https://doi.org/10.1140/epjd/s10053-021-00116-5
Regular Article - Optical Phenomena and Photonics
Excited state absorption of Cu-doped barium borate nanostructures under nanopulsed laser excitation
1
Nanophotonics Laboratory, School of Physics, Bharathidasan University, 620 024, Tiruchirappalli, India
2
Department of Chemistry, King Khalid University, P.O. Box 9004, 61413, Abha, Saudi Arabia
Received:
18
December
2020
Accepted:
25
February
2021
Published online:
17
March
2021
Intensity- and concentration-dependent nonlinear absorption of Cu-doped (
and 
-
nanostructures was measured by a standard open aperture Z-scan setup under nanopulsed (9 ns, 10 Hz) laser excitation (532 nm) at various peak intensities (1.26–2.52 GW/
. Intensity-dependent 2PA coefficient exposes the involvement of accumulative 2PA process rather than genuine 2PA. From ground state absorption studies, existence of new energy states due to Cu incorporation has availed a near-resonant state favoring excited state absorption leading to sequential 2PA. Among the samples, 0.05 M Cu-doped -
m/W, 
and 0.03 M Cu-doped 
-
m/W, 
exhibit higher 2PA coefficient and lower onset limiting threshold. The presence of CT and intragap states of 
ions-induced strain in visible region transformed genuine 2PA in pristine ( and - nanorods into sequential 2PA (1PA
2PA) in Cu-doped ( and -. By simple hydrothermal process, concentration-dependent Cu-doped ( and - nanostructures were prepared and their structural and optical properties were studied. Thus, Cu-doped ( and - exhibit sequential 2PA (1PAESA)-based optical limiting with enhanced 2PA coefficient than its pristine ( and - nanorods.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021
