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Photoinduced second harmonic generation studies on Tris(thiourea)copper(I) perchlorate Cu(SC(NH 2 ) 2 ) 3 (ClO 4 )
Author(s) -
Krishnakumar V.,
Kalyanaraman S.,
Piasecki M.,
Kityk I. V.,
Bragiel P.
Publication year - 2008
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2020
Subject(s) - second harmonic generation , perchlorate , monoclinic crystal system , raman spectroscopy , crystal (programming language) , chemistry , copper , thiourea , analytical chemistry (journal) , materials science , molecular physics , crystallography , ion , optics , laser , crystal structure , programming language , physics , organic chemistry , chromatography , computer science
We have established a possibility to obtain the photoinduced optical second harmonic generation in the initially centrosymmetric single crystals of tris(thiourea)copper(I) perchlorate crystallized in the monoclinic system with the space group P 2 1 / c . The second‐order susceptibility of the investigated crystal was measured by inducing the crystal by external laser field. The results obtained are interesting and discussed in detail. We have established that the optical second harmonic generation achieves its maximum (about 0.84 pm/V) at photoinducing power density about 1430 kW/cm 2 for the fundamental wavelength 1064 nm. The maximal output second harmonic generation (SHG) was achieved at an angle of about 35° between the pumping and fundamental power beam's polarizations. Such maximum may be a consequence of a competition between the so formed anharmonic photothermal expansions and the thermal destruction that occurred because of the heating of the crystal surfaces. Our independent verifications have shown that the photoinduced surfaces were heated up to 8–12° C. This may cause occurrence of photothermal relaxation processes. The output SHG exists only immediately after the act of photoinduction. The obtained dependences are caused by specific features of the Raman spectra of the investigated crystals. Copyright © 2008 John Wiley & Sons, Ltd.