Multiple-photon excitation of nitrogen vacancy centers in diamond

Abstract

We report the first observation of multi-photon photoluminescence excitation (PLE) below the resonant energies of nitrogen vacancy (NV) centers in diamond. The quadratic and cubic dependence of the integrated fluorescence intensity as a function of excitation power indicate a two-photon excitation pathway for the NV − charge state and a three-photon process involved for the neutral NV 0 charge state respectively. Comparing the total multi-photon energy with its single-photon equivalent, the PLE spectra follows the absorption spectrum of single photon excitation. We also observed that the efficiency of photoluminescence for different charge states, as well as the decay time constant, was dependent on the excitation wavelength and power. arXiv:1710.07539v2 [cond-mat.mtrl-sci]

Nanodiamonds enable adaptive-optics enhanced, super-resolution, two-photon excitation microscopy

“…Therefore, for repetition rates , 1=t NV À, as is the case here, we would expect the count rate to be proportional to the laser repetition rate. Ji et al [28] also shows that, even with the 650 nm long pass filter in our system, there can still be significant NV0 emission leaking into the NV − channel. Furthermore, with 1070 nm excitation there is a significant cross-section for NV0 excitation.…”

“…Ji et al . [28] also shows that, even with the 650 nm long pass filter in our system, there can still be significant NV0 emission leaking into the NV − channel. Furthermore, with 1070 nm excitation there is a significant cross-section for NV0 excitation.…”

“…Should the application require efficient NV − only excitation, then Ji et al . [28] suggests longer wavelength excitation (more than 1150 nm) will improve the emission from NV − .…”

“…There is also a better signal-to-noise ratio as the fluorescence is only generated at the excitation focus and not throughout the whole illumination cone, giving significant benefits in autofluorescent samples. It has recently been shown that NV centres in bulk diamond samples can fluoresce with TPE [27] and likewise for NV in fragments of diamond of sizes 10-100 μm [28]. Tuning the excitation wavelengths in a range from 1030 to 1310 nm allows preferential excitation of NV − or the neutral NV0 state.…”

Nanodiamonds enable adaptive-optics enhanced, super-resolution, two-photon excitation microscopy

“…There is also a better signal to noise ratio as the fluorescence is only generated at the excitation focus and not throughout the whole illumination cone, giving significant benefits in autofluorescent samples. It has recently been shown that NV centres in bulk diamond samples can fluoresce with TPE (27) and likewise for NV in fragments of diamond of sizes 10 -100 µm (28). Tuning the excitation wavelengths in a range from 1030 to 1310 nm allows preferential excitation of NV-or the neutral NV0 state.…”