Fig. 1
From: All-optical control of long-lived nuclear spins in rare-earth doped nanoparticles
All-optical nuclear spin coherence investigation in 151Eu3+-doped Y2O3 nanoparticles. a 151Eu3+ ground-state hyperfine structure in Y2O3. Two-color laser pulses (at ω1 and ω2 frequencies) resonant with the 7F0→5D0 transition at 580.883 nm create coherent states between the \(\pm \left| {1{\mathrm{/}}2}\rangle \right.\) and \(\pm \left| {3{\mathrm{/}}2}\rangle \right.\) nuclear spin levels. \(\pm \left| {{\mathrm{exc}}}\rangle \right.\) represents the excited state hyperfine levels. b Optical transmission spectrum after optical pumping. Ground-state population initialization to \(\pm \left| {1{\mathrm{/}}2}\rangle \right.\) corresponds to a lower transmission at ω1. High transmission (~95%) at 0 (ω2) and 33.99 MHz (ω3) evidences efficient population depletion in the \(\pm \left| {3{\mathrm{/}}2}\rangle \right.\) and \(\pm \left| {5{\mathrm{/}}2}\rangle \right.\) levels. ωopt = 516.098 THz (580.883 nm). c All-optical spin-echo sequence with heterodyne detection. Each sequence is preceded by optical pumping and followed by chirped pulses to reset the spin population to equilibrium. d Fast Fourier transform of the heterodyne signal revealing the spin echo at 29.34 MHz
