Vacuum-metal-deposition and columnar-thin-film techniques implemented in the same apparatus

Swiontek, Stephen E.; Lakhtakia, Akhlesh

doi:10.1016/j.matlet.2014.12.038

Cited by 10 publications

(5 citation statements)

References 12 publications

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“…Each periodic multilayer was fabricated using thermal evaporation [19] implemented inside a low-pressure chamber from Torr International (New Windsor, NY, USA). It contains a quartz crystal monitor (QCM) calibrated to measure the growing thin-film's thickness, a receptacle to hold the material to be evaporated, electrodes to resistively heat the receptacle, and a substrate holder positioned about 15 cm above the receptacle.…”

Section: Fabrication Of Periodic Multilayers Comprising Ctfsmentioning

confidence: 99%

Nonexhibition of Bragg phenomenon by chevronic sculptured thin films: experiment and theory

2017

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The unit cell of a chevronic sculptured thin film (ChevSTF) comprises two identical columnar thin films (CTFs) except that the nanocolumns of the first are oriented at an angle χ and nanocolumns of the second are oriented at an angle π − χ with respect to the interface of the two CTFs. A ChevSTF containing 10 unit cells was fabricated using resistive-heating physical vapor deposition of zinc selenide. Planewave reflectance and transmittance spectrums of this ChevSTF were measured for a wide variety of incidence conditions over the 500-900-nm range of the free-space wavelength. Despite its structural periodicity, the ChevSTF did not exhibit the Bragg phenomenon. Theoretical calculations with the CTFs modeled as biaxial dielectric materials indicated that the Bragg phenomenon would not be manifested for normal and near-normal incidence, but vestigial manifestation was possible for sufficiently oblique incidence. Thus, structural periodicity does not always lead to electromagnetic periodicity that underlies the exhibition of the Bragg phenomenon.

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Section: Fabrication Of Periodic Multilayers Comprising Ctfsmentioning

confidence: 99%

Nonexhibition of Bragg phenomenon by chevronic sculptured thin films: experiment and theory

2017

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“…A custom-built low-pressure chamber from Torr International (New Windsor, New York) was used for physical vapor deposition. 32 A gold pellet (EVMAU40SHOT, K. J.…”

Section: Deposition Of Au Thin Filmmentioning

confidence: 99%

Experimental detection of Immunoglobulin G by prism-coupled angular interrogation and a support vector machine

McAtee

Lakhtakia

2022

J. Nanophoton.

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A typical prism-coupled surface-plasmon-resonance biosensor comprises a metal thin film in contact with a solution containing an analyte to be sensed. The metal film also acts as a binding surface for bioreceptor molecules to capture and concentrate the analyte molecules of interest. We investigated the use of a porous, anisotropic, periodically non-homogeneous material called a chiral sculptured thin film (CSTF) grown on top of the metal film to confine the solution in its pores. The efficacy of a basic plasmonic sensor was compared with those of two types of sensors containing a CSTF, one type having a metal-nanoparticle layer at a distance of one period from the metal film and the other without that layer. The chosen analyte was Immunoglobulin G (IgG) and the chosen bioreceptor was Protein A.Measurements were made over a wide angular range rather than over a small range tied to the excitation of a surfaceplasmon-polariton wave and the collected data were used to train a machine-learning algorithm called a support vector machine for classification. We concluded that the metal/CSTF sensor with a metal-nanoparticle layer performs best, the metal-nanoparticle layer being crucial to its better performance.

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“…The CSTF for this project was fabricated using thermal evaporation implemented inside a low-pressure chamber [31] from Torr International (New Windsor, New York). It contains a quartz crystal monitor calibrated to measure the growing thin-film's thickness, a receptacle to hold the material to be evaporated to generate a collimated vapor flux, electrodes to resistively heat the receptacle, and a substrate holder positioned about 15 cm directly above the receptacle.…”

Section: Fabrication Of Cstfmentioning

confidence: 99%

Experimental and theoretical investigation of the co-occurrence of linear and circular dichroisms for oblique incidence of light on chiral sculptured thin films

McAtee

Lakhtakia

2018

J. Opt. Soc. Am. A

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Theory shows that a slab of a dielectric structurally chiral material (DSCM) exhibits both linear and circular dichroisms because of its anisotropy and structural chirality, for normal as well as oblique incidence. This conclusion was confirmed by fabricating a chiral sculptured thin film and measuring the spectra of its reflectances and transmittances, both linear and circular. Signatures of the circular Bragg phenomenon are evident in the spectra of all reflectances, transmittances, absorptances, and dichroisms. Reversal of the structural handedness of a DSCM and rotation of the projection of the direction of propagation of the incident light clockwise instead of counterclockwise about the axis of helicoidal nonhomogeneity simultaneously changes the sign of circular dichroism but has no effect on linear dichroism.

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Vacuum-metal-deposition and columnar-thin-film techniques implemented in the same apparatus

Cited by 10 publications

References 12 publications

Nonexhibition of Bragg phenomenon by chevronic sculptured thin films: experiment and theory

Nonexhibition of Bragg phenomenon by chevronic sculptured thin films: experiment and theory

Experimental detection of Immunoglobulin G by prism-coupled angular interrogation and a support vector machine

Experimental and theoretical investigation of the co-occurrence of linear and circular dichroisms for oblique incidence of light on chiral sculptured thin films

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