75 research outputs found
Spatially and polarization resolved plasmon mediated transmission through continuous metal films
The experimental demonstration and characterization is made of the
plasmon-mediated resonant transmission through an embedded undulated continuous
thin metal film under normal incidence. 1D undulations are shown to enable a
spatially resolved polarisation filtering whereas 2D undulations lead to
spatially resolved, polarization independent transmission. Whereas the needed
submicron microstructure lends itself in principle to CD-like low-cost mass
replication by means of injection moulding and embossing, the present paper
demonstrates the expected transmission effects on experimental models based on
metal-coated photoresist gratings. The spectral and angular dependence in the
neighbourhood of resonance are investigated and the question of the excess
losses exhibited by surface plasmons is discusse
Flying phase mask for the printing of long submicron-period stitchingless gratings
International audienceLong and stitchingless gratings are printed by means of a read/write head comprising a phase mask illuminated by an intensity modulated laser beam and a reference grating displacement sensor which dictates the modulation period real time. A nearly perfect grating copying is achieved by fixing the sensor grating scale and the written grating substrate on a long platform sliding under the read/write hea
Verification and application of multi-source focus quantification
International audienceThe concept of the multi-source focus correlation method was presented in 2015 [1, 2]. A more accurate understanding of real on-product focus can be obtained by gathering information from different sectors: design, scanner short loop monitoring, scanner leveling, on-product focus and topography. This work will show that chip topography can be predicted from reticle density and perimeter density data, including experimental proof.Different pixel sizes are used to perform the correlation in-line with the minimum resolution, correlation length of CMP effects and the spot size of the scanner level sensor.Potential applications of the topography determination will be evaluated, includingoptimizing scanner leveling by ignoring non-critical parts of the field, and without the need for time-consuming offline topography measurements
Optical security device for document protection using plasmon resonant transmission through a thin corrugated metallic film embedded in a plastic foil
The well known resonant or extraordinary transmission through an undulated metallic thin film embedded in a dielectric layer using the Plasmon modes excitation under normal incidence is industrially exploited for document protection applications. While the effect is very spectrally sensitive to the incidence angle in collinear incidence since it leads to a transmission peak separation in two peaks, it is very tolerant in conical incidence (incidence angle in the plan normal to the grating direction). This property is used to create color transmission effects by playing with the sample rotation in the two directions to enhance the contrast of such effect. Theoretical approach, modeling and experimental demonstration in the visible range on a flexible plastic foil are presented for a see-through window implemented in document security
Three-grating monolithic phase-mask for the single-order writing of large-period gratings
A new type of achromatic high-efficiency monolithic phase mask is presented. The mask comprises three submicron period diffraction gratings at a single substrate side that create a purely single spatial frequency interferogram of large period. The optical scheme is that of an integrated Mach-Zehnder interferometer where all light circulation functions are performed by diffraction gratings. The paper describes the operation principle of the phase mask, the fabrication process, and its utilization in a write-on-the-fly scheme for the writing of a long, 2 µm-period grating
Dynamic Interferometry Lithography on a TiO 2
International audienceSolar electricity is one of the most promising renewable energy resources. However, the ratio module's cost/energy produced remains a major issue for classical photovoltaic energy. Many technologies have been developed to solve this problem, by using micro-or nanostructuring on the solar cell or on the module. These kinds of structuring are often used as antireflection and light-trapping tools. In the meantime, other solar technologies are considered, such as concentration photovoltaic modules. This article presents a module combining both approaches, that is, nanostructures and concentration, in order to increase the module's profitability. Sol-gel derived TiO 2 diffraction gratings, made by dynamic interferometric lithography, are added on the top of the glass cover to deflect unused light onto the solar cell, increasing the module efficiency
The Cyst-Dividing Bacterium Ramlibacter tataouinensis TTB310 Genome Reveals a Well-Stocked Toolbox for Adaptation to a Desert Environment
Ramlibacter tataouinensis TTB310T (strain TTB310), a betaproteobacterium isolated from a semi-arid region of South Tunisia (Tataouine), is characterized by the presence of both spherical and rod-shaped cells in pure culture. Cell division of strain TTB310 occurs by the binary fission of spherical “cyst-like” cells (“cyst-cyst” division). The rod-shaped cells formed at the periphery of a colony (consisting mainly of cysts) are highly motile and colonize a new environment, where they form a new colony by reversion to cyst-like cells. This unique cell cycle of strain TTB310, with desiccation tolerant cyst-like cells capable of division and desiccation sensitive motile rods capable of dissemination, appears to be a novel adaptation for life in a hot and dry desert environment. In order to gain insights into strain TTB310's underlying genetic repertoire and possible mechanisms responsible for its unusual lifestyle, the genome of strain TTB310 was completely sequenced and subsequently annotated. The complete genome consists of a single circular chromosome of 4,070,194 bp with an average G+C content of 70.0%, the highest among the Betaproteobacteria sequenced to date, with total of 3,899 predicted coding sequences covering 92% of the genome. We found that strain TTB310 has developed a highly complex network of two-component systems, which may utilize responses to light and perhaps a rudimentary circadian hourglass to anticipate water availability at the dew time in the middle/end of the desert winter nights and thus direct the growth window to cyclic water availability times. Other interesting features of the strain TTB310 genome that appear to be important for desiccation tolerance, including intermediary metabolism compounds such as trehalose or polyhydroxyalkanoate, and signal transduction pathways, are presented and discussed
Generalized Source method for ultrafast rigorous modeling of pixelated DOEs with sub-wavelength feature size
International audienceLarge, 2d-pixelated DOEs with subwavelength feature sizes are bringing the common rigorous calculation methods to their limits regarding memory usage and computation time. The generalized source method (GSM) breaks through this limitation, allowing for reasonable calculation times on a standard PC
- …