Integrated photonics magnetometer based on a nonlinear diamond-containing resonator
A photonics device for threshold magnetometry includes an absorbent material with nonlinear optical susceptibility, such as a diamond material with nitrogen vacancy defects, that is disposed in an optical resonator. The optical resonator receives light from an input source and includes nonlinear optical properties that enable the resonator to undergo a nonlinear photon generation process at a certain threshold power level to generate photons at distinct frequencies from the input light. The absorbent material absorbs photons entering the resonator when excited, which causes the threshold power level to shift as a function of the absorption. This may cause the optical resonator to stop generating photons via the nonlinear photon generation process and output a change in power. The change in power can be used to determine the characteristics of a present magnetic field.
1. A device, comprising:
a substrate;
at least one optical pathway disposed on the substrate and configured to receive light having a first frequency;
a first optical resonator having nonlinear photon generation properties coupled to the at least one optical pathway, wherein the first optical resonator is configured to increase an intensity of the light having the first frequency, wherein when the intensity of the light having the first frequency exceeds a first threshold power level, the first optical resonator undergoes a nonlinear photon generation process to generate photons at a second frequency different from the first frequency, wherein the at least one optical pathway is configured to couple the light having the second frequency out of the first optical resonator at an output power level and to couple the light having the second frequency out of the substrate; and
an absorbent material disposed in the first optical resonator, wherein the absorbent material is configured, in response to being excited by light having a third frequency that corresponds to an excitation frequency of the absorbent material, to absorb the light having the first frequency, wherein the absorbent material has a nonlinear optical susceptibility such that, by absorbing the light having the first frequency, the absorbent material is configured to adjust a threshold power level needed for the first optical resonator to undergo the nonlinear photon generation process from the first threshold power level to a second threshold power level higher than the first threshold power level,
wherein when the intensity of the light having the first frequency is below the second threshold power level, the first optical resonator is not able to generate light having the second frequency,
wherein the output power level of the light having the second frequency that is coupled out of the first optical resonator decreases in response to the intensity of the light having the first frequency being below the second threshold power level.
2. The device of claim 1 , wherein the absorbent material is a diamond-based absorbent material that includes nitrogen-vacancy point defects.
3. The device of claim 1 , comprising a second optical resonator coupled to the at least one optical pathway, wherein the second optical resonator is configured to filter the light coupled out of the first optical resonator at the second frequency.
4. The device of claim 3 , wherein at least one of the first optical resonator or the second optical resonator comprises at least one heating element configured to control an optical path length of the first optical resonator or the second optical resonator.
5. The device of claim 1 , wherein the nonlinear photon generation process includes a Stimulated Brillouin Scattering (SBS) process, or an optical frequency comb generation process.
6. The device of claim 1 , wherein the first optical resonator is an optical parametric oscillator.
7. A system, comprising:
a first laser configured to transmit light at a first frequency;
a photonics circuit coupled to the first laser, the photonics circuit comprising:
a substrate;
at least one optical pathway disposed on the substrate and configured to receive the light at the first frequency;
a first optical resonator having nonlinear photon generation properties coupled to the at least one optical pathway, wherein the first optical resonator is configured to increase an intensity of the light at the first frequency, wherein when the intensity of the light at the first frequency exceeds a first threshold power level, the first optical resonator undergoes a nonlinear photon generation process to generate photons at a second frequency different from the first frequency, wherein the at least one optical pathway is configured to couple the light having the second frequency out of the first optical resonator at an output power level and to couple the light having the second frequency out of the substrate;
an absorbent material disposed in the first optical resonator, wherein the absorbent material is configured, in response to being excited by light having a third frequency that corresponds to an excitation frequency of the absorbent material, to absorb the light having the first frequency, wherein the absorbent material has a nonlinear optical susceptibility such that, by absorbing the light having the first frequency, the absorbent material is configured to adjust a threshold power level needed for the first optical resonator to undergo the nonlinear photon generation process from the first threshold power level to a second threshold power level higher than the first threshold power level,
wherein when the intensity of the light having the first frequency is below the second threshold power level, the first optical resonator is not able to generate light having the second frequency,
a detector coupled to the at least one optical pathway and configured to detect the light having the second frequency at the output power level;
an electromagnetic transmitter coupled to the absorbent material, wherein the electromagnetic transmitter is configured to transmit a frequency-varied electromagnetic wave to the absorbent material that varies over a frequency range; and
at least one processor coupled to the detector, wherein the at least one processor is configured to determine a characteristic of a magnetic field in response to a change in the output power level.
