Zbigniew Bielecki - Academia.edu (original) (raw)

Papers by Zbigniew Bielecki

Applied Sciences

This paper presents the design and testing of an ultra-low-noise transimpedance amplifier (TIA) f... more This paper presents the design and testing of an ultra-low-noise transimpedance amplifier (TIA) for low-frequency noise measurements on low-impedance (below 1 kΩ) devices, such as advanced IR photodetectors. When dealing with low-impedance devices, the main source of background noise in transimpedance amplifiers comes from the equivalent input voltage noise of the operational amplifier, which is used in a shunt–shunt configuration to obtain a transimpedance stage. In our design, we employ a hybrid operational amplifier in which an input front end based on ultra-low-noise discrete JFET devices is used to minimize this noise contribution. When using IF3602 JFETs for the input stage, the equivalent voltage noise of the hybrid operational amplifier can be as low as 4 nV/√Hz, 2 nV/√Hz, and 0.9 nV/√Hz at 1 Hz, 10 Hz, and 1 kHz, respectively. When testing the current noise of an ideal 1 kΩ resistor, these values correspond to a current noise contribution of the same order as or below that ...

Computational Methods and Experimental Measurements XIII, 2007

This paper presents a system for optoelectronic beam steering of a phase antenna array. The micro... more This paper presents a system for optoelectronic beam steering of a phase antenna array. The microwave signal from an RF generator controlled by a pulse generator is transmitted to the electrical input of an optical elevation control unit, which generates N microwave signals with independent amplitude and phase. The control unit utilizes an optical wave from a laser. All outputs of those control units are connected to inputs of N optical azimuth control units, which provide M linear element antennas control. Those units utilize an optical wave from a second laser. This way an M x N element of a planar antenna control is provided. The presented method is compared with the classical and electronic method, which consists of multi-bits microwave phase shifters for producing an electronic scanning effect. On the basis of this concept we realized 16-element linear antenna array printed on a dielectric substrate fully controlled by an optoelectronic system. A tuned wavelength laser in the range 1520-1600 nm and 10 mW optical output power has been used as an optical signal source. The optical signal is modulated by a microwave signal. The applied modulator operates in the third optical window, allowing optical signal modulation to 10GHz. Very high resolution and an excellent accuracy of the antenna beam positioning can be achieved. The optimal technique depends on the number of antenna elements, which implicates beam width. The presented method is preferred for very narrow antenna beams.

Sensors

This paper’s purpose was to demonstrate a performance of a novel approach in a low-noise optical ... more This paper’s purpose was to demonstrate a performance of a novel approach in a low-noise optical sensor for an FTIR spectrometer. Methods: Compared to the standard FTIR detection setup, our sensor ensures a higher signal-to-noise ratio (SNR) and lower signal standard deviation by reducing the uncorrelated noise components (e.g., thermal and 1/f noises of the detection module). Its construction is based on two-channel detection modules and a processing unit with implemented cross-correlation signal analyses. Each module was built of LWIR HgCdTe photodiodes and low-noise transimpedance amplifiers. Results: the experiments demonstrated a decrease in a signal standard deviation of about 1.7 times with a 10 dB-improvement in the SNR. Conclusion: this result indicates our sensor’s main benefit, especially in registered “weak” and noisy interferograms.

Lasers and Electro-optics

An overview of the important techniques for detection of optical radiation from the ultraviolet, ... more An overview of the important techniques for detection of optical radiation from the ultraviolet, through visible to infrared spectral regions is presented. At the beginning single-point devices are considered. Next, different application circuits used in direct detection systems together with elucidation of the design of front-end circuits and discussion of their performance are presented. Third part of the paper is devoted to advanced techniques including coherent detection. Finally, the updated information devoted to readout of signals from detector arrays and focal plane arrays is included. It is shown that detector focal plane technology has revolutionized many kinds of imaging in the past 25 years.

