Open AccessParticle size-dependent giant nonlinear absorption in nanostructured Ni-Ti alloys
Author(s) -
John Kiran Anthony,
Hee Cheoul Kim,
Hwang Woon Lee,
Santosh Kumar Mahapatra,
Hae Min Lee,
Chang Koo Kim,
Kihong Kim,
H. Lim,
Fabıan Rotermund
Publication year - 2008
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.011193
Subject(s) - saturable absorption , materials science , absorption (acoustics) , attenuation coefficient , two photon absorption , analytical chemistry (journal) , laser , free carrier absorption , excited state , molecular physics , optics , optoelectronics , atomic physics , silicon , fiber laser , chemistry , wavelength , physics , chromatography , composite material
The nonlinear absorption in nanostructured Ni-Ti alloys, fabricated by electrochemical deposition, was investigated at 532 and 1064 nm. The type of nonlinear absorption (saturable or reverse saturable absorption) was observed to depend on the laser intensity as well as on the nanoparticle size. The nanostructured Ni-Ti alloys comprising particle mean diameters of 20 and 30 nm exhibited large three-photon absorption (3PA coefficient approximately 10(6) cm(3)/GW(2)) and large two-photon absorption (2PA coefficient approximately 10(5) cm/GW) at 532 nm, respectively. The observed change over from reverse saturable absorption to saturable absorption at high peak intensities has qualitatively been analyzed by the excited-state theory of conduction electrons.