We investigate the bulk superconducting electronic structure in optimally doped YBa2Cu3O7-δ (YBCO) using laser-excited angle-resolved photoemission spectroscopy. The band dispersions with the dx2-y2-wave like gap opening are observed without being hindered by surface state and CuO chain band due to bulk-sensitivity and/or matrix element effect at hν=6.994eV. The momentum-dependence of the superconducting gap exhibits a nonzero minimum of ∼12 meV along the (0,0)-(π,π) line. In addition, the unusual suppression of the quasiparticle coherence is observed at T/Tc>0.5-0.7.
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