in contact with the sixth surface 11h.

[0047] As shown in FIG. 10 , the heater 13 is provided on the heat conductive member 12 and is in contact with the heat conductive member 12. In this embodiment, the heater 13 is provided on the sixth surface 12h and is located on the second surface 11d side of the center of the sixth surface 11h in the Y direction. The heater 13 includes a metal wire that generates heat when electricity is applied. As an example, the heater 13 includes a titanium wire and is attached to the sixth surface 12h with polyimide tape. The metal wire of the heater 13 preferably has a high resistance value in order to obtain a high heat output with a low current value. The metal wire of the heater 13 is, for example, a titanium wire with a resistance value of approximately 100 Ω.

[0048] The temperature detection unit 14 is provided on the heat conduction member 12 and is in contact with the heat conduction member 12. In this embodiment, the temperature detection unit 14 is provided on the fifth surface 12g and is in direct contact with the fifth surface 12g. The temperature detection unit 14 is located on the second surface 11d side with respect to the center of the fifth surface 11g in the Y direction. The temperature detection unit 14 is an element for measuring the temperature of the cell 11. The temperature detection unit 14 is, for example, a resistance temperature sensor, and one example is Pt100.

[0049] As shown in FIGS. 9 and 10 , the heat insulating member 15 covers the heat conductive member 12, the heater 13, and the temperature detection unit 14. The heat insulating member 15 is continuously provided over the entire heat conductive member 12 except for the entrance opening 16 a for the probe light L2, the exit opening 16 b for the probe light L2, the entrance opening 16 c for the pump light L1, and the exit opening 16 d for the pump light L1. That is, the heat insulating member 15 is continuously provided over the entire region of the heat conductive member 12 except for the openings 16. In this embodiment, the heat insulating member 15 is each a multi-layer (e.g., three-layer) sheet-like member. Each sheet-like member is formed of a material with higher thermal insulation properties than at least the heat conductive member 12, such as insulating paper made of silica aerogel and synthetic fiber. Note that the heat insulating member 15 being continuously provided in a certain region means that the heat insulating member 15 is provided without gaps in a certain region and is not exposed to the outside. The term "gaps" as used herein refers to gaps that are intentionally provided by notches, openings, etc., and does not necessarily include gaps that are unintentionally created due to the processing accuracy or assembly accuracy of materials.

[0050] 2 and 4, the cell unit 10 configured as described above is in contact with the heat conduction member 5 on the inner surface 21a of the first wall portion 21. In other words, the cell unit 10 is arranged in the housing 2 so that no space is formed between the first wall portion 21 and the cell unit 10. The cell unit 10 is positioned by the support body 7 so that this state is realized and maintained. [Operation of the optically excited magnetic sensor module]

[0051] The optically excited magnetic sensor module 1 is disposed so that the first wall 21 faces the measurement object (i.e., in the cell unit 10, the first surface 11c of the main body 11a of the cell 11 faces the measurement object). In this state, the heater 13 heats the alkali metal sealed inside the cell 11 via the heat conductive member 12, thereby obtaining vaporous alkali metal atoms (alkali metal vapor). In the optically excited magnetic sensor module 1, the first optical system 3 guides the pump light L1 to an entrance region R8 of the cell 11 for the pump light L1. Next, the pump light L1 passes through the inside of the cell 11 from the entrance region R8 to the exit region R9. At this time, the alkali metal vapor inside the cell 11 is spin-polarized by the pump light L1 through optical pumping. Next, the polarizer 43 of the second optical system 4 linearly polarizes the probe light L2 in a first polarization direction. Next, the probe light L2 is guided to the entrance region R6 of the cell 11 for the probe light. Next, the probe light L2 passes through the inside of the cell 11 from the entrance region R6 to the exit region R7. At this time, the probe light L2 passes through the alkali metal vapor inside the cell 11. Here, the spin polarization state of the alkali metal vapor changes due to the influence of the magnetic field of the measurement target. Therefore, the polarization direction of the probe light L2 passing through the alkali metal vapor is changed so that it tilts from the first polarization direction to the second polarization direction. Then, the first light-receiving element 49a detects the light intensity of the first polarization direction component of the probe light L2. The second light-receiving element 49b detects the light intensity of the second polarization direction component of the probe light L2. This detects the difference between the light intensities of the polarization direction components of the probe light L2. Then, the optically excited magnetic sensor module 1 detects the spin polarization state of the alkali metal vapor based on this difference. Finally, the optically excited magnetic sensor module 1 detects the magnetic field of the measurement target from the spin polarization state of the alkali metal vapor. [Action and effect]

