Oscillation module and atomic oscillator

Abstract

To realize an atomic oscillator with high accuracy which is small in size and low in power consumption.SOLUTION: An oscillation module 10 includes a substrate 11 having complex defects of impurities and vacancies, a plurality of electrodes 13 provided on the substrate 11 and generating an electric field by applying a voltage, a light source 17 that irradiates the substrate 11 with excitation light that excites the complex defects, and a photodetector 4 that detects fluorescence emitted from the substrate 11. By using such an oscillation module 10, an atomic oscillator 1 with high accuracy which is small in size and low in power consumption can be realized.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an oscillation module and an atomic oscillator. [Background technology]

[0002] Conventionally, atomic oscillators with various configurations have been used. Examples of such atomic oscillators include atomic oscillators using gas cells filled with alkali metals such as cesium and rubidium. While atomic oscillators using gas cells are highly accurate, the use of gas-filled gas cells tends to result in large size, high power consumption, and high cost. Therefore, for example, Patent Document 1 proposes a solid-state atomic clock device that generates a clock frequency signal based on the hyperfine structure of color centers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-526744 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, a typical color center is a nitrogen-vacancy center in a diamond crystal. However, unlike cesium or rubidium in a gas cell, the nitrogen-vacancy center in a diamond crystal does not have an energy level that is less susceptible to magnetic field fluctuations. Therefore, in an atomic oscillator using a nitrogen-vacancy center in a diamond crystal, such as that disclosed in Patent Document 1, the energy level fluctuates greatly due to the influence of geomagnetism, etc., which can make it difficult to oscillate at a stable frequency. [Means for solving the problem]

[0005] The oscillation module of the present invention, which solves the above problem, is characterized by comprising a substrate having a complex defect of an impurity and a vacancy, a plurality of electrodes provided on the substrate and generating an electric field by applying a voltage, a light source that irradiates the substrate with excitation light that excites the complex defect, and a photodetector that detects fluorescence emitted from the substrate. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an atomic oscillator according to an embodiment of the present invention. [Figure 2] 2 is a diagram showing an oscillation module that can be used in the atomic oscillator of FIG. 1. [Figure 3] 3 is a diagram showing an oscillation module having a different configuration from the oscillation module of FIG. 2 that can be used in the atomic oscillator of FIG. 1; [Figure 4] 1 is a graph showing the magnetic field dependence of the energy level of a nitrogen-vacancy center in a diamond crystal under conditions in which no electric field exists in the atomic oscillator of this embodiment. [Figure 5] 10 is a graph showing the magnetic field dependence of the energy level of cesium atoms in a reference atomic oscillator using a gas cell. [Figure 6] 1 is a graph showing the magnetic field dependence of the energy level of a nitrogen-vacancy center in a diamond crystal under conditions in which an electric field is present in the atomic oscillator of this embodiment. [Figure 7] Diagram to explain the spin Hamiltonian when an electric field and a magnetic field are applied to the nitrogen-vacancy center in a diamond crystal. DETAILED DESCRIPTION OF THE INVENTION

[0007] First, the present invention will be briefly described. The oscillation module of the first aspect of the present invention for solving the above problem is characterized by comprising: a substrate having a complex defect of an impurity and a vacancy; a plurality of electrodes provided on the substrate for generating an electric field by applying a voltage; a light source for irradiating the substrate with excitation light that excites the complex defect; and a photodetector for detecting fluorescence emitted from the substrate.

[0008] According to this aspect, a device includes a substrate having complex defects of impurities and vacancies, a plurality of electrodes provided on the substrate and configured to generate an electric field by applying a voltage to the electrodes, a light source configured to irradiate the substrate with excitation light that excites the complex defects, and a photodetector configured to detect fluorescence emitted from the substrate. This configuration eliminates the need for a gas, resulting in a compact, low-power configuration, while generating an electric field in the substrate to suppress the magnetic field dependence of the energy levels of the complex defects of impurities and vacancies, thereby enabling stable frequency oscillation, i.e., high-precision oscillation, with the magnetic field dependence suppressed.

