Elongation-based fiber optic tunable filter

Author(s):  
Grethell G. Pérez-Sánchez ◽  
José A. Mejía-Islas ◽  
Edgar A. Andrade-González ◽  
José R. Pérez-Torres
Keyword(s):  
1998 ◽  
Vol 52 (5) ◽  
pp. 717-724 ◽  
Author(s):  
Charity Coffey ◽  
Alex Predoehl ◽  
Dwight S. Walker

The monitoring of the effluent of a rotary dryer has been developed and implemented. The vapor stream between the dryer and the vacuum is monitored in real time by a process fiber-optic coupled near-infrared (NIR) spectrometer. A partial least-squares (PLS) calibration model was developed on the basis of solvents typically used in a chemical pilot plant and uploaded to an acousto-optic tunable filter NIR (AOTF-NIR). The AOTF-NIR is well suited to process monitoring as it electrically scans a crystal and hence has no moving parts. The AOTF-NIR continuously fits the PLS model to the currently collected spectrum. The returned values can be used to follow the drying process and determine when the material can be unloaded from the dryer. The effluent stream was monitored by placing a gas cell in-line with the vapor stream. The gas cell is fiber-optic coupled to a NIR instrument located 20 m away. The results indicate that the percent vapor in the effluent stream can be monitored in real time and thus be used to determine when the product is free of solvent.


1998 ◽  
Vol 10 (3) ◽  
pp. 361-363 ◽  
Author(s):  
H.G. Limberger ◽  
Nguyen Hong Ky ◽  
D.M. Costantini ◽  
R.P. Salathe ◽  
C.A.P. Muller ◽  
...  

2019 ◽  
Vol 1221 ◽  
pp. 012018
Author(s):  
L.V. Olarte-Pérez ◽  
G.G. Pérez-Sánchez ◽  
M.A. Soto-Jasso ◽  
G. Hernández-Valdez

1996 ◽  
Vol 50 (4) ◽  
pp. 498-503 ◽  
Author(s):  
David P. Baldwin ◽  
Daniel S. Zamzow ◽  
Arthur P. D'Silva

A compact, solid-state, high-resolution spectrometer consisting of an acousto-optic tunable filter (AOTF) and a fiber-optic Fabry-Perot (FFP) interferometer has been developed. The system has been designed for high-resolution inductively coupled plasma atomic emission spectroscopy (ICP-AES) applications. A description of the AOTF-FFP and its performance is presented. The resolution of the AOTF-FFP was determined by measuring the physical widths of ICP emission lines using a 1.5-m-focal-length grating spectrometer and deconvoluting the physical line shapes from the acquired AOTF-FFP spectra. Over the optimum range of the FFP mirror coatings, the resolution is sufficient for the determination of isotopic and hyperfine emission features in ICP-AES experiments, and approaches that of the 1.5-m spectrometer. The application of the AOTF-FFP to the determination of uranium isotopes (U-235 and U-238) introduced into the ICP is presented.


1996 ◽  
Vol 50 (10) ◽  
pp. 1295-1300 ◽  
Author(s):  
Frédérick Moreau ◽  
Sandrine M. Moreau ◽  
Dennis M. Hueber ◽  
Tuan Vo-Dinh

This paper describes a new fiber-optic multisensor based on an acousto-optic tunable filter (AOTF) and capable of remote sensing using a multioptical fiber array (MOFA). A two-dimensional charge-coupled device (CCD) was used as a detector, and the AOTF was used as a wavelength selector. Unlike a tunable grating or prism-based monochromator, an AOTF has no moving parts, and an AOTF can be rapidly tuned to any wavelength in its operating range within microseconds. The large aperture of the AOTF allows the optical signal from over 100 fiber-optic sensors to be measured simultaneously. These characteristics, combined with their small size, make AOTFs an important new alternative to conventional monochromators, especially for spectral multisensing and imaging. A prototype fiber-optic multisensor system has been developed, and its feasibility for simultaneous detection of molecular luminescence signal via fiber-optic probes is demonstrated.


2012 ◽  
Vol 37 (4) ◽  
pp. 626 ◽  
Author(s):  
Yunhae Yeh ◽  
Se Hoon Park

1996 ◽  
Vol 50 (8) ◽  
pp. 1007-1014 ◽  
Author(s):  
H. Trey Skinner ◽  
Thomas F. Cooney ◽  
S. K. Sharma ◽  
S. M. Angel

A fiber-optic Raman microimaging probe is described that is suitable for acquiring high-spatial-resolution Raman images in sampling situations with no clear line of sight. A high-power near-infrared diode laser combined with an acousto-optic tunable filter and a spatially coherent optical fiber bundle allow fluorescence-free Raman images of remotely located samples to be acquired at distances up to several meters. The feasibility of this technique is demonstrated with Raman images of (1) a pellet containing a mixture of a highly scattering sample, bis-methylstyrylbenzene (BMSB), KCl, and graphite, and (2) a partially graphitized diamond. These images clearly show phase boundaries over an area of approximately 0.1 mm2 with ∼4-μm resolution.


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