[0052] In the photoexcited magnetic sensor module 1, the heat conduction member 12 is continuously provided over the entire outer surface 110 of the main body 11a, excluding the light passage region LR, which includes the pump light L1 entrance region R8, the pump light L1 exit region R9, the probe light L2 entrance region R6, and the probe light L2 exit region R7. Specifically, the heat conduction member 12 is provided without gaps in a certain region, and this region is not exposed to the outside. The heat conduction member 12 has a first surface 12c, a second surface 12d, a third surface 12e, a fourth surface 12f, a fifth surface 12g, and a sixth surface 12h, and adjacent surfaces of these surfaces are in contact with each other and thermally connected to each other. This allows heat generated by the heater 13 to be conducted to the entire outer surface 110 of the cell 11 via each surface of the heat conduction member 12, thereby uniformly heating the cell 11. This provides an photoexcited magnetic sensor module 1 that can uniformly heat the cell 11. Furthermore, in this optically excited magnetic sensor module 1, the cell 11 is uniformly heated, thereby improving the sensitivity and stability of magnetic field measurement. Furthermore, the uniform heating of the cell 11 reduces the amount of energy required to heat the coldest part of the cell 11 to the target temperature. As a result, the power consumption of the optically excited magnetic sensor module 1 is reduced, thereby reducing noise when measuring a magnetic field.

[0053] Here, we will explain the cell unit of the example and the cell unit of the comparative example. The cell unit of the example has a configuration similar to the cell unit 10 described above. The cell unit of the comparative example differs from the cell unit of the example only in that it does not have a configuration equivalent to the thermal conduction member 12. In the cell unit of the comparative example, the maximum temperature value on the outer surface of the cell was up to twice the minimum temperature value. On the other hand, in the cell unit of the example, the maximum temperature value on the outer surface of the cell was less than 1.01 times the minimum temperature value.

[0054] In the photo-excited magnetic sensor module 1, the heat insulating member 15 is continuously provided over the entire heat conducting member 12 except for the entrance opening 16c for the pump light L1, the exit opening 16d for the pump light L1, the entrance opening 16a for the probe light L2, and the exit opening 16b for the probe light L2, which are the openings 16 corresponding to the light passing region LR. This prevents heat from being released to the outside of the cell unit 10. As a result, the cell 11 can be heated more efficiently and the temperature rise of the housing 2 can be suppressed.

[0055] In the optically excited magnetic sensor module 1, the cell unit 10 is arranged in the housing 2 so that no space is formed between the first wall 21 of the housing 2 and the cell unit 10. This reduces the distance between the cell unit 10 and the measurement object, for example, when the outer surface of the first wall 21 is brought closer to the measurement object. As a result, the magnetic field in the measurement object can be measured with higher sensitivity.

[0056] In the photo-excited magnetic sensor module 1, the heat conduction member 5 is continuously provided on the inner surface 21a of the first wall portion 21 and the inner surfaces 22a, 22b, 22c, and 22d of the multiple second wall portions 22. Furthermore, the cell unit 10 is in contact with the heat conduction member 5 at the inner surface 21a of the first wall portion 21. This allows heat generated in the cell unit 10 to be conducted throughout the heat conduction member 5. More specifically, the heat is conducted to the first portion 51 and then to the multiple second portions 52a, 52b, 52c, and 52d. As a result, when the outer surface of the photo-excited magnetic sensor module 1 (particularly the first wall portion 21) is brought close to the measurement object, it is possible to prevent the housing 2 (particularly the first wall portion 21) from becoming locally hot and adversely affecting the measurement object.