[0009] An oscillation module according to a second aspect of the present invention is an aspect dependent on the first aspect, characterized in that the substrate is a diamond substrate having a nitrogen-vacancy center as the complex defect.

[0010] According to this aspect, the substrate is a diamond substrate having a nitrogen-vacancy center as a complex defect. With this configuration, an oscillation module can be provided that realizes a small, low-power, and high-precision atomic oscillator.

[0011] An oscillation module according to a third aspect of the present invention is an aspect dependent on the first aspect, and is characterized by including a microwave generating unit that generates microwaves based on an input signal input from the outside.

[0012] According to this aspect, the microwave generating unit is provided to generate microwaves based on an input signal input from outside. With this configuration, the microwaves can be converted into electromagnetic waves in the microwave region that serve as a reference signal, and a decrease in frequency stability can be suitably suppressed.

[0013] An oscillation module according to a fourth aspect of the present invention is an aspect dependent on the third aspect, and is characterized in that the microwave generating section is provided on the substrate.

[0014] According to this aspect, the microwave generating unit is provided on the substrate, and this configuration allows suitable conversion into electromagnetic waves in the microwave range.

[0015] An oscillation module according to a fifth aspect of the present invention is an aspect dependent on the fourth aspect, and is characterized in that the microwave generating section is provided between the electrodes.

[0016] According to this aspect, the microwave generating unit is provided between the electrodes. With this configuration, it is possible to particularly suitably convert the microwave into an electromagnetic wave in the microwave region.

[0017] An oscillation module according to a sixth aspect of the present invention is an aspect dependent on the fifth aspect, characterized in that the microwave generating section is a coiled or straight electric wire.

[0018] According to this aspect, the microwave generating unit is a coiled or straight electric wire, which allows the microwave generating unit to have a simple configuration and a small size.

[0019] An oscillation module according to a seventh aspect of the present invention is an aspect dependent on the first aspect, characterized in that the voltage applied to the electrodes is a DC voltage.

[0020] According to this aspect, the voltage applied to the electrodes is a DC voltage, and this configuration makes it possible to particularly stabilize the oscillation frequency.

[0021] An atomic oscillator according to an eighth aspect of the present invention is characterized by comprising: an oscillation module according to any one of the first to seventh aspects; a feedback circuit that generates a feedback signal based on a detection signal output from the photodetector; an oscillator that adjusts an oscillation frequency based on the feedback signal; and a frequency multiplication circuit that multiplies the oscillation frequency of the oscillator and generates an input signal to be input to the oscillation module.

[0022] According to this aspect, an atomic oscillator having a small size, low power consumption, and high accuracy can be realized by including the above-mentioned oscillation module, a feedback circuit that generates a feedback signal based on the detection signal output from the photodetector, an oscillator that adjusts the oscillation frequency based on the feedback signal, and a frequency multiplication circuit that multiplies the oscillation frequency of the oscillator and generates an input signal to be input to the oscillation module.

[0023] An atomic oscillator according to a ninth aspect of the present invention is an aspect dependent on the eighth aspect, characterized in that the oscillation module is an all-solid-state atomic oscillator in which each component is made of a solid.

[0024] According to this aspect, the oscillation module is an all-solid-state atomic oscillator whose constituent members are made of solids. With this configuration, it is possible to realize a particularly suitable small-sized, low-power-consumption, and high-precision atomic oscillator.

[0025] Hereinafter, an atomic oscillator 1 according to one embodiment of the present invention and an oscillation module 10 that can be used with the atomic oscillator 1 will be described with reference to the accompanying drawings. First, the device configuration of the atomic oscillator 1 of this embodiment will be described with reference to FIG. 1. The device configuration of the atomic oscillator 1 of this embodiment follows the configuration of a general cesium or rubidium atomic oscillator. Specifically, except that an oscillation module 10, which is an all-solid-state atomic oscillator described later, is used instead of an atomic oscillator using a gas cell, the configuration is almost the same as that of a general cesium or rubidium atomic oscillator.

