Dual-Beam Thermal Lens Measurement of Condensed-Phase Sample at CO2 Laser Wavelengths: Detection of Octadecanoic Acid in Carbon Tetrachloride

1994 ◽  
Vol 48 (12) ◽  
pp. 1457-1460 ◽  
Author(s):  
Mladen Franko ◽  
Dane Bicanic ◽  
Zoltán Bozóki ◽  
Henk Jalink
Keyword(s):  
Laser Radiation ◽  
Detection Limit ◽  
Thermal Lens ◽  
Limit Of Detection ◽  
Octadecanoic Acid ◽  
Straight Chain ◽  
Dual Beam ◽  
Phase Sample ◽  
Thermal Lens Effect ◽  
First Time

Detection of monobasic, straight-chain saturated fatty acid (octadecanoic C18:0) in CCl4, based on the thermal lens effect after excitation by CO2 laser radiation at 934.9 cm−1, is described for the first time. The achieved limit of detection (LOD = 0.3%) is comparable to that of the transmission infrared technique. Possibilities for further improvements in sensitivity and detection limit are also discussed.

Development of a Multiwavelength Thermal Lens Spectrophotometer Based on an Acousto-Optic Tunable Filter as a Polychromator

1994 ◽  
Vol 48 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Chieu D. Tran ◽  
Ricardo J. Furlan ◽  
Jian Lu
Keyword(s):  
Detection Limit ◽  
Thermal Lens ◽  
Laser Light ◽  
Limit Of Detection ◽  
Tunable Filter ◽  
Lanthanide Ions ◽  
Probe Laser ◽  
Excitation Beam ◽  
Thermal Lens Signal ◽  
Rf Signals

Instrumentation development of a novel multiwavelength thermal lens spectrophotometer which has the capability of achieving truly multiwavelength excitation is described. The spectrophotometer is based on a new concept by which the sample is excited by multiwavelength excitation beams simultaneously, not sequentially as in previously reported multiwavelength thermal lens apparatus. This was accomplished by use of the acousto-optic tunable filter (AOTF) as a polychromator. Specifically, four different rf signals were simultaneously applied to the filter to enable it to diffract incident multiline laser light into a beam which contained four different wavelengths. This multiwavelength beam was then used to excite the sample, and the corresponding thermal lens signal was measured by a He-Ne probe laser. Compared with other multiwavelength thermal lens instruments, this all-solid-state thermal lens spectrophotometer has advantages that include its ability to simultaneously analyze multicomponent samples in microsecond times scale, without the need for any prior sample preparation. With this apparatus and with the use of a 12-mW multiwavelength excitation beam, the limit of detection for four-component (lanthanide ions) samples is estimated to be 10−6 cm−1, which is similar to the detection limit obtained for one-component samples with the use of a single-wavelength system.

scholarly journals Realization of Optical Logic Gates Using the Thermal Lens Effect

2002 ◽  
Vol 20 (2-4) ◽  
pp. 81-87 ◽  
Author(s):  
Achamma Kurian ◽  
K. P. Unnikrishnan ◽  
Thomas Lee S. ◽  
V. P. N. Nampoori ◽  
C. P. G. Vallabhan
Keyword(s):  
Thermal Lens ◽  
Logic Gates ◽  
Optical Logic ◽  
Logical Function ◽  
Optical Logic Gates ◽  
Dual Beam ◽  
Photothermal Phenomena ◽  
Thermal Lens Effect ◽  
Doped Polymer ◽  
Sensitive Method

A sensitive method based on the principle of photothermal phenomena to realize optical logic gates is presented. A dual beam thermal lens method using low power cw lasers in a dye-doped polymer can be very effectively used as an alternate technique to perform the logical function such as NAND, AND and OR.

