Sixth Harmonic of A Nd:YVO₄ Laser Generation In KBBF for ARPES

We report that a deep ultraviolet (DUV) laser from the sixth harmonic of a 1064nm laser has been firstly used as light source in an ultrahigh energy-resolution angle-resolved photoemission spectroscopy (ARPES). The wavelength is 177.3nm obtained by using the second harmonic KBe₂BO₃F₂
crystal with a frequency tripled 1064nm Nd:YVO₄ laser. The large flux (10¹⁴-10¹⁵photons/s) and narrow line width (0.26meV) are suitable for the ultrahigh-energy resolution ARPES. The laser-ARPES can be a powerful tool to study the electronic structure at and near the Fermi level of the superconductor and correlated materials. The laser-ARPES has worked more than 500h already.