[0026] In the atomic oscillator 1 of this embodiment, a signal S to be output to the outside is oscillated by a controlled oscillator 2. Specifically, the controlled oscillator 2 is assumed to be a crystal oscillator such as a temperature compensated crystal oscillator (TCXO), and the frequency of the signal S is assumed to be about 1 to 10 MHz, for example, 10 MHz.

[0027] Here, a quartz crystal oscillator may experience frequency drift over time, i.e., a gradual change in frequency over a certain period of time. Therefore, it is preferable to prepare a reference frequency and use the reference frequency to feedback correct the oscillation frequency. A commonly used reference frequency in the past has been 9.2 GHz, which is the frequency of the hyperfine structure transition of cesium. On the other hand, in the atomic oscillator 1 of this embodiment, this reference frequency is replaced with 2.87 GHz, which is the resonance frequency of the NV center in diamond (nitrogen-vacancy center in diamond crystal).

[0028] That is, in the atomic oscillator 1 of this embodiment, the oscillation module 10 corresponding to the atomic oscillator section has been replaced with one using diamond, rather than the conventional one using cesium or the like. Since NV centers in diamond also emit fluorescence like cesium, the change in fluorescence intensity can be converted into a frequency shift amount and the quartz oscillator can be corrected. As mentioned above, the resonant frequency of the NV center in diamond is approximately 2.87 GHz, so the oscillation frequency of the quartz oscillator needs to be multiplied. Therefore, the atomic oscillator 1 of this embodiment is provided with a frequency multiplication circuit 3.

[0029] Here, nitrogen-vacancy centers in diamond crystals are a type of defect that exists naturally or is artificially synthesized in diamond crystals. NV centers have a structure in which one carbon atom is substituted with nitrogen and the adjacent carbon atom is substituted with a vacancy, and they are being studied for applications in various sensors, etc. Because the energy level of NV centers exists within the deep band gap of diamond, they can be considered as if they were an isolated atom, like cesium or rubidium.

[0030] Furthermore, the fluorescence detector 4 in Fig. 1 is for detecting changes in the fluorescence intensity of the NV center in the diamond. The fluorescence detector 4 can also be considered as a photodetector that constitutes part of the oscillation module 10. As shown in Fig. 1, the atomic oscillator 1 of this embodiment is configured to be able to perform frequency feedback using a feedback circuit 5 based on the amount of fluorescence detected by the fluorescence detector 4. In the atomic oscillator 1 of this embodiment, the signal S is sent in the direction of the arrow in Fig. 1 to perform frequency feedback while transmitting the signal S to the outside.

[0031] Next, an example of an oscillation module 10 that can be used in the atomic oscillator 1 of this embodiment will be described with reference to FIGS. 2 and 3. First, with reference to FIG. 2, an oscillation module 10A out of the oscillation modules 10 that can be used in the atomic oscillator 1 of this embodiment will be described. The oscillation module 10A is an example of an all-solid-state atomic oscillator in which each component is made of a solid, and an electrode 13 is formed on a diamond substrate 11 that contains nitrogen-vacancy centers in a diamond crystal. The electrode 13 includes a plurality of electrodes 13A and 13B for generating an electric field by applying a voltage, i.e., for applying an electric field. In addition, a nitrogen-vacancy center-containing layer (NV-containing layer 12) in a diamond crystal is present on the diamond substrate 11.

