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.

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.