Evaluation of a high-throughput liquid crystal tunable filter for Raman chemical imaging of threat materials

2006 ◽  
Author(s):  
Xinghua Wang ◽  
Thomas C. Voigt ◽  
Philip J. Bos ◽  
Matthew P. Nelson ◽  
Patrick J. Treado
Keyword(s):  
Liquid Crystal ◽  
High Throughput ◽  
Chemical Imaging ◽  
Tunable Filter ◽  
Raman Chemical Imaging

Liquid Crystal Tunable Filter Raman Chemical Imaging

1996 ◽  
Vol 50 (6) ◽  
pp. 805-811 ◽  
Author(s):  
Hannah R. Morris ◽  
Clifford C. Hoyt ◽  
Peter Miller ◽  
Patrick J. Treado
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Free Spectral Range ◽  
Chemical Imaging ◽  
Tunable Filter ◽  
Raman Imaging ◽  
Model Systems ◽  
High Definition ◽  
Product Model ◽  
Raman Chemical Imaging

A Lyot-type liquid crystal tunable filter (LCTF) suitable for high-definition Raman chemical imaging has been developed. The LCTF has been incorporated into an efficient Raman imaging system that provides significant performance advantages relative to any previous approach to Raman microscopy. The LCTF and associated optical path is physically compact, which accommodates integration of the LCTF within an infinity-corrected optical microscope. The LCTF simultaneously provides diffraction-limited spatial resolution and 7.6-cm-1 spectral bandpass across the full free spectral range of the imaging spectrometer. The LCTF Raman microscope successfully integrates, in a facile manner, the utility of optical microscopy and the analytical capabilities of Raman spectroscopy. In this paper the LCTF Raman imaging system is described in detail, as well as results of initial studies of polymer and corrosion product model systems.

Raman Chemical Imaging of Microcrystallinity in Silicon Semiconductor Devices

2001 ◽  
Vol 55 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Michael D. Schaeberle ◽  
David D. Tuschel ◽  
Patrick J. Treado
Keyword(s):  
Integrated Circuits ◽  
Imaging System ◽  
Semiconductor Devices ◽  
Chemical Imaging ◽  
Tunable Filter ◽  
Resolving Power ◽  
High Definition ◽  
Semiconductor Wafer ◽  
Surface Distribution ◽  
Raman Chemical Imaging

Silicon integrated circuits are fabricated by the creation of complex layered structures. The complexity of these structures provides many opportunities for impurities, improperly annealed dopants, and stress effects to cause device contamination and failure. Nondestructive metrology techniques that rapidly and noninvasively screen for defects and relate silicon device structure to device performance are of value. We describe the first use of a liquid crystal tunable filter (LCTF) Raman chemical imaging microscope to assess the crystallinity of silicon semiconductor integrated circuits in a rapid and nondestructive manner without the need for sample preparation. The instrument has demonstrated lateral spatial resolving power of better than 250 nm and is equipped with a tunable imaging spectrometer having a spectral bandpass of 7.6 cm−1. The instrument rapidly produces high-definition Raman images where each image pixel contains a high-quality Raman spectrum. When combined with powerful processing strategies, the Raman chemical imaging system has demonstrated spectral resolving power of 0.03 cm−1 in a test silicon semiconductor wafer fabricated by using ion implantation. In addition, we have applied Raman chemical imaging for volumetric Raman imaging by analyzing the surface distribution of polycrystalline thin film structures. The approaches described here for the first time are generally applicable to the nondestructive metrology of silicon and compound semiconductor devices.

Detection and quantification of adulterants in milk powder using a high-throughput Raman chemical imaging technique

2016 ◽  
Vol 34 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Jianwei Qin ◽  
Moon S. Kim ◽  
Kuanglin Chao ◽  
Sagar Dhakal ◽  
Hoonsoo Lee ◽  
...  
Keyword(s):  
High Throughput ◽  
Imaging Technique ◽  
Milk Powder ◽  
Chemical Imaging ◽  
Raman Chemical Imaging ◽  
Detection And Quantification

Visualizing Molecular Species Within Inorganics: Raman Chemical Imaging of Minerals, Meteorites and Actinides

1997 ◽  
Vol 3 (S2) ◽  
pp. 859-860
Author(s):  
Nicole J. Kline ◽  
Mark C. Sparrow ◽  
Patrick J. Treado
Keyword(s):  
Imaging System ◽  
Optical Microscope ◽  
Chemical Imaging ◽  
Tunable Filter ◽  
Imaging Spectrometer ◽  
Composition And Structure ◽  
Inorganic Species ◽  
Raman Chemical Imaging ◽  
Mineral Components ◽  
Past Life

Raman chemical imaging microscopy is a powerful technique for the characterization of a wide host of materials, including inorganic species. The technique makes use of a liquid crystal tunable filter (LCTF) imaging spectrometer that is integrated within an infinity-corrected optical microscope. The imaging system provides the performance of a dispersive Raman spectrometer at every pixel of the charge-coupled device (CCD) detector used to capture the Raman image.We are currently applying Raman microscopy to the chemical imaging analysis of mineral composition and phase chemistry found in meteorites and terrestrial minerals. Determination of the chemical composition and structure of mineral components is often useful in developing an understanding of the petrologic process that formed the minerals, including those minerals that have been exposed to water. This is of particular interest in light of recent promising evidence of past life in Martian meteorites.

A Line-Scan Hyperspectral System for High-Throughput Raman Chemical Imaging

2014 ◽  
Vol 68 (6) ◽  
pp. 692-695 ◽  
Author(s):  
Jianwei Qin ◽  
Kuanglin Chao ◽  
Moon S. Kim
Keyword(s):  
High Throughput ◽  
Chemical Imaging ◽  
Line Scan ◽  
Raman Chemical Imaging
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