Spectral profiles of two-photon absorption: Coherent versus two-step two-photon absorption

2004 ◽  
Vol 846 ◽  
Author(s):  
S. Polyutov ◽  
I. Minkov ◽  
F. Gel'mukhanov ◽  
K. Kamada ◽  
A. Baev ◽  
...  

ABSTRACTWe present a theory of two-photon absorption in solutions which addresses the formation of spectral shapes taking account of the vibrational degrees of freedom. The theory is used to rationalize observed differences between spectral shapes of one- and two-photon absorption. We elaborate on two underlying causes, one trivial and one non-trivial, behind these differences. The first refers simply to the fact that the set of excited electronic states constituting the spectra will have different relative cross sections for one-and two- photon absorption. The second reason is that the two-step and coherent two-photon absorption processes are competing, making the one-and two-photon spectral bands different even considering a single final state. The theory is applied to the N-101 molecule [di-phenyl-amino-nitro-stilbene] which was recently studied experimentally in the paper [ T.-C. Lin, G.S. He, P.N. Prasad, and L.-S. Tan, J. Mater. Chem., 14, 982, 2004.]

2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.


2006 ◽  
Vol 84 (9) ◽  
pp. 1114-1123 ◽  
Author(s):  
Xiang-Biao Zhang ◽  
Ji-Kang Feng ◽  
Ai-Min Ren ◽  
Chia-Chung Sun

The electronic structures and the one- and two-photon absorption (TPA) properties of two series of the olefin-linked paracyclophane (pCp) oligomers have been studied using AM1 and ZINDO-SOS methods. The relationship between the TPA cross sections and the molecular chain length is obtained. The maximum TPA cross section increases in proportion to Nα (N denotes the number of repeat units) and the values of α depend on different molecular structures. The olefin-linked pCp oligomers, which have good transparency and large TPA cross sections, are promising candidates for TPA materials.Key words: two-photon properties, paracyclophane oligomer, AM1, ZINDO-SOS.


2006 ◽  
Vol 05 (03) ◽  
pp. 535-542 ◽  
Author(s):  
SHU-LAN ZHOU ◽  
XIAN ZHAO ◽  
XUE-QIN SUN ◽  
XIU-FENG CHENG

In order to investigate the substituting effects on the two-photon absorption (TPA) cross-section and the position of the TPA peak, the one- and two-photon absorption properties of a series of symmetric molecules with bis(stilbene)diethylene π-conjugated bridge have been studied using ZINDO-SOS method. The transition moments from the ground state to the lowest excited state (M0k) and from the lowest excited state to the TPA final state (Mkn), together with the detuning energy ΔE = E0k - Ekn/2, were calculated using the INDO1 method included in the ZINDO program. The results indicate that bis-donor and bis-acceptor substitutions mainly affect the transition dipole moments M0k and Mkn, and that donor or acceptor side groups have a strong influence on the detuning energy. Meanwhile, it was found that the molecules with the bis-donor structure possess enhanced TPA cross sections, and the molecules with cyano or methoxy side groups have a large red-shift with respect to molecules without side groups.


2009 ◽  
Vol 27 (7) ◽  
pp. 1269-1279 ◽  
Author(s):  
Wenchao LI ◽  
Jikang FENG ◽  
Aimin REN ◽  
Xiangbiao ZHANG ◽  
Chiachung SUN

2006 ◽  
Vol 12 (8) ◽  
pp. 2303-2317 ◽  
Author(s):  
Shin-ichiro Kato ◽  
Taisuke Matsumoto ◽  
Motoyuki Shigeiwa ◽  
Hideki Gorohmaru ◽  
Shuuichi Maeda ◽  
...  

2018 ◽  
Vol 42 (17) ◽  
pp. 14325-14331 ◽  
Author(s):  
Ruiqing Feng ◽  
Longlong Li ◽  
Bing Li ◽  
Jinhui Li ◽  
Dan Peng ◽  
...  

DMI could light up the RNA of the nucleus and the cytoplasm in living systems, which not only exhibits larger two-photon absorption cross-sections (981 GM), but also displays high-permeability to plasma membranes of vigorous cells.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Wang ◽  
Huang Wu ◽  
Penghao Li ◽  
Su Chen ◽  
Leighton O. Jones ◽  
...  

Abstract Two-photon excited near-infrared fluorescence materials have garnered considerable attention because of their superior optical penetration, higher spatial resolution, and lower optical scattering compared with other optical materials. Herein, a convenient and efficient supramolecular approach is used to synthesize a two-photon excited near-infrared emissive co-crystalline material. A naphthalenediimide-based triangular macrocycle and coronene form selectively two co-crystals. The triangle-shaped co-crystal emits deep-red fluorescence, while the quadrangle-shaped co-crystal displays deep-red and near-infrared emission centered on 668 nm, which represents a 162 nm red-shift compared with its precursors. Benefiting from intermolecular charge transfer interactions, the two co-crystals possess higher calculated two-photon absorption cross-sections than those of their individual constituents. Their two-photon absorption bands reach into the NIR-II region of the electromagnetic spectrum. The quadrangle-shaped co-crystal constitutes a unique material that exhibits two-photon absorption and near-infrared emission simultaneously. This co-crystallization strategy holds considerable promise for the future design and synthesis of more advanced optical materials.


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