[0057] Here, we will explain the photo-excited magnetic sensor module of the Example and the photo-excited magnetic sensor module of the Comparative Example. The photo-excited magnetic sensor module of the Example has a configuration similar to the photo-excited magnetic sensor module 1 described above. The photo-excited magnetic sensor module of the Comparative Example differs from the photo-excited magnetic sensor module of the Example only in that it does not have a configuration equivalent to the heat conduction member 5. In the photo-excited magnetic sensor module of the Comparative Example, the temperature of the first wall portion reached 90°C or higher. On the other hand, in the photo-excited magnetic sensor module of the Example, the temperature of the first wall portion reached approximately 50°C.

[0058] In the photoexcited magnetic sensor module 1, the heat-conducting member 5 is not provided in the region of the inner surface 22a, 22b, 22c, and 22d of the second wall portion 22 corresponding to the light-receiving unit 47 having the first light-receiving element 49a, the second light-receiving element 49b, and the substrate 48, but is provided in regions R1, R2, R3, R4, and R5 excluding the region. This prevents the light-receiving unit 47 from being affected by heat conduction from the heat-conducting member 5, and prevents heat conducted to the heat-conducting member 5 from being conducted to the light-receiving unit 47. This prevents the temperatures of the first light-receiving element 49a, the second light-receiving element 49b, and the substrate 48 from increasing. As a result, an increase in dark current in the first light-receiving element 49a and the second light-receiving element 49b, thermal deformation of the substrate 48, and damage to heat-sensitive components mounted on the substrate 48 are suppressed, thereby preventing a decrease in the signal-to-noise ratio of the signals from the first light-receiving element 49a and the second light-receiving element 49b.

[0059] In the photoexcited magnetic sensor module 1, the intermediate portion 61 of at least one wire 6 is in contact with the second portion 52b of the heat conduction member 5. As a result, when heat generated in the heater 13 and heat conducted to the temperature detection unit 14 is conducted to the intermediate portion 61 of each wire 6, the heat is released to the outside of the housing 2 via the heat conduction member 5. As a result, heat conduction from each wire 6 to the substrate 48 is suppressed, and therefore, an increase in temperature of the first light receiving element 49a and the second light receiving element 49b mounted on the substrate 48 is also suppressed. Therefore, an increase in dark current in the first light receiving element 49a and the second light receiving element 49b, thermal deformation of the substrate 48, and damage to heat-sensitive components mounted on the substrate 48 are suppressed, and a decrease in the signal-to-noise ratio of the signals from the first light receiving element 49a and the second light receiving element 49b can be avoided.

[0060] In the optically excited magnetic sensor module 1, the entrance region R8 of the pump light L1 and the exit region R9 of the pump light L1 face each other in the Z direction, the entrance region R6 of the probe light L2 and the exit region R7 of the probe light L2 face each other in the X direction, and the width W5 of the long side of each of the entrance region R8 and the exit region R9 of the pump light L1 is larger than the width W4 of one side of each of the entrance region R6 and the exit region R7 of the probe light L2. As a result, for example, when viewed from the Z direction, the width W5 of each of the entrance region R8 and the exit region R9 of the pump light is larger than the width of the optical path of the probe light. As a result, alkali metal vapor can be more reliably excited in the optical path of the probe light L2.

[0061] In the optically excited magnetic sensor module 1, the areas of the entrance region R8 and exit region R9 of the pump light L1 are larger than the areas of the entrance region R6 and exit region R7 of the probe light L2, respectively, thereby more reliably exciting the alkali metal vapor in the optical path of the probe light L2.

[0062] In the optically excited magnetic sensor module 1, the support 7 positions the cell unit 10 at a predetermined position within the housing 2. This allows the cell 11 to be fixed with high precision at a predetermined location within the housing 2. As a result, it becomes possible to measure the magnetic field at the measurement target with higher precision.

