Browsing by Author "El-Ghayoury, Abdelkrim"

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All-Optical Switching and Two-States Light-Controlled Coherent-Incoherent Random Lasing in a Thiophene-Based Donor-Acceptor System
(2018-07-05)
Szukalski, Adam
;
Ayadi, Awatef
;
Haupa, Karolina
;
El-Ghayoury, Abdelkrim
;
Sahraoui, Bouchta
We describe herein the synthesis and characterization of a thiophene-based donor-acceptor system, namely (E)-2-(4-nitrostyryl)-5-phenylthiophene (Th-pNO(2)), which was prepared under Horner-Wadsworth-Emmons conditions. The UV/Vis absorption bands, including the intramolecular charge transfer (ICT) band, were fully assigned using DFT and TD-DFT computations. The results of both efficient third-order nonlinear optical properties and light-amplification phenomena are presented. Investigations of photoinduced birefringence (PIB) in optical Kerr effect (OKE) experiments showed a great potential for this particular compound as an efficient, fully reversible, and fast optical switch. Time constants for the observed trans-cis-trans molecular transitions are in the range of microseconds and give a competitive experimental result for the well-known and exploited azobenzene derivatives. Random lasing (RL) investigations confirmed that this organic system is potentially useful to achieve strong light enhancement, observed as a multimode lasing action. Both RL and OKE measurements indicate that this material is a representative of thiophene derivatives, which can be utilized to fabricate fast all-optical switches or random lasers (light amplifiers).
TTF based donor-pi-acceptor dyads synthesized for NLO applications
(2017-03)
Ayadi, Awatef
;
Szukalski, Adam
;
El-Ghayoury, Abdelkrim
;
Haupa, Karolina
;
Zouari, Nabil
Two new TTF-pi-acceptor dyads that contain p-nitrophenyl group as acceptor and bis-(styryl)benzene system as an efficient pi-conjugated bridge have been synthesized by multistep synthetic procedure and their electrochemical behavior has been studied by cyclic voltammetry (CV). The occurrence of an intramolecular charge transfer (ICT) in these molecules has been evidenced by UV-Visible electronic absorption spectroscopy and these studies were completed by DFT calculations in both gas phase and in solution. The nonlinear optical parameters obtained via SHG and THG measurements are described and indicate that these materials are valuable candidates for the construction of optoelectronic and photonic devices. The Optical Kerr Effect measurements indicate that these materials exhibit a great potential in the field of optical switchers construction, where the material\'s photoresponse time is a crucial parameter. (C) 2016 Elsevier Ltd. All rights reserved.