Tip-enhanced near-field optical images and correlated topographic images of an organic semiconductor film (diindenoperylene, DIP) on Si have been recorded with high optical contrast and high spatial resolution (17 nm) using a parabolic mirror with a high numerical aperture for tip illumination and signal collection. The DIP molecular domain boundaries being one to four molecular layers (1.5-6 n...

Novel materials suitable for optoelectronics are of great interest due to limited and diminishing energy resources and the movement toward a green earth. We report a simple film growth method to tune the S composition, x from 1 to 2 in semiconductor ultrathin SnSx films on quartz substrates, that is, single phase SnS, single phase SnS2, and mixed phases of both SnS and SnS2 by varying the sulfu...

A novel approach to chemical application of long period grating (LPG) optical fibers was demonstrated, which were modified with a film nanoassembled by the alternate deposition of SiO(2) nanoparticles (SiO(2) NPs) and poly(diallyldimethyl ammonium chloride) (PDDA). Nanopores of the sensor film could be used for sensitive adsorption of chemical species in water, which induced the changes in the ...

Residual stress in optical thin film coatings can cause adhesion failures, cracking, buckling, and bending of the substrates. The stress in the coating depends on the materials used, deposition process, and the design. The bulk properties of the coating materials and the substrate such as thermal coefficient of expansion, Young’s Modulus, Poisson’s Ratio, etc., are basic parameters to be consid...

A theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. The calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...

Nanocrystalline cadmium sulfide thin films as antireflection materials for solar cells have been prepared by a new chemical solution deposition route in an aqueous medium at 50 °C. as-deposited thin films were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and optical absorption spectra. X-ray diffraction data indicated the formation of hexagonal na...

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their stru...

A thin film of electron-trapping material (ETM), when combined with suitable optical bistability, is considered as medium for optical implementation of bio-inspired neural nets. The optical mechanism of ETM under blue light and NIR exposure has the inherent ability at the material level to mimic the crucial components of the stylized Hodgkin-Huxley model of biological neuron. Combining this uni...