Nonlinear Organic Molecules and Materials for Optoelectronic Devices

Abstract

The development of important applications related to optical telecommunications and optical signal processing rely increasingly on nonlinear optical phenomena underlying these optical functions such as frequency conversion and modulation, amplification and emission, multiplexing and directional switching, optical logical gates, and others. This will depend on the design, elaboration and availability of new materials displaying enhanced nonlinearities to be subsequently integrated into waveguiding devices. Organic materials are noteworthy candidates in this context, provided their microscopic and macroscopic properties are properly optimized with respect to the type of application required. Among the key-factors in the development of these materials are the quasi-unlimited variety of molecular structures accessible by organic synthesis, the possibility to connect specific nonlinear properties to other kinds of functionalities which are of crucial importance for the development of commercial devices (e.g., compatibility with other materials used in integrated optical circuits such as semi-conductors), and their exceptionally large second-order, non-resonant nonlinear response. Such performances are strongly dependent on a better understanding of the ‘molecular engineering’, rules, correlating molecular structures to their nonlinear optical properties towards optimization of the microscopic second order polarizabilities β and third-order polarizabilities γ. We will present in the following some examples of the most recent developments of highly efficient nonlinear molecules, ranging from purely one-dimensional structures such as polyenes to fully three-dimensional systems, taking full advantage of the tensorial character of the microscopic or macroscopic susceptibility tensors.

Excited-State Structure of Oligothiophene Dendrimers: Computational and Experimental Study

“…2,4-12 Consequently, organic dendrimers have been actively investigated as new artificial light harvesting and solar energy conversion devices, [13][14][15][16][17][18][19][20][21][22][23][24][25] as promising materials for organic electronics, 2, [26][27][28][29][30][31][32] and nonlinear optical applications, such as 3D microfabrication, 33 multiphoton-microscopy, 34 optical power-limiting 35 and sensing, 36,37 and optical signal processing. [38][39][40] A detailed comprehensive review of properties of organic dendrimers and ap-plications of those in sensing, catalysis, molecular electronics, photonics, and nanomedicine can be found in ref 3. Theoretical investigations of the excited-state phenomena provide explicit information about the nature of charge transfer and the degree of excited-state delocalization in dendritic structures. However, owing to their molecular structure complexity and large sizes, ab initio computations of excitations in dendrimers are still rather challenging.…”

Crystal growth and impact a Bisthiourea on structural, optical, thermal and mechanical behavior of Potassium sulphato oxalate a novel semi organic nonlinear optical material

“…In current past, the nonlinear optical (NLO) materials have gained substantial attention because of their excellent properties for frequency doubling in laser applications consisting of wide transparency range, large laser damage threshold and high nonlinear coefficient. At some point of a previous couple of years, many researchers have tried to increase the number of latest NLO materials for the above applications [1,2]. Organic compounds possess a better degree of optical nonlinearity than inorganic compounds; however, they are thermally volatile.…”

Studies on optical, mechanical, dielectric properties of bisthiourea nickel bromide NLO single crystal

“…In the recent years, the search for nonlinear optical (NLO) materials find extensive interest among the researchers due to their significant impact on laser technology, fiber optic communication, optical modulation and optical data storage technology [1]. The synthesis of novel and efficient frequency conversion materials has resulted in the development of semi-organic materials, which possess large nonlinearity, high resistance to laser induced damage, low angular sensitivity and good mechanical stability [2][3][4]. Efficient nonlinear optical crystals are required for laser devices due to technological importance in the fields of optoelectronics, signal processing, instrumentation and optical communication [5,6].…”