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Two-Channel Optoelectronic Sensor Employing Cavity Enhanced Absorption Spectroscopy

100%
Wojtas J.
Acta Physica Polonica A
|
2011
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vol. 120
|
issue 4
763-766
EN
In the paper, a description of two-channel of optoelectronic sensor basing on cavity enhanced absorption spectroscopy is presented. In contrast to the typical cavity enhanced absorption spectroscopy systems, here a special optical system is applied. It provides possibility to direct more than one beam of laser radiation into a cavity. Thus, special lasers controller system and photoreceiver were developed as well. The setup includes two pulsed laser diodes. The optical signals from the lasers are registered with one special constructed photoreceiver, which is characterized by wide range of the detected wavelengths. Moreover, there was applied time division multiplexing technique, well-known in the telecommunication systems. Every laser is assigned to the suitable channel - the strictly determined temporary window. In this window, the signal from the exits of the optical cavity is registered. In the system, optical signal from many laser sources can be measured and value of absorption coefficient at a few different wavelengths can be determined parallel. Typical cavity enhanced absorption spectroscopy system is designed to measure only one gas concentration, while the developed setup provides possibility to detect a trace concentration of two gases at the same time.
2
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Application of quantum cascade lasers to trace gas detection

51%
Bielecki Z., Wojtas J., Stacewicz T., Mikołajczyk J.
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2015
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issue 2
3
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Cavity Enhanced Absorption Spectroscopy Sensor

51%
Nowakowski M., Wojtas J., Bielecki Z., Mikołajczyk J.
Acta Physica Polonica A
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2009
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vol. 116
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issue 3
363-367
EN
The paper presents opportunities of cavity enhanced absorption spectroscopy technique application in nitrogen oxides (NO_{x}) detection. In this method the concentration of an absorbing gas is determined by measure of decay time of the light pulse trapped in an optical cavity. The measurements are not sensitive to fluctuation of both laser power and photodetector sensitivity. The cavity enhanced absorption spectroscopy technique is a modification of cavity ring down spectroscopy technique where the off-axis adjustment of the resonator is used. NO_{x} detection is carried out in the visible and infrared range. The signal is registered with a developed low noise photoreceiver. Features of the presented sensor show that it is possible to build a portable trace gases sensor. Its sensitivity could be comparable with chemical detectors. Such a system has several advantages: relatively low price, small size and weight, and detection possibility of other gases.
4
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Compact QCL driver for free-space transmitter

45%
Mikołajczyk J., Wesołowski M., Wojtas J., Garlińska M., Bielecki Z.
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2012
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issue 4
5
Content available remote

Application of Quantum Cascade Lasers in Nitric Oxide and Nitrous Oxide Detection

39%
Wojtas J., Bielecki Z., Stacewicz T., Mikolajczyk J., Medrzycki R., Rutecka B.
Acta Physica Polonica A
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2011
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vol. 120
|
issue 4
794-797
EN
Application of quantum cascade lasers in NO and N_2O sensor is described. Cavity enhanced absorption spectroscopy was used for this purpose. The detection was performed at vibronic molecular transitions in spectral regions of 5.23-5.29 μm and 4.46-4.54 μm for NO and N_2O, respectively. In order to avoid interferences by the gases contained in atmosphere (H_2O, CO_2) the lines of 5.263 μm for NO and 4.530 μm for N_2O were selected. Our two channel sensor is designated for simultaneous detection of both compounds. Each channel consists of single mode quantum cascade laser, optical cavity, and a photodetection module. The lasers were precisely tuned to the wavelength of interest. Optical cavities were built with spherical mirrors of high reflectance. The signals from the cavities outputs were registered with specially developed low noise detection modules.
6
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Investigations of Quantum Cascade Lasers for Free Space Optics Operating at the Wavelength Range of 8-12 μm

39%
Nowakowski M., Gutowska M., Szabra D., Mikołajczyk J., Wojtas J., Bielecki Z.
Acta Physica Polonica A
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2011
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vol. 120
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issue 4
705-708
EN
The paper presents analysis and preliminary investigations of quantum cascade lasers for free space optics. The lasers radiate in the long wavelength IR spectral range (8-12 μm). Because of lower effects of radiation scattering than in the case of 1.5 μm free space optics, better transmission range can be obtained. The main task of the work was experimental investigation of quantum cascade lasers taking into consideration free space optics applications. In the research, quantum cascade lasers operating in both pulse and continuous wave modes were used. The lasers spectra as well as the operation characteristics (e.g. voltage vs. current) were measured. In conclusion, the quantum cascade lasers parameters for free space optics system applications are summarized.
7
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Nitrogen Oxides Optoelectronic Sensors Operating in Infrared Range of Wavelengths

39%
Wojtas J., Bielecki Z., Stacewicz T., Mikolajczyk J., Rutecka B., Medrzycki R.
Acta Physica Polonica A
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2013
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vol. 124
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issue 3
592-594
EN
Investigation of nitric oxide and nitrous oxide optoelectronic sensors is described. The detection of both components was done by measurement of absorption that occurs due to transition between vibronic molecular transitions. The improvement of the sensitivity was achieved due to application of cavity enhanced absorption spectroscopy. Two optical cavities (each one for each gas) built of high reflectance spherical mirrors were used. While the spectra of observed transitions are situated in mid-infrared range, two single mode quantum cascade lasers were applied. Their narrow emission lines were precisely tuned to the absorption lines of both investigated gases. The measurement of different mixtures of Ar-NO and Ar-N_2O within the range from 100 ppb to 10 ppm was performed. The relative uncertainty of the results did not exceed the level of 13%.
8
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Applying CEAS method to UV, VIS, and IR spectroscopy sensors

39%
Wojtas J., Mikolajczyk J., Nowakowski M., Rutecka B., Medrzycki R., Bielecki Z.
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2011
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issue 4
9
Content available remote

Laboratory System for Quantum Cascade Lasers Researching

39%
Mikołajczyk J., Pichola W., Wojtas J., Mamajek M., Garlińska M., Prokopiuk A., Bielecki Z.
Acta Physica Polonica A
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2013
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vol. 124
|
issue 3
505-508
EN
The paper presents a prototype of a driving system designed to laboratory investigations of quantum cascade lasers. Significant requirements of these lasers operation, as well as a construction of the main components of the system were analyzed. During the performed investigations, a tuning range of both current pulses and temperature control operation were determined. Additionally the method of monitoring both current and voltage of the lasers was also described. As a summary, results of laboratory studies of the system with the use of commercial quantum cascade lasers were presented.
10
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Explosives Vapors–Concentrating and Optoelectronic Detection

33%
Wojtas J., Rutecka B., Popiel S., Nawała J., Wesołowski M., Mikołajczyk J., Cudziło S., Bielecki Z.
Metrology and Measurement Systems
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2014
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issue 2
11
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Transmitter with quantum cascade laser for free space optics communication system

33%
Gutowska M., Wojtas J., Pierścińska D., Nowakowski M., Pierściński K., Szabra D., Mikołajczyk J., Bielecki Z.
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2011
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issue 4
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