Bulletin of the Military University of Technology, 2020

The paper presents noise measurements of low-resistance photon detectors with a specially develop... more The paper presents noise measurements of low-resistance photon detectors with a specially developed system. These measurements are significant for many applications. This issue is particularly critical for laser absorption spectroscopy systems to detect trace amounts of gases. In these systems, the detection limit is determined by noise origins, e.g., light source, background, and detector noise and its readout electronics. The use of some specially designed components of the system (low-noise - 3.6 × 10-19 V2/Hz for f >1 kHz) cross-correlation signal processing provides to obtain a measuring floor noise below 10-18 V2/Hz for f > 10 Hz and below 10-19 V2/Hz for f > 1 kHz after ten minutes’ analysis. Measurements of some reference resistors have verified the system’s performance. Finally, the system was also applied to determine the spectral noise density of the II -Type SuperLattice photodetector made of InAs / InAsSb.

Electronics

When performing low-frequency noise measurements on low-impedance electron devices, transformer c... more When performing low-frequency noise measurements on low-impedance electron devices, transformer coupling can be quite effective in reducing the contribution of the equivalent input noise voltage of the preamplifier to the background noise of the system. However, noise measurements on electron devices are usually performed with a biased device under test. A bridge configuration must be used to null the DC component at the input of the transformer. Unfortunately, using a bridge results in a complication of the set-up and degradation of the system’s sensitivity because of the noise introduced by the nulling arm. We propose an alternative approach for blocking the DC component that exploits the fact that supercapacitors with capacitances in excess of a few Farads are nowadays easily available. Actual measurement results in conventional and advanced measurement configurations are discussed that demonstrate the advantages of the approach we propose.

Proceedings IRS² 2011, 2011

the paper describes low noise first stage optical receivers.Analysis of operating conditions affe... more the paper describes low noise first stage optical receivers.Analysis of operating conditions affecting signal-to-noise ratio has been carried out.Each preamplifier was carefully optimised to work with particular type of the detector.

Certain gases in human breath are known to be indicators of the presence of diseases. These gases... more Certain gases in human breath are known to be indicators of the presence of diseases. These gases have been identified as biomarkers using different instruments, mainly based on chemical methods, e.g. gas chromatography or chemiluminescence. The article describes an application one of the most sensitive optoelectronic method-Cavity Enhanced Absorption Spectroscopy (CEAS) to investigation of fractional exhaled nitric oxide (FeNO). Measurement of FeNO concentration is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of NO the vibronic molecular transitions were used in our optoelectronic sensor. The wavelengths of these transitions are situated in the spectral range of 5.23 μm-5.29 μm. A setup of the sensor consists of a pulsed quantum cascade laser (QCL), optical cavity, high sensitivity photoreceiver and a digital signal processing system. The optical cavity was built of spherical mirrors of high reflectance. The leakage optical signal from the cavity output was detected with specially developed low noise detection module. In the sensor, the detection limit of 75 ppb (parts per billion) was obtained.

Proceedings SENSOR 2013, 2013

Certain gases in human breath are known to be indicators of the presence of diseases. These gases... more Certain gases in human breath are known to be indicators of the presence of diseases. These gases have been identified as biomarkers using different instruments, mainly based on chemical methods, e.g. gas chromatography or chemiluminescence. The article describes an application one of the most sensitive optoelectronic method-Cavity Enhanced Absorption Spectroscopy (CEAS) to investigation of fractional exhaled nitric oxide (FeNO). Measurement of FeNO concentration is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of NO the vibronic molecular transitions were used in our optoelectronic sensor. The wavelengths of these transitions are situated in the spectral range of 5.23 μm-5.29 μm. A setup of the sensor consists of a pulsed quantum cascade laser (QCL), optical cavity, high sensitivity photoreceiver and a digital signal processing system. The optical cavity was built of spherical mirrors of high reflectance. The leakage optical signal from the cavity output was detected with specially developed low noise detection module. In the sensor, the detection limit of 75 ppb (parts per billion) was obtained.

The paper presents an overview of a few optoelectronic technologies for gases detection. Two sens... more The paper presents an overview of a few optoelectronic technologies for gases detection. Two sensors of nitrogen oxides (NOx) are also described. In the sensors the cavity enhanced absorption spectroscopy was applied. It is characterized by a very good sensitivity and selectivity of the detection process. The main aspect of its operation bases on absorption of the light by specific compounds. The identification of the matter is determined by spectral matching of the two spectra: optical radiation and absorption lines of species of interest. In contrast to the remote detection methods, the measurements are made at the place of sampling. Polish laser diodes and modern quantum cascade lasers were used there. Laser emission wavelengths were located in the visible (410 nm) and infrared range. The detection limit of ppb level was achieved. Due to that, they can be successfully applied to monitoring of atmospheric pollution, explosives detection and in diseases diagnosis. The preliminary s...

