Development of laser subsystem for OSCAR-QUBE sensor: testing and characterization of performance in pulsed and continuous-wave operation

Abstract

Since the early 20th century, physicists have been interested in the real-world applications of quantum technologies such as quantum sensing. The Nitrogen-Vacancy (NV) centers in diamonds are promising opto-magnetic probes acting as solid-state qubits while operating at room temperatures. Green Laser light excites the NV centers, leading to the release of photons that enable the electron spin-state readout. Magnetic fields can alter the spin-state resulting in changes in photoluminescent intensity. This thesis focuses on designing, developing, testing, and characterizing the laser subsystem for an NV diamond-based magnetometer.

The approach is to design a PCB integrated laser subsystem that enables both the Optical and Photoelectric Detection of Magnetic Resonance (ODMR/PDMR) readout methods. Output power stability and thermal stability are crucial to use these techniques for measurements in both continuous wave and pulsed operation modes. The 520 nm laser offers a power output ranging from 0 to 50 mW, pulse widths down to 10 ns, and 1.5 ns rise and fall times. The standard deviation on the output power is less than 0.5%, implying the system is stable. Operational temperatures at maximum power do not exceed 43 °C and 66 °C for ambient and vacuum environments, respectively.

This work is part of the student project OSCAR-QUBE, within the framework of the "Orbit Your Thesis!" program organized by the European Space Agency and will fly onboard the international space station in 2021-2022.