[0063] In the optically excited magnetic sensor module 1, the entrance region R6 and exit region R7 of the probe light L2 are located on the first surface 11c side with respect to the centers of the third surface 11e and the fourth surface 11f in the Y direction, respectively, and the entrance region R8 and exit region R9 of the pump light L1 are located on the first surface 11c side with respect to the centers of the fifth surface 11g and the sixth surface 11h in the Y direction, respectively. This makes it possible to arrange other components such as the heater 13 and the temperature detection unit 14 in areas of the third surface 11e, the fourth surface 11f, the fifth surface 11g, and the sixth surface 11h closer to the second surface 11d. As a result, when the probe light L2 and the pump light L1 pass through the cell 11, changes in the intensity and polarization state of the probe light L2 and the pump light L1 due to factors other than the spin polarization state of the alkali metal vapor inside the cell 11 are suppressed. Furthermore, since the optical path of the probe light L2 is closer to the first surface 11c in the Y direction, the distance between the optical path of the probe light L2 and the measurement object becomes smaller. As a result, the magnetic field in the measurement object can be measured with higher sensitivity.

[0064] In the photo-excited magnetic sensor module 1, the width W1 of the main body 11a in the X direction is larger than the width W3 of the main body 11a in the Z direction. Here, the longer the width W1 of the main body 11a in the X direction, the longer the distance that the probe light L2 travels through the alkali metal vapor excited by the pump light L1. The longer the distance that the probe light L2 travels through the alkali metal vapor, the more the magnetic field detection sensitivity of the photo-excited magnetic sensor module 1 improves. Therefore, the magnetic field detection sensitivity of the photo-excited magnetic sensor module 1 can be improved. [Variations]

[0065] The present invention is not limited to the above-described embodiment. In the photo-excited magnetic sensor module 1, it is sufficient that the pump light L1 excites the alkali metal vapor inside the cell 11. Therefore, for example, the main body 11a may not include the emission region R9 of the pump light L1. In this case, the heat conduction member 12 is continuously provided over the entire region of the first surface 11c, second surface 11d, third surface 11e, fourth surface 11f, fifth surface 11g, and sixth surface 11h of the main body 11a, excluding the light passage region LR, which is the entrance region R8 of the pump light L1, the entrance region R6 of the probe light L2, and the exit region R7 of the probe light L2. That is, the heat conduction member 12 is continuously provided over the entire region of the outer surface 110 of the main body 11a, excluding the light passage region LR. Specifically, the heat conduction member 12 is provided without gaps in a certain region, and the region is not exposed to the outside. The heat conduction member 12 has a first surface 12c, a second surface 12d, a third surface 12e, a fourth surface 12f, a fifth surface 12g, and a sixth surface 12h, and these surfaces are in contact with each other at adjacent surfaces and thermally connected to each other. This allows heat generated by the heater 13 to be conducted to the entire outer surface 110 of the cell 11 via each surface of the heat conduction member 12, thereby uniformly heating the cell 11. This provides a photoexcited magnetic sensor module 1 capable of uniformly heating the cell 11. Furthermore, in this photoexcited magnetic sensor module 1, the uniform heating of the cell 11 improves the sensitivity and stability of magnetic field measurement. Furthermore, the uniform heating of the cell 11 reduces the amount of energy required to heat the coldest part of the cell 11 to the desired temperature. As a result, power consumption in the photoexcited magnetic sensor module 1 is reduced, thereby reducing noise during magnetic field measurement.

[0066] The present invention is not limited to the above-described embodiment. In the optically excited magnetic sensor module 1, the pump light L1 may excite the alkali metal vapor inside the cell 11. Therefore, the probe light L2 may also serve as the pump light L1, or the pump light L1 and the probe light L2 may share an incident region and an exit region in the main body 11a. In other words, the main body 11a may have only one incident region and one exit region. As an example, the main body 11a may not include the incident region R8 and the exit region R9 of the pump light L1. In this case, the heat conduction member 12 may be continuously provided over the entire area of ​​the first surface 11c, the second surface 11d, the third surface 11e, the fourth surface 11f, the fifth surface 11g, and the sixth surface 11h of the main body 11a, excluding the incident region R6 of the probe light L2, which is the light passage region LR, and the exit region R7 of the probe light L2. As a result, the heat generated from the heater 13 is conducted to the entire outer surface 110 of the cell 11 via each surface of the heat conducting member 12, so that the cell 11 can be heated uniformly.

[0067] In the above-described embodiment, the protrusion 11b does not have to be covered by the heat conducting member 12. Specifically, the protrusion 11b does not have to be covered by the second surface 12d of the heat conducting member 12.