Electronics, 2020

This paper presents the design and testing of a low-noise programmable voltage source. Such a pie... more This paper presents the design and testing of a low-noise programmable voltage source. Such a piece of instrumentation is often required as part of the measurement setup needed to test electronic devices without introducing noise from the power supply (such as photodetectors, resistors or transistors). Although its construction is based on known configurations, here the discussion is focused on the characterization and the minimization of the output noise, especially at very low frequencies. The design relies on a digital-to-analog converter, proper lowpass filters, and a low-noise Junction Field-Effect Transistors (JFET) based voltage follower. Because of the very low level of output noise, in some cases we had to resort to cross-correlation in order to reduce the background noise of the amplifiers used for the characterization of the programmable source. Indeed, when two paralleled IF9030 JFETs are used in the voltage follower, the output noise can be as low as 3 nV/√Hz, 0.6 nV/√H...

Applied Sciences, 2020

High precision and fast measurement of gas concentrations is important for both understanding and... more High precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most perceptive because of their advantages in a specific application. We present the basics of each technique, their performance limits, and the possibility of further development. The practical implementations of representative examples are described in detail. Finally, we present a performance comparison of selected practical application, accumulating data reported over the preceding decade, and conclude from this comparison.

Metrology and Measurement Systems, 2017

The article presents state of work in technology of free-space optical communications (Free Space... more The article presents state of work in technology of free-space optical communications (Free Space Optics − FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.

Proceedings of the 2000 International Conference on Quantitative InfraRed Thermography, 2000

A simple and low cost IR surveillance device based on a single, thermoelectrically cooled detecto... more A simple and low cost IR surveillance device based on a single, thermoelectrically cooled detector working in 3-5 m spectral band is presented. Despite its simplicity, preliminary estimations of its detection range show its sufficient effectiveness in detection of airborne objects seeing abeam or aft.

Proceedings of the 1998 International Conference on Quantitative InfraRed Thermography, 1998

The multiband MBP 98A pyrometer developed for non-contact temperature measurement of objects with... more The multiband MBP 98A pyrometer developed for non-contact temperature measurement of objects with unknown and wavelength-dependent emissivity has been presented in this paper. The pyrometer was designed using single thermoelectrically cooled PbS detector of spectral band of 1-2.5 Ilm and 8 narrow-band optical filters. It enables temperature measurement of objects at temperature within a range of 500°C-1200°C and a speed of 75 Hz. It can be used for controlling various industrial-technological processes as well as in research works for testing of classic singleband pyrometers in temperature measurement of objects whose emissivity depends on the wavelength and time.

Metrology and Measurement Systems, 2016

The paper describes an integrated laser absorption system as a potential tool for breath analysis... more The paper describes an integrated laser absorption system as a potential tool for breath analysis for clinical diagnostics, online therapy monitoring and metabolic disorder control. The sensors operate basing on cavity enhanced spectroscopy and multi-pass spectroscopy supported by wavelength modulation spectroscopy. The aspects concerning selection of operational spectral range and minimization of interference are also discussed. Tests results of the constructed devices collected with reference samples of biomarkers are also presented. The obtained data provide an opportunity to analyse applicability of optoelectronic sensors in medical screening.

Metrology and Measurement Systems, 2016

Sensing technology has been developed for detection of gases in some environmental, industrial, m... more Sensing technology has been developed for detection of gases in some environmental, industrial, medical, and scientific applications. The main tasks of these works is to enhance performance of gas sensors taking into account their different applicability and scenarios of operation. This paper presents the descriptions, comparison and recent progress in some existing gas sensing technologies. Detailed introduction to optical sensing methods is presented. In a general way, other kinds of various sensors, such as catalytic, thermal conductivity, electrochemical, semiconductor and surface acoustic wave ones, are also presented. Furthermore, this paper focuses on performance of the optical method in detecting biomarkers in the exhaled air. There are discussed some examination results of the constructed devices. The devices operated on the basis of enhanced cavity and wavelength modulation spectroscopies. The experimental data used for analyzing applicability of these different sensing te...

