We implement time-resolved Kerr microscopy (TRKM) system with ∼1μm spatial resolution for observation of coupled electronnuclear spin dynamics such as dynamic nuclear polarization (DNP) in a local area of the laser spot. From TRKM measurements, Larmor precession of electron spins injected by right (σ) or left (σ-) circular polarized pump pulse is detected. The difference of the precession frequencies between σ and σ- pumping corresponds to the polarization-dependent nuclear magnetic field caused by DNP. This indicates that we successfully detect coupled electronnuclear spin dynamics in a local area of the laser spot size of ∼1.5×1.5μm2. Furthermore, we show the pump and probe power dependences of DNP in high optical intensity region. All-optical NMR is also demonstrated at arbitrary frequencies by controlling acousto-optical modulator.
|Number of pages
|Physica E: Low-Dimensional Systems and Nanostructures
|Published - 2010 Sept