Study of the Chemical Vapor Deposition of Nano-Sized Carbon Phases on {001} Silicon.

Different nano-sized phases were synthesized using chemical vapor deposition (CVD) processes. The deposition took place on {001} Si substrates at about 1150-1160 °C. The carbon source was thermally decomposed acetone (CH)CO in a main gas flow of argon.

Novel Approach for Synthesis of Graphene-like Phases by Pulsed Laser Ablation in a Flow-Mode Suspension.

The present study investigates the possibility of obtaining graphene-like phases (defected graphene, graphene oxide, and reduced graphene oxide) as fine suspensions by applying a novel pulsed laser ablation (PLA) approach in flow mode. Two types of suspensions of microcrystalline graphite in aqueous suspensions and two types of microcrystalline graphite in suspensions of 6% hydrogen peroxide solution were irradiated in a quartz tube through which they flow. The third (λ = 355 nm) and fourth harmonics (λ = 266 nm) of an Nd:YAG laser system (15 ns pulse duration and 10 Hz pulse repetition rate) were used.

Silver Flowerlike Structures for Surface-Enhanced Raman Spectroscopy.

Micro- and nanoflowers are a class of materials composed of particles with high surface-to-volume ratio. They have been extensively studied in the last decade due to simple preparation protocols and promising applications in biosensing, as drug delivery agents, for water purification, and so on. Flowerlike objects, due to their highly irregular surface, may act also as plasmonic materials, providing resonant coupling between optical waves and surface plasmon excitations.

Note: Simple vacuum feedthrough for optical fiber with SubMiniature version A connectors at both ends.

We present a simple way to insert an optical fiber, with existing standard SubMiniature version A connectors on both ends into a vacuum system. The fitting is tested in scanning electron microscope, at working pressures down to 2 × 10(-5) mbar for cathodoluminescent measurements. With slight modifications this fitting could be successfully adapted for optical fiber insertion into pressurized systems.

Variable distance absolute reflectometry.

In many interferometric applications the variation of the reflected light intensity due to the separation distance change between two optical systems is the raw signal from which some unknown parameters must be determined. We consider the general situation in which the signal offset and amplification, the initial separation, and the optical properties of one of the systems are unknown. Using some major results from the complex analysis we derive closed-form expressions that give the exact solution of the above inverse problem in terms of the signal's Fourier coefficients.

Plasmon-enhanced sub-wavelength laser ablation: plasmonic nanojets.

In response to the incident light's electric field, the electron density oscillates in the plasmonic hotspots producing an electric current. Associated Ohmic losses raise the temperature of the material within the plasmonic hotspot above the melting point. A nanojet and nanosphere ejection can then be observed precisely from the plasmonic hotspots.

Instrument and methods for surface dilatational rheology measurements.

We describe an instrument combining the advantages of two methods, axisymmetric drop shape analysis for well-deformed drops and capillary pressure tensiometry for spherical drops, both used for measuring the interfacial tension and interfacial rheological parameters. The rheological parameters are the complex interfacial elasticity, and the surface elasticity and viscosity of Kelvin-Voigt and Maxwell rheological models. The instrument is applicable for investigation of the effect of different types of surfactants (nonionic, ionic, proteins, and polymers) on the interfacial rheological properties both of air/water and oil/water interfaces, and of interfaces between liquids with equal mass densities.

Standards for Which the Ellipsometric Parameter psi Remains Insensitive to Variations in the Angle of Incidence.

We examine the possibility of using two- and three-phase systems suitable as standards for which the ellipsometric parameter ? remains insensitive to variations in the angle of incidence. These standards avoid propagation of errors in the angle of incidence with respect to the measured standard ? value. Different materials (dielectrics, metals, and semiconductors), adequate for the above purpose, are considered in different structure combinations, and their optical response are analyzed.

An electron beam lithography and digital image acquisition system for scanning electron microscopes.

A low-cost microcontroller based control and data acquisition unit for digital image recording of scanning electron microscope (SEM) images and scanning electron microscope based electron beam lithography (EBL) is described. The developed microcontroller low-level embedded software incorporates major time critical functions for image acquisition and electron beam lithography and makes the unit an intelligent module which communicates via USB with the main computer. The system allows recording of images with up to 4096 x 4096 pixel size, different scan modes, controllable dwell time, synchronization with main power frequency, and other user controllable functions.

Correction for nonlinearity and polarization-dependent sensitivity in the detection system of rotating analyzer ellipsometers.

Systematic errors due to nonlinearity and polarization-dependent sensitivity in the detection system of rotating analyzer ellipsometers are described. Post Fourier analysis procedures for detection and correction of these effects are presented.