Bulletin of the Polish Academy of Sciences Technical Sciences, 2015

The potential of Quantum Cascade Laser technology has been recently harnessed in industry, medici... more The potential of Quantum Cascade Laser technology has been recently harnessed in industry, medicine and military to create a range of original infrared gas sensors. These sensors have opened up many new applications due to compact size, excellent sensitivity, robust construction and low power requirements. They rely on infrared absorption spectroscopy to determine identity and quantity of gases. The measurement of these gases has relied on different technologies including multi-pass spectroscopy, photoacoustic spectroscopy, cavity ring down spectroscopy, and their various modifications. In this review paper some technologies are described in terms of its advantages/disadvantages in many application. The results of own works about methane, ammonia, nitric oxide, nitrous oxide, and carbonyl sulfide detection are presented as well

Computational Methods and Experimental Measurements XIV, 2009

This paper presents opportunities of application of cavity enhanced absorption spectroscopy (CEAS... more This paper presents opportunities of application of cavity enhanced absorption spectroscopy (CEAS) in nitrogen oxide (NO x) detection. The CEAS technique is based on the off-axis arrangement of an optical cavity. In this system, an absorbing gas concentration is determined by measurement of the decay time of a light pulse trapped in an optical cavity. Measurements are not sensitive to laser power fluctuation or photodetector sensitivity fluctuation. In this configuration, the setup includes the resonance optical cavity, build with spherical mirrors of high reflectance. Pulsed lasers are used as the light sources. NO x detection is carried out in the blue and far infrared range. The signal is registered with a newly developed low noise photoreceiver. The features of the designed system show that it is possible to build a portable trace gases sensor. Its sensitivity could be comparable with that of chemical detectors. Such a system has several advantages: relatively low price, small size and weight, low power consumption, and the possibility of the detection of other gases.

Applied Sciences

This paper presents the design and testing of an ultra-low-noise transimpedance amplifier (TIA) f... more This paper presents the design and testing of an ultra-low-noise transimpedance amplifier (TIA) for low-frequency noise measurements on low-impedance (below 1 kΩ) devices, such as advanced IR photodetectors. When dealing with low-impedance devices, the main source of background noise in transimpedance amplifiers comes from the equivalent input voltage noise of the operational amplifier, which is used in a shunt–shunt configuration to obtain a transimpedance stage. In our design, we employ a hybrid operational amplifier in which an input front end based on ultra-low-noise discrete JFET devices is used to minimize this noise contribution. When using IF3602 JFETs for the input stage, the equivalent voltage noise of the hybrid operational amplifier can be as low as 4 nV/√Hz, 2 nV/√Hz, and 0.9 nV/√Hz at 1 Hz, 10 Hz, and 1 kHz, respectively. When testing the current noise of an ideal 1 kΩ resistor, these values correspond to a current noise contribution of the same order as or below that ...

Computational Methods and Experimental Measurements XIII, 2007

This paper presents a system for optoelectronic beam steering of a phase antenna array. The micro... more This paper presents a system for optoelectronic beam steering of a phase antenna array. The microwave signal from an RF generator controlled by a pulse generator is transmitted to the electrical input of an optical elevation control unit, which generates N microwave signals with independent amplitude and phase. The control unit utilizes an optical wave from a laser. All outputs of those control units are connected to inputs of N optical azimuth control units, which provide M linear element antennas control. Those units utilize an optical wave from a second laser. This way an M x N element of a planar antenna control is provided. The presented method is compared with the classical and electronic method, which consists of multi-bits microwave phase shifters for producing an electronic scanning effect. On the basis of this concept we realized 16-element linear antenna array printed on a dielectric substrate fully controlled by an optoelectronic system. A tuned wavelength laser in the range 1520-1600 nm and 10 mW optical output power has been used as an optical signal source. The optical signal is modulated by a microwave signal. The applied modulator operates in the third optical window, allowing optical signal modulation to 10GHz. Very high resolution and an excellent accuracy of the antenna beam positioning can be achieved. The optimal technique depends on the number of antenna elements, which implicates beam width. The presented method is preferred for very narrow antenna beams.

