A5035790123- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Laser Design and Applications
- Photonic and Optical Devices
- Advanced Chemical Sensor Technologies
- Analytical Chemistry and Sensors
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Gas Sensing Nanomaterials and Sensors
- Advanced Fiber Optic Sensors
- Mass Spectrometry Techniques and Applications
- Catalysis and Hydrodesulfurization Studies
- Catalytic Processes in Materials Science
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- thermodynamics and calorimetric analyses
- Electrochemical Analysis and Applications
- Infrared Target Detection Methodologies
- Spectroscopy and Quantum Chemical Studies
- CCD and CMOS Imaging Sensors
- Advanced MEMS and NEMS Technologies
- Solid State Laser Technologies
TU Wien
2013-2025
University of Applied Sciences Technikum Wien
2019-2023
Supply Chain Competence Center (Germany)
2023
A compact gas sensor system based on quartz-enhanced photoacoustic spectroscopy (QEPAS) employing a continuous wave (CW) distributed feedback quantum cascade laser (DFB-QCL) operating at 4.59 µm was developed for detection of carbon disulfide (CS2) in air trace concentration. The influence water vapor monitored QEPAS signal investigated to enable compensation this dependence by independent moisture sensing. 1 σ limit 28 parts per billion volume (ppbv) s lock-in amplifier time constant...
In this work, a highly sensitive, selective, and industrially compatible gas sensor prototype is presented. The utilizes three distributed-feedback quantum cascade lasers (DFB-QCLs), employing wavelength modulation spectroscopy (WMS) for the detection of hydrogen sulfide (H2S), methane (CH4), methyl mercaptan (CH3SH), carbonyl (COS) in spectral regions 8.0 µm, 7.5 4.9 respectively. addition, field-programmable gate array (FPGA) hardware used real-time signal generation, laser driving,...
An optical cavity can be utilized as an excellent transducer for highly sensitive gas detection with the application of photothermal spectroscopy, featuring beneficial property ultra-low absorption volume within a rugged sensing element. We report novel implementation balanced in Fabry-Perot interferometry via two identical 1 mm-spaced cavities. That way, excess noise limiting sensitivity previous cavity-based sensors was effectively rejected close to fundamental limit shot noise. A quantum...
We report on a comparison between two optical detection techniques, one based Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) module, where quartz tuning fork is acoustically coupled with pair of millimeter-sized resonator tubes; and the other Photothermal (PTS) module Fabry-Perot interferometer acts as transducer to probe refractive index variations. When resonant absorption modulated light occurs in gas sample, QEPAS directly detects acoustic waves while PTS probes variations caused by...
Guiding of highly charged ions through tilted capillaries promises to develop into a tool efficiently collimate and focus low-energy ion beams sub-micrometer spot size. One control parameter optimize guiding is the residual electrical conductivity insulating material. Its strong, nearly exponential temperature dependence key transmission can be used suppress instabilities arising from flux fluctuations incident which otherwise would lead Coulomb blocking capillary. We demonstrate strong...
The implementation of a sensitive and selective as well industrial fit gas sensor prototype based on wavelength modulation spectroscopy with second harmonic detection (2f-WMS) employing an 8-μm continuous-wave distributed feedback quantum cascade laser (CW-DFB-QCL) for monitoring hydrogen sulfide (H2S) at sub-ppm levels is reported. Regarding the applicability analytical process purposes aimed petrochemical environments, synthetic methane (CH4) matrix up to 1000 ppmv together varying H2S...
Trace gas detection was performed by the principle of photothermal interferometry using a Fabry-Perot interferometer combined with wavelength modulation and second harmonic detection. The sensor employed compact, low-volume cell in an overall robust set-up without use any moveable part. A quantum cascade laser used as powerful mid-infrared excitation source to induce refractive index changes sample, whereas near-infrared diode served probe monitor photo-induced variations. functional...
The interferometric cavity-assisted photothermal spectroscopy (ICAPS) method has been proven highly suitable for sensitive and compact gas detection by application of an optical cavity as transducer spectroscopy. This work reports on the implementation overall fiber-coupled probe laser configuration detecting reflectance individual interferometers in a balanced-detection ICAPS system. layout greatly improves sensor system robustness. Two identical 1 mm path length cavities were used balanced...
