Title:	Enhanced Ultrafast Nonlinear Optical Response in Ferrite Core/Shell Nanostructures with Excellent Optical Limiting Performance.
Authors:	Perumbilavil, Sreekanth Lopez-Ortega, Alberto Tiwari, Gaurav Kumar Nogues, Josep Endo, Tamio Philip, Reji
Issue Date:	Feb-2018
Publisher:	Wiley-VCH Verlag
Citation:	Small, 2018, Vol. 14, p 1701001
Abstract:	Nonlinear optical nanostructured materials are gaining increased interest as optical limiters for various applications, although many of them suffer from reduced efficiencies at high‐light fluences due to photoinduced deterioration. The nonlinear optical properties of ferrite core/shell nanoparticles showing their robustness for ultrafast optical limiting applications are reported. At 100 fs ultrashort laser pulses the effective two‐photon absorption (2PA) coefficient shows a nonmonotonic dependence on the shell thickness, with a maximum value obtained for thin shells. In view of the local electric field confinement, this indicates that core/shell is an advantageous morphology to improve the nonlinear optical parameters, exhibiting excellent optical limiting performance with effective 2PA coefficients in the range of 10−12 cm W−1 (100 fs excitation), and optical limiting threshold fluences in the range of 1.7 J cm−2. These values are comparable to or better than most of the recently reported optical limiting materials. The quality of the open aperture Z‐scan data recorded from repeat measurements at intensities as high as 35 TW cm−2, indicates their considerably high optical damage thresholds in a toluene dispersion, ensuring their robustness in practical applications. Thus, the high photostability combined with the remarkable nonlinear optical properties makes these nanoparticles excellent candidates for ultrafast optical limiting applications.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/6894
ISSN:	16136829 (online) 1613-6810
Alternative Location:	http://dx.doi.org/10.1002/smll.201701001
Copyright:	2018 Wiley-VCH GmbH & Co.
Appears in Collections:	Research Papers (LAMP)

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