Sensors

This paper’s purpose was to demonstrate a performance of a novel approach in a low-noise optical ... more This paper’s purpose was to demonstrate a performance of a novel approach in a low-noise optical sensor for an FTIR spectrometer. Methods: Compared to the standard FTIR detection setup, our sensor ensures a higher signal-to-noise ratio (SNR) and lower signal standard deviation by reducing the uncorrelated noise components (e.g., thermal and 1/f noises of the detection module). Its construction is based on two-channel detection modules and a processing unit with implemented cross-correlation signal analyses. Each module was built of LWIR HgCdTe photodiodes and low-noise transimpedance amplifiers. Results: the experiments demonstrated a decrease in a signal standard deviation of about 1.7 times with a 10 dB-improvement in the SNR. Conclusion: this result indicates our sensor’s main benefit, especially in registered “weak” and noisy interferograms.

Lasers and Electro-optics

An overview of the important techniques for detection of optical radiation from the ultraviolet, ... more An overview of the important techniques for detection of optical radiation from the ultraviolet, through visible to infrared spectral regions is presented. At the beginning single-point devices are considered. Next, different application circuits used in direct detection systems together with elucidation of the design of front-end circuits and discussion of their performance are presented. Third part of the paper is devoted to advanced techniques including coherent detection. Finally, the updated information devoted to readout of signals from detector arrays and focal plane arrays is included. It is shown that detector focal plane technology has revolutionized many kinds of imaging in the past 25 years.

Bulletin of the Military University of Technology, 2020

The paper presents noise measurements of low-resistance photon detectors with a specially develop... more The paper presents noise measurements of low-resistance photon detectors with a specially developed system. These measurements are significant for many applications. This issue is particularly critical for laser absorption spectroscopy systems to detect trace amounts of gases. In these systems, the detection limit is determined by noise origins, e.g., light source, background, and detector noise and its readout electronics. The use of some specially designed components of the system (low-noise - 3.6 × 10-19 V2/Hz for f >1 kHz) cross-correlation signal processing provides to obtain a measuring floor noise below 10-18 V2/Hz for f > 10 Hz and below 10-19 V2/Hz for f > 1 kHz after ten minutes’ analysis. Measurements of some reference resistors have verified the system’s performance. Finally, the system was also applied to determine the spectral noise density of the II -Type SuperLattice photodetector made of InAs / InAsSb.

Electronics

When performing low-frequency noise measurements on low-impedance electron devices, transformer c... more When performing low-frequency noise measurements on low-impedance electron devices, transformer coupling can be quite effective in reducing the contribution of the equivalent input noise voltage of the preamplifier to the background noise of the system. However, noise measurements on electron devices are usually performed with a biased device under test. A bridge configuration must be used to null the DC component at the input of the transformer. Unfortunately, using a bridge results in a complication of the set-up and degradation of the system’s sensitivity because of the noise introduced by the nulling arm. We propose an alternative approach for blocking the DC component that exploits the fact that supercapacitors with capacitances in excess of a few Farads are nowadays easily available. Actual measurement results in conventional and advanced measurement configurations are discussed that demonstrate the advantages of the approach we propose.

Proceedings IRS² 2011, 2011

the paper describes low noise first stage optical receivers.Analysis of operating conditions affe... more the paper describes low noise first stage optical receivers.Analysis of operating conditions affecting signal-to-noise ratio has been carried out.Each preamplifier was carefully optimised to work with particular type of the detector.

