Intensity dependent third order optical nonlinearity of zinc-tetraphenyl porphyrin ultrathin film in nano-second regime

The third order nonlinear optical properties of 5,10,15,20 Tetraphenyl 21H,23H-porphine zinc (II) (ZnTPP) thin films have been investigated by using single beam Z-scan technique with 6 ns laser pulse operating at 532 nm. The ultrathin films of ZnTPP with the thickness of the order of 120 nm were fab...

Full description

Saved in:
Bibliographic Details
Main Authors: Rajesh Kumar, P. C., Clavian, L. M., Anil Kumar, K. V., Narayana Rao, D., Shihab, N. K., Sanjeev, Ganesh
Format: Conference Proceeding
Language:English
Subjects:
Absorptivity
Atomic energy levels
Defocusing
Laser beams
Nonlinearity
Optical properties
Refractivity
Symmetry
Thin films
Visible spectrum
Zinc
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The third order nonlinear optical properties of 5,10,15,20 Tetraphenyl 21H,23H-porphine zinc (II) (ZnTPP) thin films have been investigated by using single beam Z-scan technique with 6 ns laser pulse operating at 532 nm. The ultrathin films of ZnTPP with the thickness of the order of 120 nm were fabricated by means thermal vacuum coating technique. The UV-Visible spectrum depicts signature absorption curve identifying the enhancement in the symmetry of the molecule from D2h symmetry to D4h, due to the presence of central Zn metal ion. The ZnTPP thin film is exhibiting reverse saturation absorption (RSA) and strong self-defocusing effect. The effective two photon nonlinear absorption coefficients (βeff) and nonlinear refractive index (n2) obtained at different input on-axis peak intensities (I0) are of the order of 10−6 to 10−5 m/W and 10−13 to 10−11 m2/W. The decrease in βeff with the increase in intensity indicates that the observed RSA is due to the excited state absorption (ESA) from T1 triplet state to higher triplet state (Tn).
ISSN:0094-243X
1551-7616
DOI:10.1063/1.5113168