Figure 3: Controlling the length scale of nuclear magnetism with illumination wavelength.
From: Optically rewritable patterns of nuclear magnetization in gallium arsenide
Stray field images of nuclear polarization for 69Ga as a function of irradiation wavelength for an illumination intensity of 37 mW cm−2 after 10 min. (i) 810 nm, (ii) 820 nm, (iii) 825 nm, (iv) 830 nm, (v) 835 nm, (vi) 855 nm. Red curves correspond to σ+ helicity and black curves correspond to σ−. Decreasing the wavelength to 810 nm (i) provides the shortest length scale for polarization patterning. Our analysis indicates that the width of the negative polarization region associated with this spectrum is ~40 μm.
