Anti-Stokes excitation of solid-state quantum emitters for nanoscale thermometry

(C to E) PL spectra of the ZPL for nanodiamond GeV (C), SiV (D), and NV (E) centers under Stokes (blue) and anti-Stokes (ocher) excitation (the full PL spectrum under Stokes excitation is shown in the relative inset). For each measurement in (C) to (E), the powers of the Stokes and anti-Stokes excitation lasers are the same: PL intensities are normalized to unity for display purposes: The measured values for anti-Stokes to Stokes PL intensity ratios for GeV, SiV, and NV centers are I /I | = (8.4 ± 3.3) × 10−2, I /I | = (13.2 ± 1.1) × 10−2, and I /I | = (11.9 ± 2.8) × 10−5. We show that anti-Stokes excitation of selected diamond color centers is an efficient process, detectable by standard PL spectroscopy, and leverage this finding to demonstrate upconversion PL from a single isolated GeV defect.

Source: advances.sciencemag.org