polythiophenes are of considerable interest as synthetic metals. the optical properties of polythiophenes can be easily affected by alkyl chain or other side groups to the thiophene ring. the effect of polymerization degree on the energy gap was studied in the case of polythiophene as a conjugated polymer at b3lyp/6-31+g(3d,3p) level of theory. up to n = 16 could be confident that this degree o...

In this study, the nonlinear optical properties and optical limiting performance of the silver nanoparticles (AgNPs) in distilled water are investigated. The nonlinear absorption coefficient of the colloid is measured by the Z-scan technique. The optical limiting behavior of the AgNP suspension is investigated under exposure to nanosecond laser pulses at 532 nm. The results show that nonlinear ...

This paper deals with the design and simulation of all-optical 4×2 encoderusing the wave interference effect in photonic crystals. By producing 4 opticalwaveguides as input and two waveguides as output, the given structure was designed.The size of the designed structure is 133.9 μm2. The given all-optical encoder has acontrast ratio of 13.2 dB, the response time of 0.45 ...

purpose: to evaluate the rate of optical coherence tomography (oct) grid decentration in a routine practice and its effect on thickness measurements methods: topcon spectral domain oct scans from various macular diseases including age related macular degeneration, diabetic macular edema, macular pucker and central serous chorioretinopathy (cscr) were studied in all patients visited during seven...

this study was conducted to define the prevalence and types of corneal astigmatism in relation with corneal optical power, axial length, sex and patient age. 641 cataract patients were included in a descriptive study. complete eye examinations were included in a descriptive study. complete eye examinations were performed. the data were analysed by standard procedures including analysis of varia...

conclusions the psychotic symptoms due to temporal lobe epilepsy can be resolved with lamotrigine administration. introduction visual illusions and hallucinations may accompany a wide variety of disorders with many various etiologies; therefore, they are nonspecific phenomena. in a partial seizure, a localized hyper synchronous neuronal discharge evolving into a partial seizure affecting a part...

this study was conducted to determine the use of three-dimensional ultrasonography (3du) in ocular imaging of the dog and measuring of its optical axis. 12 healthy mixed-breed dogs including 6 males and 6 females were studied. 3du of the eyes were done using a 5–12 mhz linear trapezoid transducer. 3du of the eyes were evaluated and the normal optical long axis through a line between the cornea ...

this review reports recent advances in the field of polymer–layered silicate nano composites. thesematerials have attracted both academic and industrial attention because they exhibit dramaticimprovement in properties at very low filler contents. herein, the structure, preparation andproperties of polymer–layered silicate nanocomposites are discussed in general, and finally the effectof clay na...

in this paper first we try to analysis the behavior ofthe soas in the optical networks and then have proposed anumerical simple model to simulate the behavior of thesemiconductor optical amplifiers. after that by employing thismodel as inline amplifier for a dwdm optical system, we havesimulated the transmission of 10 channels with bit rate 10 gb/sup to distance 3970 km with rz-dpsk modulation ...