Lightweight NV Diamond CW-ODMR Magnetometer and Application
By Eric, Harry, Isaac
The proposed research will aim to utilize Nitrogen Vacancy (NV)-Diamond based Continuous Wave- Optically Detected Magnetic Resonance (CW-ODMR) Magnetometers to measure magnetic fields with targeted sensitivity. The proposed NV-Diamonds to be used in the contraption will be grown in the lab. Ideally, the research will utilize two different NV diamonds: one grown from a seed diamond in the lab and one obtained from an industrial source to compare their performance in the magnetometer. Once a magnetometer has been constructed, we will apply it in a small scale GPS scenario within TJHSST, where we will attempt to map out the magnetic field throughout TJ and use subsequent data for positioning within the campus. This application will serve as a proof-of-concept for a larger scale implementation of the device.
The intellectual merit of this experiment stems from a recent paper by Bulau, Walter, and Fritz published in August of 2025 that details the creation of a low-cost CW-ODMR Magnetometer. A typical Magnetometer requires a light source, color filter, TIA (Transimpedance amplifier), a microwave structure, and microwave generator. Bulau et al. opted to use an LED (instead of the traditional laser) as a light source, a single stage TIA from Texas Instruments, and a low cost microwave generator. Their results prove promising for a low cost ,lightweight, and compact contraption to serve as a magnetometer. The researchers have also proposed various strategies to improve the measurements and capacity of the setup, including by using higher quality diamonds, using a smaller microwave resonator, and possibly adding shielding around the device. The magnetometer produced through this project will then be put to use in a magnetic mapping algorithm via Gaussian Processes to interpolate discrete measurements over a continuous field. This will allow a measurement at any single place in the field to be placed on the magnetic field map. Meanwhile, one of the diamonds to be used in the magnetometer will be a seed diamond grown in the lab. The growth of a seed diamond in the lab will be cheaper than if a fully grown NV diamond were obtained from an outside source, making it an appealing option. The seed diamond will be grown using either methods detailed by Kunuku, which utilize high pressure and temperature chambers to bombard the seed diamond with CH4 or with methods detailed by Karki, which involves using an alternative method with UV radiation instead. The intellectual merit of growing and fabricating our own NV diamond from a seed diamond would allow us to learn and gain more experience with baking carbon in an oven; then, we can publish on it so that the greater public will also be able to take advantage of our newly gained knowledge.
The broader impacts of NV-diamond production method is its instrumental applications in CW- ODRM detection, while keeping NV-diamond production costs low. Additionally, reliably being able to grow and cut seed NV diamonds into ones usable for experiment and application will allow for more affordable NV diamond experiments, increasing accessibility in educational programs around the world. Meanwhile, the broader impacts of a lightweight magnetometer and sensitive measurement of Earth’s magnetic fields cannot be overstated. This research has particularly promising applications for navigation in areas without satellite signals or data access. Xuezhi Wang et al. devised a mathematical model for fitting the Earth’s magnetic fields to a position on the globe using magnetometry. Their algorithm, though error prone, shows a promising, relatively accurate method to apply magnetometry to navigation. A system similar to that described in this research would be compatible with their algorithm, if implemented correctly. The resulting overall system would allow positioning on the globe via sensitive detection of the Earth’s magnetic field, allowing any user to place themselves on the globe without access to traditional satellite based systems.