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

Thermal Diffusivity Dependence with Highly Concentrated Graphene Oxide/Water Nanofluids by Mode-Mismatched Dual-Beam Thermal Lens Technique

2021 ◽  
Vol 42 (7) ◽  
Author(s):  
J. L. Jiménez-Pérez ◽  
G. López-Gamboa ◽  
J. F. Sánchez-Ramírez ◽  
Z. N. Correa-Pacheco ◽  
A. Netzahual‑Lopantzi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Thermal Diffusivity ◽  
Thermal Lens ◽  
Dual Beam

Thermal lens investigation of the Acid Blue 29 using dual beam z-scan technique

Optik ◽  
2021 ◽  
pp. 168499
Author(s):  
A. Ghanem ◽  
M.D. Zidan ◽  
M.S. EL-Daher ◽  
A. Allahham
Keyword(s):  
Thermal Lens ◽  
Dual Beam ◽  
Acid Blue

Two Orders of Magnitude Improvement in the Detection Limit of Droplet-Based Micro-Magnetofluidics with Planar Hall Effect Sensors

2021 ◽  
Vol 6 (1) ◽  
pp. 47
Author(s):  
Julian Schütt ◽  
Rico Illing ◽  
Oleksii Volkov ◽  
Tobias Kosub ◽  
Pablo Nicolás Granell ◽  
...  
Keyword(s):  
Detection Limit ◽  
Hall Effect ◽  
State Of The Art ◽  
Limit Of Detection ◽  
Research Field ◽  
High Throughput Analysis ◽  
Planar Hall Effect ◽  
Biologically Relevant ◽  
Sensing Platform ◽  
Order Of Magnitude

The detection, manipulation, and tracking of magnetic nanoparticles is of major importance in the fields of biology, biotechnology, and biomedical applications as labels as well as in drug delivery, (bio-)detection, and tissue engineering. In this regard, the trend goes towards improvements of existing state-of-the-art methodologies in the spirit of timesaving, high-throughput analysis at ultra-low volumes. Here, microfluidics offers vast advantages to address these requirements, as it deals with the control and manipulation of liquids in confined microchannels. This conjunction of microfluidics and magnetism, namely micro-magnetofluidics, is a dynamic research field, which requires novel sensor solutions to boost the detection limit of tiny quantities of magnetized objects. We present a sensing strategy relying on planar Hall effect (PHE) sensors in droplet-based micro-magnetofluidics for the detection of a multiphase liquid flow, i.e., superparamagnetic aqueous droplets in an oil carrier phase. The high resolution of the sensor allows the detection of nanoliter-sized superparamagnetic droplets with a concentration of 0.58 mg cm−3, even when they are only biased in a geomagnetic field. The limit of detection can be boosted another order of magnitude, reaching 0.04 mg cm−³ (1.4 million particles in a single 100 nL droplet) when a magnetic field of 5 mT is applied to bias the droplets. With this performance, our sensing platform outperforms the state-of-the-art solutions in droplet-based micro-magnetofluidics by a factor of 100. This allows us to detect ferrofluid droplets in clinically and biologically relevant concentrations, and even in lower concentrations, without the need of externally applied magnetic fields.

scholarly journals Studies on Fluorescence Efficiency and Photodegradation of Rhodamine 6G Doped PMMA Using a Dual Beam Thermal Lens Technique

2002 ◽  
Vol 20 (2-4) ◽  
pp. 99-110 ◽  
Author(s):  
Achamma Kurian ◽  
Nibu A. George ◽  
Binoy Paul ◽  
V. P. N. Nampoori ◽  
C. P. G. Vallabhan
Keyword(s):  
Thermal Lens ◽  
Fluorescence Quantum Yield ◽  
Laser Excitation ◽  
Rhodamine 6G ◽  
Fluorescence Emission ◽  
Concentration Quenching ◽  
Dye Molecules ◽  
Dual Beam ◽  
Fluorescence Efficiency ◽  
Absolute Fluorescence

In this paper we report the use of the dual beam thermal lens technique as a quantitative method to determine absolute fluorescence quantum efficiency and concentration quenching of fluorescence emission from rhodamine 6G doped Poly(methyl methacrylate) (PMMA), prepared with different concentrations of the dye. A comparison of the present data with that reported in the literature indicates that the observed variation of fluorescence quantum yield with respect to the dye concentration follows a similar profile as in the earlier reported observations on rhodamine 6G in solution. The photodegradation of the dye molecules under cw laser excitation is also studied using the present method.

Stabilization of the output power of a cw laser by the thermal lens effect

1990 ◽  
Vol 20 (1) ◽  
pp. 52-53
Author(s):  
A I Larkin ◽  
Yu A Mironov ◽  
V M Petropavlovskiĭ
Keyword(s):  
Output Power ◽  
Thermal Lens ◽  
Lens Effect ◽  
Cw Laser ◽  
Thermal Lens Effect
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