High-sensitivity spectroscopic measurements under pulsed high magnetic field

Pulsed magnet technology is the only way to generate ultra-strong magnetic fields higher than 45 T so far. However, the inherently fast-changing field strength (typically on the order of 1000 T/s) poses significant challenges for spectroscopic measurements which rely on time integration of signals to improve spectral qualities. In this work, we report high-sensitivity spectroscopic measurements under pulsed high magnetic fields employing the long flat-top pulsed magnetic field technique. By means of a multiple-capacitor power supply, we were able to generate pulsed high magnetic fields with controllable flat-top pulse width and field stabilities. By synchronizing spectroscopic measurements with the waveform of the flat-top magnetic field, the integration time of each spectrum can be increased by up to 100 times compared with that of the conventional spectroscopic measurements under pulsed magnetic fields, thus enabling high-sensitivity spectroscopic measurements under ultra-strong pulsed magnetic fields. These findings promise an efficient way to significantly improve the performance and extend the application of optical measurements under pulsed high magnetic fields.