8. The system of claim 7 , comprising a pump laser coupled to the absorbent material, wherein the pump laser is configured to excite the absorbent material by transmitting light at the third frequency that corresponds to the excitation frequency of the absorbent material.
9. The system of claim 8 , wherein the detector is configured to detect a change in the output power level of the light at the second frequency in response to the intensity of the light at the first frequency falling below the threshold power level.
10. The system of claim 7 , wherein to determine a characteristic of a magnetic field in response to a change in the output power level comprises:
determine one or more frequencies in the frequency range that correspond to the change in the output power level; and
determine a characteristic of a magnetic field based on the one or more frequencies in the frequency range.
11. The system of claim 7 , wherein the absorbent material is configured to absorb light at the third frequency at an absorption rate that changes as a function of the frequency-varied electromagnetic wave.
12. The system of claim 7 , comprising a second optical resonator coupled to the at least one optical pathway, wherein the second optical resonator is configured to filter the light coupled out of the first optical resonator at the second frequency.
13. The system of claim 12 , wherein the absorbent material is configured to cause the first optical resonator to stop generating light at the second frequency when the absorbent material reduces the intensity of the light at the first frequency to an intensity below the threshold power level.
14. The system of claim 7 , wherein the absorbent material is a diamond-based material that includes nitrogen vacancy defects.
15. A method, comprising:
receiving, at a first optical resonator, light having a first frequency;
generating, by the first optical resonator, light having a second frequency in response to an intensity of the light having the first frequency exceeding a first threshold power level;
absorbing, by an absorbent material disposed in the first optical resonator, the light having the first frequency in response to receiving light having a third frequency that corresponds to an excitation frequency of the absorbent material, wherein the absorbent material has a nonlinear optical susceptibility such that, by absorbing the light having the first frequency, the absorbent material is configured to adjust a threshold power level needed for the first optical resonator to generate light having the second frequency from the first threshold power level to a second threshold power level higher than the first threshold power level;
detecting a change in output power level of the first optical resonator in response to the light at the first frequency being absorbed;
determining a characteristic of a magnetic field in response to the change in output power.
16. The method of claim 15 , comprising:
transmitting a frequency-varied electromagnetic wave that varies over a frequency range; and
absorbing, by the absorbent material, light having the first frequency at an absorption rate that changes as a function of the frequency-varied electromagnetic wave.
17. The method of claim 15 , wherein generating light having a second frequency in response to an intensity of the light having the first frequency exceeding a threshold power level comprises generating the light having a second frequency with a nonlinear photon generation process based on nonlinear optical properties of the first optical resonator, wherein the nonlinear photon generation process includes a Stimulated Brillouin Scattering (SBS) process or an optical frequency comb process.
18. The method of claim 15 , comprising exciting, by a pump laser coupled to the absorbent material, the absorbent material by transmitting light at the second frequency that corresponds to the excitation frequency of the absorbent material.
19. The method of claim 15 , wherein absorbing the light having the first frequency comprises absorbing the light from a diamond-based material that includes nitrogen point vacancies.
20. The method of claim 15 , comprising transmitting a frequency-varied electromagnetic wave to the absorbent material that varies over a frequency range; and wherein determining a characteristic of a magnetic field in response to the change in output power comprises:
determining one or more frequencies in the frequency range that correspond to the change in output power of the first optical resonator; and
determining a characteristic of a magnetic field based on the one or more frequencies in the frequency range.