[0032] The oscillator module 10A applies microwaves, which serve as a reference signal for generating a reference frequency, via a coil 15A (coiled electric wire) serving as a microwave generator 15. To detect nitrogen-vacancy centers in the diamond crystal, the oscillator module 10A irradiates green light L1 from a laser or other light source 17 via a lens 14, for example. Red fluorescence L2 emitted from the nitrogen-vacancy centers in the diamond crystal is then discriminated by a dichroic mirror 16, whose reflection and transmission characteristics change depending on wavelength, and guided to the fluorescence detector 4. The atomic oscillator 1 of this embodiment shown in FIG. 1 performs frequency feedback via a feedback circuit 5 based on the amount of fluorescence detected by the fluorescence detector 4. If necessary, an electrostatic or magnetic shield may be used to block noise from the external environment.

[0033] Because it is important to apply uniform microwaves and electric fields to the nitrogen-vacancy center in the diamond crystal, it is desirable that the nitrogen-vacancy center to be measured be near the center of the coil 15A and near the center of the electrode 13. Therefore, the light used to excite and measure the nitrogen-vacancy center in the diamond crystal is also emitted near the center of the coil 15A and the electrode 13. The electric field generated by applying a voltage to the electrode 13 must have a component in a plane perpendicular to the axis connecting the nitrogen and vacancy in the nitrogen-vacancy center in the diamond crystal. Therefore, in a configuration such as the oscillation module 10A, it is desirable that the diamond have a (111) plane orientation.

[0034] In principle, it is sufficient if there is at least one nitrogen-vacancy center in the diamond crystal within the irradiation range of the green light L1. However, in order to increase the S / N ratio, which is the ratio of sensor output to noise, it is also possible to measure nitrogen-vacancy centers in many diamond crystals at once. Typical values for the diamond substrate 11, etc. are listed below. The size of the diamond substrate 11 is preferably several mm square. However, this size is not necessarily required, as it is a size that is often used in research. The thickness of the NV-containing layer 12 is preferably 1 to 100 μm. The concentration of nitrogen-vacancy centers in the diamond crystal should be 10 15 ~10 18 pieces / cm 3 The wavelength of the green light L1 is preferably about 532 nm. The intensity of the green light L1 is preferably about 10 μW to several hundred mW. The applied electric field intensity is preferably about 10 5 ~10 8 It is preferable that the value is about V / m.

[0035] Next, with reference to Fig. 3, an oscillation module 10B out of the oscillation modules 10 that can be used in the atomic oscillator 1 of this embodiment will be described. Like the oscillation module 10A, the oscillation module 10B also has an electrode 13 formed on a diamond substrate 11 that contains nitrogen-vacancy centers in the diamond crystal, and an electric field can be generated by applying a voltage to the electrode 13. In the oscillation module 10B, a microwave that serves as a reference signal is applied by a thin wire 15B, such as a straight electric wire made of copper, that serves as the microwave generating unit 15.

[0036] Like the oscillation module 10A, the oscillation module 10B also irradiates green light L1 from a laser or other light source 17 to detect nitrogen-vacancy centers in the diamond crystal. However, in the oscillation module 10B, the green light L1 from the light source 17 is irradiated from the backside of the diamond substrate 11 and is totally reflected. Red fluorescence L2 emitted from the nitrogen-vacancy centers in the diamond crystal toward the surface of the diamond substrate 11 is guided to the fluorescence detector 4 via a lens 14 or the like. Although not shown in the figure, a bandpass filter that transmits red light is installed between the lens L2 and the detector 4. The atomic oscillator 1 of this embodiment shown in Figure 1 performs frequency feedback via a feedback circuit 5 based on the amount of fluorescence detected by the fluorescence detector 4. If necessary, an electrostatic or magnetic shield may be used to block noise from the external environment.

[0037] As described above, oscillation module 10A and oscillation module 10B are configured to have microwave generating unit 15 and apply microwaves. However, the present invention is not limited to this configuration. For example, microwaves may be applied using a microwave resonator such as a loop-gap resonator. Furthermore, instead of applying microwaves, a configuration may be used in which two lasers with different frequencies are incident to generate CPT (Coherent Population Trapping).

