Single-Frequency 389-nm Coherent Light by Efficient Wavelength Conversion for Magnetic Resonance Imaging of Porous Materials with Nuclear Spin Polarization of 3He Atoms

摘要

We report that we developed the efficient 389-nm cw coherent light, corresponding to the optical transition of 23S1→33PJ, for optical-pumping the metastable 3He atoms by means of the high finesse external cavity with BiBO crystal. We obtained the second harmonic power of 380mW with the maximum conversion efficiency of 56%. To the best of our knowledge, it is the most efficient frequency-doubling based on BiBO crystal recently reached at around 390 nm. In addition, the out-put power was stable enough to scan the frequency and to perform the spectroscopy.