[0068] In the above-described embodiment, the heat conduction members 5 and 12 only need to be capable of conducting heat. In this embodiment, the heat conduction members 5 and 12 are graphite sheets. However, they may be non-magnetic non-metallic materials, such as silicon-based heat conduction sheets, acrylic-based heat conduction sheets, and highly thermally conductive resins such as thin-film polyimides. By using non-magnetic non-metallic materials as the heat conduction members, the influence of external magnetic fields can be reduced. As a result, the magnetic field in the measurement target can be measured with higher sensitivity.

[0069] In the above-described embodiment, it is sufficient that each of the heat conduction members 5 and 12 can cover the area where it is provided without any gaps. For example, each of the heat conduction members 5 and 12 is not limited to being an integrally formed sheet-like member, but may be each of a plurality of parts provided successively with respect to each other.

[0070] In the above-described embodiment, the optically excited magnetic sensor module 1 may include a light receiving element that receives the pump light L1 emitted from the emission region R9 of the pump light L1. This allows the attenuation of the pump light L1 to be monitored efficiently. As a result, the alkali metal vapor in the cell 11 can be excited more reliably.

[0071] In the above-described embodiment, the entrance region R6 and the exit region R7 of the probe light L2 may be larger than the laser diameter of the probe light L2. For example, if the laser diameter of the probe light L2 is 1 mm, the entrance region R6 and the exit region R7 of the probe light L2 may be rectangular with sides of 1 mm or circular with a diameter of 1 mm.

[0072] In the above-described embodiment, the longer the width W5 of the long sides of the entrance region R8 and the exit region R9 of the pump light L1, the more reliably the metal vapor contained in the optical path of the probe light L2 is excited by the pump light L1. Therefore, the width W5 of the long sides of the entrance region R8 and the exit region R9 of the pump light L1 only needs to be equal to or less than the width W1 along the X direction of the main body 11a.

[0073] In the above-described embodiment, the width W5 of the short sides of the entrance region R8 and the exit region R9 of the pump light L1 may be larger than the laser diameter of the pump light L1. For example, if the laser diameter of the pump light L1 is 1 mm, the width W5 of the short sides of the entrance region R8 and the exit region R9 of the pump light L1 may be 1 mm or more.

[0074] In the above-described embodiment, the larger the entrance region R6 and exit region R7 of the probe light L2 and the entrance region R8 and exit region R9 of the pump light L1 are, the lower the temperature in each of the above regions becomes, impairing the uniformity of heating in the cell 11. Therefore, the area of ​​each of the above regions may be reduced while maintaining a state in which the probe light L2 or the pump light L1 can pass through each of the above regions.

[0075] In the above-described embodiment, the heater 13 and the temperature detection unit 14 only need to be in contact with the heat conduction member 12, and therefore may be formed on any of the first surface 12c, the second surface 12d, the third surface 12e, the fourth surface 12f, the fifth surface 12g, and the sixth surface 12h.

[0076] In the above-described embodiment, the heater 13 may be provided on the entrance region R6 of the probe light L2, the exit region R7 of the probe light L2, the entrance region R8 of the pump light L1, or the exit region R9 of the pump light L1, as long as the heater 13 is optically transparent.

[0077] In the above-described embodiment, it is sufficient that the heat conducted to the heat conduction member 5 is prevented from being conducted to the first light receiving element 49a and the second light receiving element 49b. Therefore, it is sufficient that the heat conduction member 5 is not provided in at least the region corresponding to the first light receiving element 49a (light receiving element) and the second light receiving element 49b (light receiving element). For example, the heat conduction member 5 does not have to be provided in the region corresponding to the first light receiving element 49a and the second light receiving element 49b on the inner surfaces 22a, 22b, 22c, and 22d of the housing 2. In other words, the heat conduction member 5 may be provided in the region of the inner surfaces 22a, 22b, 22c, and 22d of the housing 2 excluding the region corresponding only to the first light receiving element 49a and the second light receiving element 49b. Specifically, when viewed in the thickness direction of a certain second wall portion 22, the heat conduction member 5 may be provided in a region excluding the region overlapping with the first light receiving element 49a and the second light receiving element 49b on the inner surfaces 22a, 22b, 22c, and 22d of the second wall portion 22. More specifically, the second portion 52a may be provided in a region excluding the region facing the first light receiving element 49a and the second light receiving element 49b on the inner surface 22a, and the second portion 52b may be provided in a region excluding the region facing the first light receiving element 49a and the second light receiving element 49b on the inner surface 22b. [Explanation of symbols]