[0038] As described above, the atomic oscillator 1 of this embodiment is configured to be able to apply an electric field by the electrodes 13. The application of an electric field improves the frequency accuracy. Next, the reason why the application of an electric field improves the frequency accuracy will be explained below.

[0039] First, consider the situation in which only a magnetic field is applied to the nitrogen-vacancy center in the diamond crystal in the atomic oscillator 1 of this embodiment, and no electric field exists. At this time, the change in the energy level relative to the magnetic field is represented by a straight line with two slopes, as shown by the solid line in the graph of Figure 4, due to Zeeman splitting. This means that when the magnetic field fluctuates, the frequency also fluctuates accordingly. In other words, the smaller the slope of each of the two solid lines, the better the oscillator characteristics. In the graph of Figure 4, the dashed line represents the reference energy where the magnetic index is zero, which is insensitive to the magnetic field, and the difference between the solid line and the dashed line represents the energy utilization transition (the transition used as an oscillator), that is, 2.87 GHz, which is the resonant frequency of the NV center in diamond in the atomic oscillator 1 of this embodiment.

[0040] For example, an atomic oscillator with a gas cell using cesium or the like has higher accuracy and superior characteristics than an atomic oscillator using nitrogen-vacancy centers in a diamond crystal. This is because, in an atomic oscillator with a gas cell using cesium, the energy level changes only second-order with respect to the magnetic field near zero magnetic field, as shown by the solid line in the region R1 of the graph in Figure 5.

[0041] Therefore, in the atomic oscillator 1 of this embodiment, by applying an electric field to the nitrogen-vacancy center in the diamond crystal, the characteristics of the energy level with respect to the magnetic field are made closer to those of cesium. Figure 6 shows the energy level when a constant electric field is applied in addition to a magnetic field at the nitrogen-vacancy center in the diamond crystal of the atomic oscillator 1 of this embodiment. As is clear from Figure 6, in the presence of an electric field, the change in the energy level with respect to the magnetic field is no longer linear, and in the region R2, near zero magnetic field, the energy level changes only second-order with respect to the magnetic field. In other words, by applying an electric field to the nitrogen-vacancy center in the diamond crystal, it is possible to exhibit the same characteristics as an atomic oscillator with a gas cell using cesium.

[0042] However, the atomic oscillator 1 of this embodiment differs from the atomic oscillator of a gas cell using cesium in that, since an electric field is applied in the atomic oscillator 1 of this embodiment, fluctuations in this electric field will also cause fluctuations in frequency. For example, as shown in FIG. 6, in the atomic oscillator 1 of this embodiment, there is a risk that the energy utilization transition will differ from utilization transition A to utilization transition B. Therefore, in the atomic oscillator 1 of this embodiment, it is necessary to stably apply a constant electric field. Note that conventional methods can be used to stably apply a constant electric field.

[0043] That is, the atomic oscillator 1 of this embodiment is configured to generate an electric field in order to suppress fluctuations due to a magnetic field. Although there is a risk that fluctuations due to the electric field will occur when an electric field is generated, it is easier to suppress fluctuations due to the electric field than fluctuations due to a magnetic field. For this reason, the atomic oscillator 1 of this embodiment is configured to suppress fluctuations due to the electric field as much as possible.

[0044] Here, the spin Hamiltonian H when an electric field and a magnetic field are applied to the nitrogen-vacancy center in a diamond crystal is gs is given by the following equation 1.

[0045]

number

[0046] where h is the Planck constant, D gs is the zero-field splitting constant of the ground state (approximately 2.87 GHz), d gs || , d gs ⊥ are the quantization axes of the NV center, and the permanent electric dipole moments parallel and perpendicular to the axis connecting N and V, respectively, and Π x , Π y , Π Z are the components of the electric field when the x, y, and z axes are taken as shown in Figure 7, and S=(S x , S y , S z ) are the electron spin angular momentum operators, and B=(B x , B y , B z ) is the magnetic field. Also, S=1. Calculating the energy eigenvalues from this Hamiltonian gives two types of resonant frequencies expressed by the following equation 2. Plotting this equation 2 against the magnetic field B gives a solid line graph equivalent to Figure 6.

