Application Of Quantum Cascade Lasers Research Articles

MP17-15 INFRARED-(IR)-IMAGING CLASSIFIES PROSTATE CANCER LABEL-FREE: A PROSPECTIVE IR-PROSPECT-STUDY SHOWS POTENTIAL FOR CLINICAL APPLICATION AND RESEARCH

You have accessJournal of UrologyCME1 Apr 2023MP17-15 INFRARED-(IR)-IMAGING CLASSIFIES PROSTATE CANCER LABEL-FREE: A PROSPECTIVE IR-PROSPECT-STUDY SHOWS POTENTIAL FOR CLINICAL APPLICATION AND RESEARCH Henning Bahlburg, Claus Kuepper, Frederik Grosserueschkamp, Nina Goertzen, Carlo Sternemann, Sebastian Berg, Karl Tully, Axel Mosig, Rein-Jueri Palisaar, Andrea Tannapfel, Klaus Gerwert, Joachim Noldus, and Florian Roghmann Henning BahlburgHenning Bahlburg More articles by this author , Claus KuepperClaus Kuepper More articles by this author , Frederik GrosserueschkampFrederik Grosserueschkamp More articles by this author , Nina GoertzenNina Goertzen More articles by this author , Carlo SternemannCarlo Sternemann More articles by this author , Sebastian BergSebastian Berg More articles by this author , Karl TullyKarl Tully More articles by this author , Axel MosigAxel Mosig More articles by this author , Rein-Jueri PalisaarRein-Jueri Palisaar More articles by this author , Andrea TannapfelAndrea Tannapfel More articles by this author , Klaus GerwertKlaus Gerwert More articles by this author , Joachim NoldusJoachim Noldus More articles by this author , and Florian RoghmannFlorian Roghmann More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003237.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The Goal of this study was to evaluate whether artificial intelligence (AI) is suited to classify prostate cancer (PCa) label-free. In the last decade, IR-microscopy was able to showcase its potential to classify different tissues and pathologies in several studies. Recorded IR-Spectra reflect the biochemical status of the examined cell. The application of quantum-cascade lasers as source of light has accelerated data acquisition and thus enabled integration into clinical research pathways METHODS: In this study, tissue from 258 patients was investigated. Initially, AI with Random Forrest (RF) algorithm was applied. Prostatic tissue showed to be morphologically more demanding than expected. As the study population increased, a robust deep-learning AI was implemented. RESULTS: Deep-learning AI reached an AUC of 0.96 with a sensitivity of ∼98% and a specificity of ∼83% when classifying PCa label-free. This marks an improvement compared to RF, which showed a sensitivity of 82% and a specificity of 69%. CONCLUSIONS: AI-based IR-Imaging detects PCa with a sensitivity of 98%. Further improvement may be achieved by additional training and increase in sample size. Subsequently, laser-assisted micro-dissection may allow precise and homogenous sampling for detailed molecular analysis of tumor tissues. Results may be used to train AI in the detection of molecular tumor characteristics such as oncological targets. Source of Funding: This project was funded by the Ministry of Culture and Research of the Federal State of Northrine Westphalia © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e218 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Henning Bahlburg More articles by this author Claus Kuepper More articles by this author Frederik Grosserueschkamp More articles by this author Nina Goertzen More articles by this author Carlo Sternemann More articles by this author Sebastian Berg More articles by this author Karl Tully More articles by this author Axel Mosig More articles by this author Rein-Jueri Palisaar More articles by this author Andrea Tannapfel More articles by this author Klaus Gerwert More articles by this author Joachim Noldus More articles by this author Florian Roghmann More articles by this author Expand All Advertisement PDF downloadLoading ...

