Green, B.L.B.L.GreenBreeze, B.G.B.G.BreezeRees, G.J.G.J.ReesHanna, J.V.J.V.HannaJYH PIN CHOUIvády, V.V.IvádyGali, A.A.GaliNewton, M.E.M.E.Newton2024-09-182024-09-182017https://www.scopus.com/record/display.uri?eid=2-s2.0-85028770674&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/721380Article number 054101Low thermal polarization of nuclear spins is a primary sensitivity limitation for nuclear magnetic resonance. Here we demonstrate optically pumped (microwave-free) nuclear spin polarization of C13 and N15 in N15-doped diamond. N15 polarization enhancements up to -2000 above thermal equilibrium are observed in the paramagnetic system Ns0. Nuclear spin polarization is shown to diffuse to bulk C13 with NMR enhancements of -200 at room temperature and -500 at 240 K, enabling a route to microwave-free high-sensitivity NMR study of biological samples in ambient conditions. © 2017 American Physical Society.journal article10.1103/PhysRevB.96.0541012-s2.0-85028770674