Dielectric filters made of PS: advanced performance by oxidation and new layer structures

Berger, M.; Arens-Fischer, R.; Thönissen, M.; Krüger, Michael; Billat, S.; Lüth, H.; Hilbrich, S.; Theiß, W.; Große, Peter

doi:10.1016/s0040-6090(96)09361-3

Cited by 149 publications

(94 citation statements)

References 13 publications

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“…This feature allows the construction of layered nanostructures simply by modulating the applied current during an etch. For example, one-dimensional photonic crystals consisting of a stack of layers with alternating refractive index can be prepared by periodically modulating the current during an etch [40][41][42].…”

Section: Electrochemical Etchingmentioning

confidence: 99%

Porous silicon in drug delivery devices and materials☆

Anglin

Cheng

Freeman

et al. 2008

Advanced Drug Delivery Reviews

807

618

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Porous Si exhibits a number of properties that make it an attractive material for controlled drug delivery applications: The electrochemical synthesis allows construction of tailored pore sizes and volumes that are controllable from the scale of microns to nanometers; a number of convenient chemistries exist for the modification of porous Si surfaces that can be used to control the amount, identity, and in vivo release rate of drug payloads and the resorption rate of the porous host matrix; the material can be used as a template for organic and biopolymers, to prepare composites with a designed nanostructure; and finally, the optical properties of photonic structures prepared from this material provide a self-reporting feature that can be monitored in vivo. This paper reviews the preparation, chemistry, and properties of electrochemically prepared porous Si or SiO 2 hosts relevant to drug delivery applications.

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Section: Electrochemical Etchingmentioning

confidence: 99%

Porous silicon in drug delivery devices and materials☆

Anglin

Cheng

Freeman

et al. 2008

Advanced Drug Delivery Reviews

807

618

View full text Add to dashboard Cite

show abstract

“…If the index contrast is modulated with a smooth function, these sidelobes can be suppressed. 19,23,24 There are many windows that can be used to truncate a function more smoothly: a triangle, a Gaussian, a sine, and other examples taken from signal processing theory, such as Kaiser windows. The apodization can be applied to a DBR or a rugate filter, and in both cases sidelobes can be suppressed.…”

Section: Apodizationmentioning

confidence: 99%

“…Birefringent rugate filters have been reported too. 18 In 1997 Berger et al reported the first porous silicon-based rugate filter, 19 and Cunin et al showed an application for biomolecular screening. 20 Also, vacuum-evaporated PS permits a periodic smooth variation of porosity.…”

Section: Introductionmentioning

confidence: 99%

Porous silicon-based rugate filters

et al. 2005

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We report an experimental study of porous silicon-based rugate filters. We performed filter apodization, following a half-apodization approach, which successfully attenuated the sidelobes at both sides of the photonic stop band. We achieved successful reduction of interference ripples through the insertion of index-matching layers on the first and last interfaces. An apodized dielectric mirror and a rugate filter are compared: Appreciable differences in the harmonic presence and stop-band performance were observed and are commented on. Bandwidth control when index contrast is modified is also demonstrated. Finally, the possibility of combining different rugate filter designs to attain more complex responses is demonstrated by the achievement of a multi-stop-band filter. Numerical calculations for design optimization and comparison with experimental data are reported too.

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“…Depending on several parameters such as Si wafer dopant type and resistivity, current density, and electrolyte composition, a wie range of pore sizes and morphologies can be obtained. 14,15 In addition, the pore diameters can be systematically varied in either horizontal or vertical directions (relative to the wafer surface), leading to pore gradient 11-13 and multilayer [16][17][18] structures.…”

mentioning

confidence: 99%

Biosensing Using Porous Silicon Double-Layer Interferometers: Reflective Interferometric Fourier Transform Spectroscopy

et al. 2005

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A simple, chip-based implementation of a double-beam interferometer that can separate biomolecules based on size and that can compensate for changes in matrix composition is introduced. The interferometric biosensor uses a double-layer of porous Si comprised of a top layer with large pores and a bottom layer with smaller pores. The structure is shown to provide an on-chip reference channel analogous to a double-beam spectrometer, but where the reference and sample compartments are stacked one on top of the other. The reflectivity spectrum of this structure displays a complicated interference spectrum whose individual components can be resolved by fitting of the reflectivity data to a simple interference model or by fast Fourier transform (FFT). Shifts of the FFT peaks indicate biomolecule penetration into the different layers. The small molecule sucrose penetrates into both porous Si layers, whereas the large protein bovine serum albumin (BSA) only enters the large pores. BSA can be detected even in a large (100-fold by mass) excess of sucrose from the FFT spectrum. Detection can be accomplished either by computing the weighted difference in the frequencies of two peaks or by computing the ratio of the intensities of two peaks in the FFT spectrum.

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Dielectric filters made of PS: advanced performance by oxidation and new layer structures

Cited by 149 publications

References 13 publications

Porous silicon in drug delivery devices and materials☆

Porous silicon in drug delivery devices and materials☆

Porous silicon-based rugate filters

Biosensing Using Porous Silicon Double-Layer Interferometers: Reflective Interferometric Fourier Transform Spectroscopy

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