[0047]

number

[0048] To summarize from the perspective of the oscillation module 10, the oscillation module 10A and the oscillation module 10B of this embodiment include a diamond substrate 11, which is a substrate having complex defects of impurities and vacancies, a plurality of electrodes 13 provided on the diamond substrate 11 and generating an electric field by applying a voltage, a light source 17 that irradiates the diamond substrate 11 with excitation light that excites the complex defects, and a fluorescence detector 4 that detects fluorescence emitted from the diamond substrate 11. With this configuration, the oscillation module 10A and the oscillation module 10B of this embodiment can be made small and low-power consuming without the need to use gas, while generating an electric field in the diamond substrate 11 to suppress the magnetic field dependence of the energy levels of the complex defects of impurities and vacancies, thereby enabling stable frequency oscillation with suppressed magnetic field dependence, i.e., highly accurate oscillation.

[0049] In this example, the complex defects of impurities and vacancies are referred to as nitrogen-vacancy centers (NV) in the diamond crystal, and more specifically, negatively charged nitrogen-vacancy centers (NV - However, the present invention is not limited to such a structure. For example, a silicon-vacancy center (SiV) may be used.

[0050] Furthermore, the oscillation module 10A and the oscillation module 10B of this embodiment have a diamond substrate 11 having a nitrogen-vacancy center as a complex defect as a substrate. With this configuration, an oscillation module can be made to realize a suitably small, low-power consumption, and high-precision atomic oscillator. Note that although the diamond substrate 11 is used in this embodiment, the configuration is not limited to this. Any substrate having a wide band gap may be used, and for example, a silicon carbide (SiC) substrate may be used instead of the diamond substrate 11.

[0051] Furthermore, the oscillation module 10A and the oscillation module 10B of this embodiment include a microwave generating unit 15 that generates microwaves based on an input signal input from the outside. With this configuration, the oscillation module 10A and the oscillation module 10B of this embodiment can convert the microwaves into electromagnetic waves in the microwave region that serve as a reference signal, and can suitably suppress a decrease in frequency stability.

[0052] Furthermore, in the oscillation module 10A and the oscillation module 10B of this embodiment, the microwave generating unit 15 is provided on the diamond substrate 11. With this configuration, the oscillation module 10A and the oscillation module 10B of this embodiment can suitably convert microwaves into electromagnetic waves in the microwave region.

[0053] Furthermore, in the oscillation module 10A and the oscillation module 10B of this embodiment, the microwave generation unit 15 is provided between the two electrodes 13, that is, the electrode 13A and the electrode 13B. With this configuration, the oscillation module 10A and the oscillation module 10B of this embodiment can be particularly suitably converted into electromagnetic waves in the microwave region.

[0054] In the oscillation module 10A of this embodiment, the microwave generating unit 15 is a coil 15A that is a coiled electric wire. On the other hand, in the oscillation module 10B of this embodiment, the microwave generating unit is a thin wire 15B that is a straight electric wire. In this way, it is preferable that the microwave generating unit 15 is a coiled or straight electric wire. This is because such a configuration allows the microwave generating unit 15 to have a simple configuration and a small size.

[0055] In the oscillation modules 10A and 10B of this embodiment, a DC voltage is applied to the electrodes 13. With this configuration, the oscillation frequency can be particularly stabilized.

[0056] Next, we will summarize from the perspective of an atomic oscillator. The atomic oscillator 1 of this embodiment includes the above-mentioned oscillation module 10, a feedback circuit 5 that generates a feedback signal based on the detection signal output from the fluorescence detector 4, a controlled oscillator 2 as an oscillator that adjusts the oscillation frequency based on the feedback signal, and a frequency multiplication circuit 3 that multiplies the oscillation frequency of the controlled oscillator 2 and generates an input signal to be input to the oscillation module 10. With this configuration, the atomic oscillator 1 of this embodiment can be realized as a suitably small, low-power-consumption, and high-precision atomic oscillator.

