Nonlinear optical device

SAMs are generating attention for numerous potential uses ranging from chromatography [SO] to substrates for liquid crystal alignment [SI]. Most attention has been focused on future application as nonlinear optical devices [49] however, their use to control electron transfer at electrochemical surfaces has already been realized [S2], In addition, they provide ideal model surfaces for studies of protein adsorption [S3]. 

Another approach is to use the LB film as a template to limit the size of growing colloids such as the Q-state semiconductors that have applications in nonlinear optical devices. Furlong and co-workers have successfully synthesized CdSe [186] and CdS [187] nanoparticles (<5 nm in radius) in Cd arachidate LB films. Finally, as a low-temperature ceramic process, LB films can be converted to oxide layers by UV and ozone treatment examples are polydimethylsiloxane films to make SiO [188] and Cd arachidate to make CdOjt [189]. 

Nonlinear Optical Devices. A transparent, optically active, sol—gel-derived organic—inorganic glass has been synthesized (68). This hybrid consists of a 2,4-dinitroaminophenylpropyl-triethoxysilane covalently bound to a siUcon alkoxide-derived siUca network. This hybrid exhibits a strong electric field-induced second harmonic signal and showed no signs of crystallization. 

Photonics Nonlinear Optical Devices and Perspective," MRS Bull XIII, No. 8 (1988). 

Thin polymeric films have important industrial apphcations (e.g., as protective coatings, lubricants, adhesives, dielectric or nonlinear optic devices, etc.) and pose many fundamental problems of film stability [1,2,4]. An important question, therefore, is whether these films break up and spontaneously dewett the substrate, resulting in the formation of droplets. The... 

One dimensional conjugated carbon polymers can occur in many configurations as depicted in Figure 2 where also we included some chains with nitrogen and sulfur for later reference. Also included there are inorganic one dimensional semiconductors, like SbSI and SbSBr for later comparison. Besides the depicted one-dimensional system others like TCNQ- and KCP-salts could be included here as well but rough measurements of their nonlinear coefficients gave deceptively small values which combined with their ill-characterisation make them poor candidates for nonlinear optical devices. 

The above conclusions introduce intrinsic limitations to the use of the ID conjugated systems in nonlinear optical devices. Although these may benefit (38) from the high nonlinearities,their response speed will be limited by the motion of such defects. These may also be formed by other means than light and this will clearly have implications on photoelastic, pyroelectric and piezoelectric effects as well. We point out that materials like polydiacetylenes may show appreciable quadrupolar pyroelectric effect (39). 

The linear and nonlinear optical properties of one-dimensional conjugated polymers contain a wealth of information closely related to the structure and dynamics of the ir-electron distribution and to their interaction with the lattice distorsions. The existing values of the nonlinear susceptibilities indicate that these materials are strong candidates for nonlinear optical devices in different applications. However their time response may be limited by the diffusion time of intrinsic conjugation defects and the electron-phonon coupling. Since these defects arise from competition of resonant chemical structures the possible remedy is to control this competition without affecting the delocalization. The understanding of the polymerisation process is consequently essential. 

U. Schoberl, J. Salbeck, and J. Daub, Precursor compounds for organic metals and nonlinear optical devices from carbohydrate-derived hydroxymethylfurfuraldehyde Furanoid electron donors and push/pull substituted compounds, Adv. Mater., 4 (1992) 41-44. 

Since S(Eo) is a nonlinear function, new frequencies are created. The source therefore emits an optical field Ei, with frequencies not present in the original wave E0. This leads to numerous interesting phenomena that have been utilized to make useful nonlinear-optics devices. 

Brunei M, Ozkul C, Sanchez F. Nonlinear optical devices for oxygen concentration measurements. Sens Actuators 2000 B62 238 13. 

The potential development of optoelectronic devices based on nonlinear polarization of the MMCT transitions of mixed-valence complexes has been the subject of an investigation 100). The hyperpolarizabilities measured for the complexes [(CN)5Ru(jU.-CN)Ru(NH3)5] and [(T75-C5H5)Ru(PPh3)2( U-CN)Ru(NH3)5]3+ are among the largest known for a solution species. The tunability of MMCT energy is an added advantage for the construction of nonlinear optical devices. 

Jen [2] prepared thermally reversibly electrooptic polymers, (V), via a Diels-Alder reaction, as illustrated below, that were used in second-order nonlinear optical devices. 

Two of the advantages of using such materials are flexibility in the fabrication of optical structures and the tailoring of optical properties through material engineering. For application in guided-wave nonlinear optical devices high optical quality and low dielectric constant are but two of the requisite properties. 

Essentially, a small part of the laser pulse train that is ultimately used to trigger the photocathode is split off to create a synchronized laser probe pulse train. The probe line is equipped with different nonlinear optical devices that permit the tunability of the probe beam from the near UV to the NIR. Available probe sources include the laser fundamental (790 nm) and second harmonic (395 nm), a white-light continuum (470-750 nm) generated in a sapphire plate, and a continuously tunable Optical Parametric Amplifier (470-750 nm, 1000-1600 nm, and 240-375 nm by SHG), able to deliver light pulses shorter than 30 fs after compression. 

Molecules are suitable for nonlinear optics devices, only if they satisfy several requirements [35]. Amongst others are demands, due to the high temperatures needed... 

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