The ubiquitous trend toward miniaturized sensing systems demands novel concepts for compact and versatile spectroscopic tools. Conventional optical setups include a light source, an analyte interaction region, separate external detector. We present sensor providing room-temperature operation of monolithic surface-active lasers detectors integrated on the same chip. differentiation between emitter detector is eliminated, which enables mutual commutation. Proof-of-principle gas measurements...
We present a compact vertically emitting ring interband cascade laser (ICL) with low power consumption and the possibility for seamless integration into various CO2 sensing applications. Our devices exhibit desirable performance characteristics in battery-driven handheld devices, including room temperature (20 °C) threshold currents as 15 mA, small footprints, stable single-mode emission, suitable rapid isotope-resolved detection. Through epi-down bonding sub-micron accuracy, we achieved...
We report on key developments made in advancing Interferometric Cavity-Assisted Photothermal Spectroscopy (ICAPS) toward a method for rugged and cost-effective gas sensing. In ICAPS, Fabry Perot Interferometer (FPI) is employed to transduce absorption induced analyte specific refractive index changes occurring inside the interferometer. Periodic excitation achieved by modulation of laser’s wavelength photothermal signal detected measuring intensity probe laser reflected FPI. Maximum...
This work reports on the implementation of a fiber-array with attached microlenses in balanced-detection Interferometric Cavity-Assisted Photothermal Spectroscopy (ICAPS) scheme, enabling highly compact probe laser beam path. The sample and reference were coupled into 1-mm spaced Fabry-Perot interferometer parallel separation only 1.25 mm. A quantum cascade was used to induce photo-thermal waves, which detected via beam. realize balanced detection, allowing for significant noise reduction....
The sensitivity of quartz-enhanced photoacoustic spectroscopy (QEPAS) can be drastically increased using the power enhancement in high-finesse cavities. Here, low noise resonant to 6.3 W was achieved a linear Brewster window cavity by exploiting optical feedback locking quantum cascade laser. high intracavity intensity up 73 mm-2 between prongs custom tuning fork resulted strong saturation CO at 4.59 µm. Saturated absorption is discussed theoretically and experimentally for measurements...
The development of a sensitive SO2 QEPAS-based sensor platform employing CW DFB-QCL will be reported. A detection sensitivity 100 ppbv was achieved with 1-sec averaging time for the 1380.94 cm−1 line.
Spectral beam combination of multiple single mode laser sources employing narrowband spectral filters which are arranged on the perimeter regular polygons is demonstrated in order to co-align and co-propagate individual beams. Spectroscopic applicability displayed by spatial filtering, mode-matching subsequent coupling combined beams into a 76 m astigmatic mirror multipass cell.
Spectral beam combination of multiple single mode laser sources employing narrowband spectral filters which are arranged on the perimeter regular polygons is demonstrated. With this simple geometric design, co-alignment and co-propagation individual beams can be reasonably achieved. Spectroscopic applicability displayed by spatial filtering, mode-matching, subsequent coupling combined into a 76 m astigmatic mirror multipass cell.
This work reports on the implementation of a fiber-array with attached microlenses in Balanced-Detection Interferometric Cavity-Assisted Photothermal Spectroscopy (BICAPS) scheme, enabling highly compact probe laser beam path. The sample and reference were coupled into 1-mm spaced Fabry-Pérot interferometer lateral separation only 1.25 mm. A Quantum Cascade Laser was used to induce photo-thermal waves, which detected via beam. realize balanced detection, allowing for significant noise...
Hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and carbonyl (COS) gas detection based on second harmonic wavelength modulation spectroscopy (2f-WMS) using three frequency multiplexed continuous wave quantum cascade lasers (cw QCLs) tunable is presented.
The development of a sensitive SO2 QEPAS based sensor platform employing 140 mW CW-DFB-QCL will be reported. A detection limit 75 ppbv (3σ) was achieved with 1-sec averaging time for the 1380.94 cm−1 absorption line.
We report on the detection of nitric oxide using an Interferometric Cavity-Assisted Photothermal Spectroscopy (ICAPS) gas sensor in combination with a DFB-QCL emitting at 1900 cm<sup>-1</sup> as excitation source. In ICAPS, probe laser is coupled to Fabry-Perot interferometer acting optical transducer thermal effects. A wavelength modulation approach diode was employed, actively lock its point highest sensitivity and linearity interferometric fringe for stable readout. normalized noise...