[0057] Furthermore, both the oscillation module 10A and the oscillation module 10B of the atomic oscillator 1 of this embodiment are all-solid-state atomic oscillators in which each component is made of a solid. With this configuration, the atomic oscillator 1 of this embodiment can realize a particularly suitable small-sized, low-power-consumption, and high-precision atomic oscillator.

[0058] As described above, the technical features of the atomic oscillator 1 of this embodiment enable high-precision all-solid-state atomic oscillators. Furthermore, compared to atomic oscillators using gas cells, a compact, low-power, high-precision atomic oscillator can be realized. Furthermore, the technical features of the atomic oscillator 1 of this embodiment enable operation at room temperature, eliminating the need for heating like with gas cells, leading to lower power consumption. Furthermore, because it is all-solid-state, integration is easier than with gas cells, making it applicable to the realization of ultra-compact atomic oscillators. Applications include time synchronization, in-vehicle timing devices, high-precision positioning devices, and wristwatches. From another perspective, applying color centers in diamond to the oscillator facilitates miniaturization and integration compared to conventional atomic oscillators using gases. Furthermore, the heating mechanism required for conventional atomic oscillators can be eliminated. To address the potential problem of degraded frequency stability, applying a DC electric field from electrodes installed on the diamond substrate can change the nitrogen-vacancy centers in the diamond crystal to be insensitive to magnetic fields, thereby suppressing the deterioration of frequency stability due to magnetic field fluctuations in the external environment.

[0059] The present invention is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit of the present invention. The technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0060] 1... atomic oscillator, 2... controlled oscillator, 3... frequency multiplication circuit, 4... fluorescence detector (photoreceiver), 5... feedback circuit, 10... oscillation module, 10A... oscillation module, 10B... oscillation module, 11... diamond substrate (substrate), 12... NV-containing layer, 13... electrode, 13A... electrode, 13B... electrode, 14... lens, 15... microwave generator, 15A... coil, 15B... thin wire, 16... dichroic mirror, 17... light source, L1... green light, L2... red fluorescence, S... signal

Claims

1. a substrate having complex defects of impurities and vacancies; a plurality of electrodes provided on the substrate and configured to generate an electric field by applying a voltage thereto; a light source that irradiates the substrate with excitation light that excites the complex defects; a photodetector for detecting fluorescence emitted from the substrate; An oscillation module comprising:

2. 2. The oscillation module according to claim 1, The oscillation module is characterized in that the substrate is a diamond substrate having a nitrogen-vacancy center as the complex defect.

3. 2. The oscillation module according to claim 1, An oscillation module comprising a microwave generating section that generates microwaves based on an input signal input from an external source.

4. 4. The oscillation module according to claim 3, The oscillation module is characterized in that the microwave generating section is provided on the substrate.

5. 5. The oscillation module according to claim 4, The oscillation module is characterized in that the microwave generating section is provided between the electrodes.

6. 6. The oscillation module according to claim 5, The oscillation module is characterized in that the microwave generating section is a coiled or straight electric wire.

7. 2. The oscillation module according to claim 1, The oscillation module is characterized in that the voltage applied to the electrodes is a DC voltage.

8. The oscillation module according to any one of claims 1 to 7, a feedback circuit that generates a feedback signal based on the detection signal output from the optical receiver; an oscillator that adjusts an oscillation frequency based on the feedback signal; a frequency multiplication circuit that multiplies the oscillation frequency of the oscillator and generates an input signal to be input to the oscillation module; An atomic oscillator comprising:

9. 9. The atomic oscillator according to claim 8, The atomic oscillator is characterized in that the oscillation module is an all-solid-state atomic oscillator in which each component is made of a solid.

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