[0078] 1...photoexcited magnetic sensor module, 2...housing, 5...thermal conductive member (second thermal conductive member), 6...wiring, 7...support, 10...cell unit, 11...cell, 11a...main body, 12...thermal conductive member (first thermal conductive member), 13...heater, 15...insulating member, 16...opening, 16a...probe light entrance opening, 16b...probe light exit opening, 16c...pump light entrance opening, 16d...pump light exit opening, 21...first wall portion (wall portion), 21a...inner surface, 22... Second wall portion, 22a, 22b, 22c, 22d...inner surface, 47...light receiving unit, 48...substrate, 49a...first light receiving element (light receiving element), 49b...second light receiving element (light receiving element), 61...intermediate portion (part), 110...outer surface, L1...pump light, L2...probe light, LR...light passing region, R1, R2, R3, R4, R5...region, R6...probe light entrance region, R7...probe light exit region, R8...pump light entrance region, R9...pump light exit region.

Claims

1. The housing and a cell unit disposed within the housing; a second heat conduction member disposed within the housing, The cell unit comprises: a cell in which an alkali metal is sealed; a first heat conducting member covering the cell; a heater provided on the first thermal conductive member, the cell includes a body having a light passage region through which at least one of pump light and probe light passes; the first heat conduction member is provided continuously over the entire outer surface of the main body except for the light passage area, The second heat conducting member is provided on the inner surface of the housing.

2. a light-receiving element disposed in the housing and configured to receive the probe light emitted from the cell; 2. The photoexcited magnetic sensor module according to claim 1, wherein the second heat conducting member is not provided in an area of ​​the inner surface of the housing that corresponds to the light receiving element.

3. Further comprising a substrate on which the light receiving element is mounted, 3. The optically excited magnetic sensor module according to claim 2, wherein the second heat conducting member is not provided in an area of ​​the inner surface of the housing that corresponds to the light receiving element and the substrate.

4. the light passing region includes an incident region of the pump light, an incident region of the probe light, and an exit region of the probe light facing the incident region of the probe light in a second direction perpendicular to a first direction in which the pump light is incident on the incident region of the pump light, An optically excited magnetic sensor module as described in any one of claims 1 to 3, wherein the width of the entrance region of the pump light in a third direction perpendicular to both the first direction and the second direction is larger than the widths of the entrance region and the exit region of the probe light in the third direction.

5. A housing, a cell unit disposed in the housing, The cell unit comprises: a cell in which an alkali metal is sealed; a first heat conducting member covering the cell; a heater provided on the first thermal conductive member, the cell includes a body having a light passage region through which at least one of pump light and probe light passes; the first heat conduction member is provided continuously over the entire outer surface of the main body except for the light passage area, the light passing region includes an incident region of the pump light, an incident region of the probe light, and an exit region of the probe light facing the incident region of the probe light in a second direction perpendicular to a first direction in which the pump light is incident on the incident region of the pump light, An optically excited magnetic sensor module, wherein the width of the entrance region of the pump light in a third direction perpendicular to both the first direction and the second direction is larger than the widths of the entrance region and the exit region of the probe light in the third direction.

6. 6. The optically excited magnetic sensor module according to claim 4, wherein an area of ​​the entrance region of the pump light is larger than each of areas of the entrance region and the exit region of the probe light.

7. The first heat conduction member has an opening corresponding to the light passage area, the cell unit further includes a heat insulating member covering the first heat conducting member and the heater, 7. The optically excited magnetic sensor module according to claim 1, wherein the heat insulating member is provided on the entire first heat conducting member except for the opening.

8. 8. The optically excited magnetic sensor module according to claim 1, further comprising a support disposed within the housing for positioning the cell unit at a predetermined position within the housing.

9. The housing has a wall portion, An optically excited magnetic sensor module according to any one of claims 1 to 8, wherein the cell unit is arranged within the housing so that no space is formed between the wall portion and the cell unit.

Images