Excited state absorption of Cu-doped barium borate nanostructures under nanopulsed laser excitation C. Babeela, Mohammed A. Assiri, Abdullah G. Al-Sehemi, Mehboobali Pannipara and T. C. Sabari Girisun Eur. Phys. J. D, 75 3 (2021) 102 Published online: 17 March 2021 DOI: 10.1140/epjd/s10053-021-00116-5