Fig. 3: Performance characterization of the FIRE system.

a Dark count versus photon count of the measured Raman spectrum of DMSO. b Statistical analysis of dark noise and crosstalk. CTC, crosstalk count. c, Electrical profiles of 1 and 6 photons indicated in a with an FWHM of 4 ns. d Recorded Raman spectrum of pure DMSO within 100 ms. e, Raw data of 19 continuously recorded Raman spectra of DMSO within 19 µs, truncated from (a). f Verification of the shot-noise-limited sensitivity. Error bars: SD (n = 2500 measurements). g Comparison of the sensitivity between FIRE and a Horiba HR800. The O–H background from water was removed for both spectra.