Multiple-photon excitation of nitrogen vacancy center in diamond

TL;DR

This paper demonstrates multi-photon excitation of nitrogen vacancy centers in diamond, revealing charge state-dependent pathways and efficiencies, advancing understanding of NV center photophysics.

Contribution

First observation of multi-photon photoluminescence excitation in NV centers, showing charge state-specific multi-photon processes and their dependence on excitation parameters.

Findings

Two-photon excitation for NV- charge state

Three-photon process for NV0 charge state

Photoluminescence efficiency depends on wavelength and power

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 NV0 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.