MOVPE Technology of Fe-Compensated In PLayers for the Quantum Cascade Laser Applications

MOVPE Technology of Fe-Compensated In PLayers for the Quantum Cascade Laser Applications

Comprehensive growth and characterization study on highly n-doped InGaAs as a contact layer for quantum cascade laser applications

We present growth and characterization studies of highly n-doped InGaAs epilayers on InP substrate by metal organic vapor phase epitaxy to use as an n-contact layer in quantum cascade laser applications. We have introduced quasi two-dimensional electrons between 10 s pulsed growth n-doped InGaAs epilayers to improve both carrier concentration and mobility of structure by applying pulsed growth and doping methods towards increasing the Si dopant concentration in InGaAs. Additionally, the V/III ratio optimization under fixed group III source flow has been investigated with this new method to understand the effects on both crystalline quality and electrical properties of n-InGaAs epilayers. Finally, we have obtained high crystalline quality of n-InGaAs epilayers grown by 10 s pulsed as a contact layer with 2.8 × 1019 cm−3 carrier concentration and 1530 cm2 V−1 s−1 mobility.

Study of intersubband transitions in GaN-ZnGeN2 coupled quantum wells

In this work, we design and analyze a closely lattice-matched wide bandgap GaN-ZnGeN2 coupled quantum well (QW) structure targeting for near-infrared (IR) (λ ≤ 3 um) intersubband transition for quantum cascade laser applications. The coupled quantum well structure comprised two GaN wells separated by a thin ZnGeN2 barrier layer. The QW active region is surrounded by thick ZnGeN2 layers as barriers. The computations of the electron-phonon and electron-photon scattering rates are carried out by employing the Fermi's golden rule for transitions. The calculation takes into consideration the conservation of energy and momentum in scattering processes. The coupled QW structure is optimized through tuning the confined subband energy levels in the conduction band to achieve (1) electron-LO phonon resonant scattering when the energy separation between the first and second conduction subband levels matches the phonon energy of GaN (92 meV); and (2) dominant electron-photon transition in near-IR between the third and second conduction subband levels.

LP-MOVPE growth and properties of high Si-doped InGaAs contact layer for quantum cascade laser applications

AbstractThe work presents doping characteristics and properties of high Si−doped InGaAs epilayers lattice−matched to InP grown by low pressure metal−organic vapour phase epitaxy. Silane and disilane were used as dopant sources. The main task of investigations was to obtain heavily doped InGaAs epilayers suitable for usage as plasmon−confinement layers in the construction of mid−infrared InAlAs/InGaAs/InP quantum−cascade lasers (QCLs). It requires the doping concentration of 1×10

Technology and properties of low-pressure metalorganic vapour phase epitaxy grown InGaAs/AlInAs superlattice for quantum cascade laser applications

Technology and properties of low-pressure metalorganic vapour phase epitaxy grown InGaAs/AlInAs superlattice for quantum cascade laser applications

Formation of coupled-cavities in quantum cascade lasers using focused ion beam milling

Focused ion beam (FIB) systems have become very useful tools used in the nanotechnology because they provide easy prototyping or post-processing customization of individual devices. A practical application of such post-processing is modification of monolithic quantum cascade laser (QCL) to obtain the structure with coupled cavities (CC-QCL), enabling its single mode performance, critical in many QCL applications. In-situ electrical measurements of the test structures showed that the main problem is avoiding a secondary deposition of the milled material. The redeposition can significantly reduce the performance and reliability of lasers. An avoidance of FIB imaging after final FIB cleaning of walls was revealed as an important factor leading to high quality of structures. The paper describes the solution by developing appropriate patterning procedure. This enabled the formation of exemplary single mode CC-QCLs with excellent performance at 9.45μm wavelength with 30dB side-mode suppression ratio, operating at room temperature. Performance of obtained single-mode coupled cavity quantum cascade lasers was stable, repeatable and no reliability problems were observed.

Application of quantum cascade lasers to trace gas detection

Abstract 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

Beam combining of quantum cascade lasers for remote sensing

Abstract This letter highlights the application of quantum cascade lasers for stand-off detection and remote sensing. In particular, we review the topic of power scaling via beam combining architectures and conclude with remarks on generating axial symmetric irradiance profiles via incoherent aperture beam combining of individual quantum cascade lasers.

