1,720,973 research outputs found
Molecular roughness analysis of development resist by LER method
No full textIn this paper, line edge roughness (LER) analysis on top–down images acquired by means of a scanning electron microscope is here proposed as a powerful and non-invasive technique to map the molecular aggregate distribution in a chemically amplified resist: in particular the periodicity of the aggregates themselves is determined via power spectral density method (PSD). The roughness of two resist developers with different chemical composition will be compared on the base of 1D power spectral density function: in case of SEM acquisition, the profile to be analyzed is extracted from a top–down acquisition, while atomic force microscope (AFM) inspection of surface topography allows to calculate PSD along a user-defined line. The two approaches confirm a reduced surface roughness in case of development with smaller molecule
All-optical pattern recognition for digital real-time information processing
No full textTo recognize digital streams of digital data, all-optical and passive techniques able to discriminate optical bit words in real time are presented. Discrimination capability of different correlators, both in free space architectures and in delay lines structures, is theoretically and experimentally analyzed. Experimental performances in word recognition are shown in the case of a volume holographic correlator, in the case of a lithographic phase-only-filter correlator, and in the case of a novel coherent delay lines correlator operating at the wavelength 1550 nm and at the bit rate of 2.5 Gbit/s
Holographic RAM for Optical Fiber Communications
No full textA highly efficient holographic RAM operating at optical communication wavelengths is presented. It exploits a two-color technique by recording digital bytes at 488 nm and retrieving the same information at 1550 nm. A larger number of stored holograms can be easily achieved in small size crystals in order to develop a realistic device. Furthermore the stored volume holograms can be employed reversibly as a database for optical byte recognition, producing output parallel correlation peaks in accordance with the incoming information matched to the stored on
Roughness reduction in submicron waveguides by low-molecular weight development
No full textRoughness reduction of a submicron waveguide profile in chemically amplified negative resist is here performed by proper selection of an alkali-based developer, taking into account that its smaller molecules lead to smoother resist surface by altering the developing mechanism of aggregate extraction performed with standard quaternary ammonium hydroxide. Roughness is then analyzed by means of classical Atomic Force Microscope inspection; furthermore, a non-invasive line edge roughness analysis approach based on top-down scanning electron microscope acquisition gives comparable results, in terms of standard deviation and molecular aggregate periodicity
Competitiveness of Stationary Planar Low concentration photovoltaic Modules Using Silicon Cells: a focus on concentrating optics
No full textNew design for trackless LCPV Modules with low-aspect ratio for compatibility with standard panels
No full textWe introduce and experimentally demonstrate a novel design for trackless LCPV modules with low-aspect ratio for compatibility with standard PV panels. This solution, named Gondola, enables a reduction of the silicon usage by up to a factor three, while keeping an aspect ratio of less than 0.3. The wide angular acceptance of the concentrator is compatible with both seasonal and daily angular sunlight excursions, removes the need for any tracking systems, and achieve more than 80% yearly-averaged optical collection efficiency with respect to standard panels. The design can be also tuned to address different orientation in the installation, without impairing the optical performance of the concentrato
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