Robust All-Optical Solid-State Magnetometer for Space

Magnetometers are key components of space missions, used for navigation and orientation, sensing planetary magnetic fields and other functions. State-of-art (SOA) magnetometers like fluxgates and helium vector magnetometers have been essential for space exploration and scientific missions, providing valuable data about magnetic fields in space and on planets. They have significantly enhanced our understanding of the solar system's evolution. Magnetometers also play a crucial role in attitude sensing and magnetic geological mapping. Quantum sensors, particularly for magnetometry, have been ranked by NASA (i.e., NASA Civil Space Shortfalls Item #1599) as a promising technology for future space and aviation missions. Systems are highly desired that are simple, ultracompact, highly sensitive, resistant to drift, and stable and robust under swings of temperature (-50 to 250C), radiation and platform noise and vibration. We identify optimal conditions for low-field all-optical diamond nitrogen vacancy (DNV) sensing compared to conventional optically detected magnetic resonance (ODMR) techniques, enabling new applications using all-optical (AO) measurements with less system complexity, size, weight, and power (SWaP). This approach is attractive due to broad sample compatibility, reduced experimental complexity, and inherent robustness to high temperature and radiation. Our AO diode-based vector magnetometer uses no lasers, no microwaves and no signal generators. Its sensitivity (<20 pT/rtHz), accuracy (<1 nT) bandwidth (>500 Hz) and dynamic range (+/- 100 uT) competes with current fluxgates, but with simpler design in smaller footprint (volume < 1 liter, mass < 1 kg and power < 0.5W) that self-calibrates a tri-axial vector measurement based on DNV hyperfine splitting, providing long-term stability. This approach simplifies the system, mitigates need for multiple independent sensors and booms, and resets the engineering trade between magnetometer performance and SWaP.