High Resolution Terahertz Spectroscopy with Quantum Cascade Lasers

High resolution terahertz (THz) spectroscopy is a powerful analytical tool for laboratory purposes as well as for remote sensing in astronomy, planetary research, and Earth observation. THz quantum cascade lasers (QCLs) are promising sources for implementation into THz spectrometers, in particular at frequencies above 3 THz, which is the least explored portion of the THz region. One application of QCLs in THz spectroscopy is in absorption spectrometers, where they can replace less powerful and somewhat cumbersome sources based on frequency mixing with gas lasers. Another one is using a QCL as local oscillator in a heterodyne spectrometer for remote sensing. This article will review the state-of-the art in high resolution THz spectroscopy with QCLs.

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

O were selected.Our two channel sensor is designated for simultaneous detection of both compounds. Each channel consists ofsinglemodequantumcascadelaser,opticalcavity,andaphotodetectionmodule. Thelaserswerepreciselytunedto the wavelength of interest. Optical cavities were built with spherical mirrors of high reflectance. The signalsfromthecavitiesoutputswereregisteredwithspeciallydevelopedlownoisedetectionmodules.PACS:07.07.Df,42.25.Dd,42.55.Px,42.60.Da,42.62.Fi

Application of quantum cascade lasers to high-precision atmospheric trace gas measurements

We review our recent results in development of high-precision laser spectroscopic instrumentation using midinfrared quantum cascade lasers (QCLs). Some of these instruments have been directed at measurements of atmospheric trace gases where a fractional precision of 10−3 or better of ambient concentration may be required. Such high precision is needed in measurements of fluxes of stable atmospheric gases and measurements of isotopic ratios. Instruments that are based on thermoelectrically cooled midinfrared QCLs and thermoelectrically cooled detectors have been demonstrated that meet the requirements of high-precision atmospheric measurements, without the need for cryogens. We also describe the design of and results from a new dual QCL instrument with a 200-m path-length absorption cell. This instrument has demonstrated 1-s noise of 32 ppt for formaldehyde (HCHO) and 9 ppt for carbonyl sulfide (OCS).

Use of quantum cascade lasers for detection of explosives: progress and challenges

Detection of explosives is an emerging task for maintaining civil security. Optical methods and especially tunable diode laser spec- troscopy are discussed as means for providing fast and reliable data. Selective and sensitive detection is possible in the midinfrared spectral region; however, until recently, small and easy to operate laser sources were not readily available for applications outside the laboratory. The situation changes with the maturation of quantum cascade lasers (QCLs). We present detection methods based on photofragmentation and sub- sequent midinfrared detection of the fragments for the detection of nitrogen-based explosives. For this type of explosive, the very low va- por pressure makes the use of direct spectroscopic techniques ex- tremely difficult, since the equilibrium concentrations are in the ppb to ppt range. Peroxide-based explosives like triacetone triperoxide possess a much higher vapor pressure, making direct absorption spectroscopy and also a quartz-enhanced photoacoustic spectroscopy sensor possi- ble. The progress and challenges of the application of QCLs, also with respect to interferences with other molecules present, are discussed.

Quantum cascade laser absorption spectroscopy as a plasma diagnostic tool: an overview.

The recent availability of thermoelectrically cooled pulsed and continuous wave quantum and inter-band cascade lasers in the mid-infrared spectral region has led to significant improvements and new developments in chemical sensing techniques using in-situ laser absorption spectroscopy for plasma diagnostic purposes. The aim of this article is therefore two-fold: (i) to summarize the challenges which arise in the application of quantum cascade lasers in such environments, and, (ii) to provide an overview of recent spectroscopic results (encompassing cavity enhanced methods) obtained in different kinds of plasma used in both research and industry.

