Fig. 2: Widefield quantum sensing with a high-speed streaming camera.

The employed nitrogen vacancy (NV) center quantum sensing protocols require an initialization laser pulse (green), a microwave (MW) pulse (blue) to control the NV spin state, and a second laser pulse to read out the spin-dependent photoluminescence (PL) of the NV (red), which is captured by a camera. a For a Rabi experiment, the NV center’s spin state is observed as a function of the MW pulse duration. For each MW pulse duration, the spin state-dependent PL, as well as one reference image for common mode noise rejection, are recorded and averaged N_s times. b Increasing the MW pulse duration leads to spatially resolved Rabi oscillations for each pixel. The π/2- and π-pulse durations, determined for each pixel, serve as important control parameters for the coherently averaged synchronized readout (CASR) sequence to detect nuclear magnetic resonance (NMR) signals. c Image of the π-pulse duration determined from the single pixel Rabi fits. The pixel corresponding to the dataset in (b) is marked with a blue dot. d Radiofrequency (RF) signals are detected stroboscopically using the CASR pulse sequence. CASR is based on blocks of MW pulses (blue) starting and ending with an π/2- and N trains of π-pulse coupling the NV centers to the detected RF field (yellow). After each sensing block, the NV-fluorescence is detected, requiring a time-resolved readout on a high-speed streaming camera. e Detection of an RF calibration signal. The recorded pixel-wise time domain data (inset: a snapshot of the time domain signal) is Fourier transformed and shows a signal at the aliased CASR frequency. f Image of the signal-to-noise ratio (SNR) of the single pixel analysis of the CASR data. The pixel corresponding to the dataset in (e) is marked with a blue star.