Certain gases in human breath are known to be indicators of the presence of diseases. These gases... more Certain gases in human breath are known to be indicators of the presence of diseases. These gases have been identified as biomarkers using different instruments, mainly based on chemical methods, e.g. gas chromatography or chemiluminescence. The article describes an application one of the most sensitive optoelectronic method-Cavity Enhanced Absorption Spectroscopy (CEAS) to investigation of fractional exhaled nitric oxide (FeNO). Measurement of FeNO concentration is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of NO the vibronic molecular transitions were used in our optoelectronic sensor. The wavelengths of these transitions are situated in the spectral range of 5.23 μm-5.29 μm. A setup of the sensor consists of a pulsed quantum cascade laser (QCL), optical cavity, high sensitivity photoreceiver and a digital signal processing system. The optical cavity was built of spherical mirrors of high reflectance. The leakage optical signal from the cavity output was detected with specially developed low noise detection module. In the sensor, the detection limit of 75 ppb (parts per billion) was obtained.

Proceedings SENSOR 2013, 2013

Certain gases in human breath are known to be indicators of the presence of diseases. These gases... more Certain gases in human breath are known to be indicators of the presence of diseases. These gases have been identified as biomarkers using different instruments, mainly based on chemical methods, e.g. gas chromatography or chemiluminescence. The article describes an application one of the most sensitive optoelectronic method-Cavity Enhanced Absorption Spectroscopy (CEAS) to investigation of fractional exhaled nitric oxide (FeNO). Measurement of FeNO concentration is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of NO the vibronic molecular transitions were used in our optoelectronic sensor. The wavelengths of these transitions are situated in the spectral range of 5.23 μm-5.29 μm. A setup of the sensor consists of a pulsed quantum cascade laser (QCL), optical cavity, high sensitivity photoreceiver and a digital signal processing system. The optical cavity was built of spherical mirrors of high reflectance. The leakage optical signal from the cavity output was detected with specially developed low noise detection module. In the sensor, the detection limit of 75 ppb (parts per billion) was obtained.

The paper presents an overview of a few optoelectronic technologies for gases detection. Two sens... more The paper presents an overview of a few optoelectronic technologies for gases detection. Two sensors of nitrogen oxides (NOx) are also described. In the sensors the cavity enhanced absorption spectroscopy was applied. It is characterized by a very good sensitivity and selectivity of the detection process. The main aspect of its operation bases on absorption of the light by specific compounds. The identification of the matter is determined by spectral matching of the two spectra: optical radiation and absorption lines of species of interest. In contrast to the remote detection methods, the measurements are made at the place of sampling. Polish laser diodes and modern quantum cascade lasers were used there. Laser emission wavelengths were located in the visible (410 nm) and infrared range. The detection limit of ppb level was achieved. Due to that, they can be successfully applied to monitoring of atmospheric pollution, explosives detection and in diseases diagnosis. The preliminary s...

Electronics, 2020

This paper presents the design and testing of a low-noise programmable voltage source. Such a pie... more This paper presents the design and testing of a low-noise programmable voltage source. Such a piece of instrumentation is often required as part of the measurement setup needed to test electronic devices without introducing noise from the power supply (such as photodetectors, resistors or transistors). Although its construction is based on known configurations, here the discussion is focused on the characterization and the minimization of the output noise, especially at very low frequencies. The design relies on a digital-to-analog converter, proper lowpass filters, and a low-noise Junction Field-Effect Transistors (JFET) based voltage follower. Because of the very low level of output noise, in some cases we had to resort to cross-correlation in order to reduce the background noise of the amplifiers used for the characterization of the programmable source. Indeed, when two paralleled IF9030 JFETs are used in the voltage follower, the output noise can be as low as 3 nV/√Hz, 0.6 nV/√H...

Applied Sciences, 2020

High precision and fast measurement of gas concentrations is important for both understanding and... more High precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most perceptive because of their advantages in a specific application. We present the basics of each technique, their performance limits, and the possibility of further development. The practical implementations of representative examples are described in detail. Finally, we present a performance comparison of selected practical application, accumulating data reported over the preceding decade, and conclude from this comparison.

Metrology and Measurement Systems, 2017

The article presents state of work in technology of free-space optical communications (Free Space... more The article presents state of work in technology of free-space optical communications (Free Space Optics − FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.

Proceedings of the 2000 International Conference on Quantitative InfraRed Thermography, 2000

A simple and low cost IR surveillance device based on a single, thermoelectrically cooled detecto... more A simple and low cost IR surveillance device based on a single, thermoelectrically cooled detector working in 3-5 m spectral band is presented. Despite its simplicity, preliminary estimations of its detection range show its sufficient effectiveness in detection of airborne objects seeing abeam or aft.

