Dynamic nitrogen vacancy magnetometry by single-shot optical streaking microscopy

Nitrogen vacancy diamonds have emerged as sensitive solid-state magnetic field sensors capable of producing diffraction limited and sub-diffraction field images.Here,for the first time,to our knowledge,we extend those measurements to high-speed imaging,which can be readily applied to analyze currents and magnetic field dynamics in circuits on a microscopic scale.To overcome detector acquisition rate limitations,we designed an optical streaking nitrogen vacancy microscope to acquire two-dimensional spatiotemporal kymograms.We demonstrate magnetic field wave imaging with micro-scale spatial extent and~400μs temporal resolution.In validating this system,we detected magnetic fields down to 10μT for 40 Hz magnetic fields using single-shot imaging and captured the spatial transit of an electromagnetic needle at streak rates as high as 110μm/ms.This design has the capability to be readily extended to full 3D video acquisition by utilizing compressed sensing techniques and a potential for further improvement of spatial resolution,acquisition speed,and sensitivity.The device opens opportunities to many potential applications where transient magnetic events can be isolated to a single spatial axis,such as acquiring spatially propagating action potentials for brain imaging and remotely interrogating integrated circuits.

Synergistic effect of picosecond optical and nanosecond electrical pulses on dielectric breakdown in aqueous solutions

The combined effect of short(picosecond) optical and(nanosecond) electrical pulses on dielectric breakdown is investigated both theoretically and experimentally. It was demonstrated that nanosecond electrical pulses(nsEPs),being applied simultaneously with picosecond optical pulses, reduce the threshold for optical breakdown.Experimental results are discussed with respect to an extended model for opto-electrical-induced breakdown.The newly unveiled effect is expected to play a significant role in spatially confined electroporation and further advances in laser-ablation-based processes while also allowing for measurements of ambipolar diffusion constants.