Mid-IR evanescent-wave absorption spectra of thin films and coatings measured with a ~50-um-thick planar Ge waveguide sensor

1997 ◽  
Author(s):  
James J. Stone ◽  
Mark S. Braiman ◽  
Susan E. Plunkett
Keyword(s):  
Thin Films ◽  
Absorption Spectra ◽  
Evanescent Wave ◽  
Wave Absorption ◽  
Waveguide Sensor

Design for Supported Planar Waveguides for Obtaining Mid-IR Evanescent-Wave Absorption Spectra from Biomembranes of Individual Cells

1997 ◽  
Vol 51 (4) ◽  
pp. 592-597 ◽  
Author(s):  
Mark S. Braiman ◽  
Susan E. Plunkett
Keyword(s):  
Ion Channel ◽  
Absorption Spectra ◽  
Evanescent Wave ◽  
Broad Band ◽  
Coupling Efficiency ◽  
Planar Waveguides ◽  
Voltage Gated ◽  
Wave Absorption ◽  
Channel Proteins ◽  
Ion Channel Proteins

We have been developing miniature planar Ge waveguides to detect mid-IR evanescent-wave absorption spectra from the cell membranes of individual intact frog eggs, 1.5-mm in diameter, from Xenopus laevis, with the aim of detecting and analyzing transient conformational changes of voltage-gated ion channel proteins in the membrane. Here we use waveguide optical theory to calculate optimal dimensions for a germanium waveguide to be used as a multiple-internal-reflection ATR element for this purpose. We assume that light from a standard broad-band IR source is coupled efficiently into and out of a planar Ge waveguide, and then onto a small-area MCT detector, by using an IR microscope with a high-numerical-aperture objective. To increase the coupling efficiency even further, we assume that we can fabricate the waveguide with a gradual 7-fold-tapering to the tiny dimensions needed in the sensing region. Then, assuming that ∼ 107 ion channel proteins in an occyte can be made to contact an area of a planar Ge waveguide up to ∼ 200 μm in diameter, we calculate that voltage-gated structural changes in these channel proteins should produce absorbance change signals of ∼ 10−6 if the waveguide sensor thickness is set near the optimal thickness of ∼ 1 μm and the sensor region length is limited to 100 μm. If such a sensor can be fabricated, we calculate that detection of the predicted voltage-gated absorbance changes with a commercial FT-IR microscope should be possible after ∼ 20 min of signal averaging.

Temperature Effects on a Fiber-Optic Evanescent Wave Absorption Sensor

1994 ◽  
Vol 48 (3) ◽  
pp. 387-393 ◽  
Author(s):  
G. L. Klunder ◽  
J. BÜrck ◽  
H.-J. Ache ◽  
R. J. Silva ◽  
R. E. Russo
Keyword(s):  
Absorption Spectra ◽  
Evanescent Wave ◽  
Near Infrared ◽  
Chemical Sensor ◽  
Fiber Optic ◽  
Absorption Bands ◽  
Wave Absorption ◽  
Influence Of Temperature On ◽  
Background Absorption ◽  
Cladding Material

A coiled fiber-optic chemical sensor has proven to be effective for the remote detection of volatile organic compounds, such as trichloroethylene (TCE), 1,1-dichloroethylene (DCE), and gasoline, in aqueous solutions. The analyte diffuses into the hydrophobic cladding and evanescent wave absorption spectra are measured in the near-infrared (1600–1850 nm) without the presence of the water absorption bands. In order for fiberoptic chemical sensors to operate effectively in remote environments, the influence of temperature on the sensor response must be known. The C-H bonds of the polysiloxane cladding material also have absorption bands in the near-infrared (NIR). Changes in temperature will change the density (i.e., concentration of C-H bonds) and refractive index of the cladding. Due to these effects, a temperature change of only 3°C from the reference has been shown to significantly alter the background absorbance. The temperature-dependent background absorption is found to be linear with the slope, and the values are proportional to the absorption coefficient of the cladding material. The intercept of the absorbance vs. temperature plot is found to follow the first derivative of the fiber sensor transmission spectrum. Evanescent wave absorption spectra of TCE solutions have been corrected for temperature.

Kramers–Kronig analysis of molecular evanescent-wave absorption spectra obtained by multimode step-index optical fibers

1996 ◽  
Vol 35 (21) ◽  
pp. 4102 ◽  
Author(s):  
Radislav A. Potyrailo ◽  
Vincent P. Ruddy ◽  
Gary M. Hieftje
Keyword(s):  
Absorption Spectra ◽  
Optical Fibers ◽  
Evanescent Wave ◽  
Wave Absorption ◽  
Step Index

scholarly journals Evanescent Wave Absorption Based S-shaped Fiber-optic Biosensor for Immunosensing Applications

2016 ◽  
Vol 168 ◽  
pp. 117-120 ◽  
Author(s):  
S. Chauhan ◽  
N. Punjabi ◽  
D. Sharma ◽  
S. Mukherji
Keyword(s):  
Evanescent Wave ◽  
Fiber Optic ◽  
Wave Absorption

Sapphire Fiber Evanescent Wave Absorption in Turbid Media

2009 ◽  
Vol 63 (8) ◽  
pp. 932-935 ◽  
Author(s):  
Jian Zhang ◽  
Feibing Xiong ◽  
Nicholas Djeu
Keyword(s):  
Glassy Carbon ◽  
Chemical Sensors ◽  
Evanescent Wave ◽  
Fiber Optic ◽  
Wave Interaction ◽  
Carbon Powder ◽  
Control Applications ◽  
Wave Absorption ◽  
Water Band ◽  
Sapphire Fiber

The influence of particulates on sapphire fiber evanescent wave absorption by water has been studied. Suspensions containing microsized graphite flakes and glassy carbon powder were used. Conventional free-space transmittance measurements of these samples showed strong absorption and scattering, which severely screened the absorption by water. However, the absorption on the water band determined from the evanescent wave interaction was unaffected by the presence of the graphite flakes. These results indicate that fiber-optic evanescent wave chemical sensors may be suitable for process control applications involving turbid reactor streams.

Millimeter wave absorption spectra of biological samples

1980 ◽  
Vol 1 (3) ◽  
pp. 285-298 ◽  
Author(s):  
O. P. Gandhi ◽  
M. J. Hagmann ◽  
D. W. Hill ◽  
L. M. Partlow ◽  
L. Bush
Keyword(s):  
Absorption Spectra ◽  
Millimeter Wave ◽  
Biological Samples ◽  
Wave Absorption

Reversible All-Optical Modulation Based on Evanescent Wave Absorption of a Single-Mode Fiber With Azo-Polymer Overlay

2010 ◽  
Vol 22 (18) ◽  
pp. 1352-1354 ◽  
Author(s):  
Xiujie Tian ◽  
Xusheng Cheng ◽  
Wenxuan Wu ◽  
Yanhua Luo ◽  
Qijin Zhang ◽  
...  
Keyword(s):  
Evanescent Wave ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Optical Modulation ◽  
Wave Absorption ◽  
Azo Polymer ◽  
All Optical
Sign in / Sign up

Export Citation Format

Share Document