Proceedings of the 1998 International Conference on Quantitative InfraRed Thermography, 1998

The multiband MBP 98A pyrometer developed for non-contact temperature measurement of objects with... more The multiband MBP 98A pyrometer developed for non-contact temperature measurement of objects with unknown and wavelength-dependent emissivity has been presented in this paper. The pyrometer was designed using single thermoelectrically cooled PbS detector of spectral band of 1-2.5 Ilm and 8 narrow-band optical filters. It enables temperature measurement of objects at temperature within a range of 500°C-1200°C and a speed of 75 Hz. It can be used for controlling various industrial-technological processes as well as in research works for testing of classic singleband pyrometers in temperature measurement of objects whose emissivity depends on the wavelength and time.

Metrology and Measurement Systems, 2016

The paper describes an integrated laser absorption system as a potential tool for breath analysis... more The paper describes an integrated laser absorption system as a potential tool for breath analysis for clinical diagnostics, online therapy monitoring and metabolic disorder control. The sensors operate basing on cavity enhanced spectroscopy and multi-pass spectroscopy supported by wavelength modulation spectroscopy. The aspects concerning selection of operational spectral range and minimization of interference are also discussed. Tests results of the constructed devices collected with reference samples of biomarkers are also presented. The obtained data provide an opportunity to analyse applicability of optoelectronic sensors in medical screening.

Metrology and Measurement Systems, 2016

Sensing technology has been developed for detection of gases in some environmental, industrial, m... more Sensing technology has been developed for detection of gases in some environmental, industrial, medical, and scientific applications. The main tasks of these works is to enhance performance of gas sensors taking into account their different applicability and scenarios of operation. This paper presents the descriptions, comparison and recent progress in some existing gas sensing technologies. Detailed introduction to optical sensing methods is presented. In a general way, other kinds of various sensors, such as catalytic, thermal conductivity, electrochemical, semiconductor and surface acoustic wave ones, are also presented. Furthermore, this paper focuses on performance of the optical method in detecting biomarkers in the exhaled air. There are discussed some examination results of the constructed devices. The devices operated on the basis of enhanced cavity and wavelength modulation spectroscopies. The experimental data used for analyzing applicability of these different sensing te...

Bulletin of the Polish Academy of Sciences Technical Sciences, 2015

The potential of Quantum Cascade Laser technology has been recently harnessed in industry, medici... more The potential of Quantum Cascade Laser technology has been recently harnessed in industry, medicine and military to create a range of original infrared gas sensors. These sensors have opened up many new applications due to compact size, excellent sensitivity, robust construction and low power requirements. They rely on infrared absorption spectroscopy to determine identity and quantity of gases. The measurement of these gases has relied on different technologies including multi-pass spectroscopy, photoacoustic spectroscopy, cavity ring down spectroscopy, and their various modifications. In this review paper some technologies are described in terms of its advantages/disadvantages in many application. The results of own works about methane, ammonia, nitric oxide, nitrous oxide, and carbonyl sulfide detection are presented as well

Computational Methods and Experimental Measurements XIV, 2009

This paper presents opportunities of application of cavity enhanced absorption spectroscopy (CEAS... more This paper presents opportunities of application of cavity enhanced absorption spectroscopy (CEAS) in nitrogen oxide (NO x) detection. The CEAS technique is based on the off-axis arrangement of an optical cavity. In this system, an absorbing gas concentration is determined by measurement of the decay time of a light pulse trapped in an optical cavity. Measurements are not sensitive to laser power fluctuation or photodetector sensitivity fluctuation. In this configuration, the setup includes the resonance optical cavity, build with spherical mirrors of high reflectance. Pulsed lasers are used as the light sources. NO x detection is carried out in the blue and far infrared range. The signal is registered with a newly developed low noise photoreceiver. The features of the designed system show that it is possible to build a portable trace gases sensor. Its sensitivity could be comparable with that of chemical detectors. Such a system has several advantages: relatively low price, small size and weight, low power consumption, and the possibility of the detection of other gases.