Optical characterization of intersubband transitions in ZnxCd1‐xSe/Znx′Cdy′Mg1‐x′‐y′Se asymmetric coupled quantum well structures by contactless electroreflectance

AbstractContactless electroreflectance (CER) was used to characterize the possible optical transitions in a ZnxCd1‐xSe/Znx′Cdy′Mg1‐x′‐y′Se asymmetric coupled quantum well (ACQW) structure grown by molecular beam epitaxy for quantum cascade laser (QCL) applications. CER spectrum revealed a wide range of the possible optical transitions in ACQW structure. The ground state transition was assigned by comparing with the photoluminescence emission signal taken from the same structure. A comprehensive analysis of the CER spectrum led to the identification of various interband transitions. The intersubband transitions were estimated and confirmed by FTIR measurements. The results demonstrate the potential of using CER as a complimentary technique for the contactless and nondestructive characterization of the wide band gap II‐VI ACQW structures for QCL applications (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Quantum cascade laser absorption spectroscopy – A new method to study molecular plasma components

The recent development of quantum cascade lasers (QCLs) offers an attractive new option for the monitoring and control of industrial plasma processes and for trace-gas analysis as well as for highly time-resolved studies on the kinetics of plasma processes. The contribution reviews selected examples of the application of QCLs for infrared absorption studies in basic research and for plasma monitoring and control in industry.

Quantum cascade lasers in chemical physics

In the short space of 15 years since their first demonstration, quantum cascade lasers have become the most useful sources of tunable mid-infrared laser radiation. This Letter describes these developments in laser technology and the burgeoning applications of quantum cascade lasers to infrared spectroscopy. We foresee the potential application of quantum cascade lasers in other areas of chemical physics such as research on helium droplets, in population pumping, and in matrix isolation infrared photochemistry.

Application of quantum cascade lasers and infrared-fibres for the monitoring and control of industrial plasma processes

Quantum cascade lasers (QCL) offer attractive options for the application of mid-infrared absorption spectroscopy for industrial process monitoring and control. In particular the in-situ measurement of reactive plasma compounds can give new insight into the reaction kinetics of industrial plasma processes. For these purposes the compact quantum cascade laser measurement and control system (Q-MACS) has been combined with an infrared-fibre to allow a flexible and completely dust-sealed incoupling of the infrared radiation into the reactor chamber of an industrial plasma surface modification system. The system has been completed with a fast and compact detector and a data acquisition system to monitor concentrations of species of interest in the plasma process online. First tests proofed the potential of this approach.

Applications of quantum cascade lasers for sensitive trace gas measurements of CO, CH4, N2O and HCHO

AbstractWe describe here a sensitive quantum cascade laser absorption spectrometer (QCLAS) employed for aircraft based measurements during the GABRIEL 2005 and HOOVER 2006 and 2007 campaigns. This 3-channel instrument measures CO, HCHO, CH4 and N2O using a 64-m path double corner cube White cell. Performance of the instrument was examined for the four species and precisions for CO, N2O and CH4 were measured in the field to be 0.5, 0.5 and 0.7% respectively (2σ). The 1σ detection limit for HCHO was ∼500 pptv for a 2 s average, while signal averaging of the HCHO over a 2 min time interval resulted in a 150 pptv detection limit with a duty cycle of 60%.

Application of quantum cascade lasers in studies of low-pressure plasmas: Characterization of rapid passage effects on density and temperature measurements

The application of quantum cascade lasers in the intrapulse operation mode for low-pressure plasma spectroscopy is hampered by the observation of rapid passage effects, leading to lower quantitative accuracy. We demonstrate that accurate densities and rotational temperatures of CH4 within a CH4 plasma can be obtained by characterizing the rapid passage effects in gas phase conditions prior to carrying out the plasma measurements. Furthermore, we show that the ratios of the integrated absorption of two transitions are not affected by the rapid passage effect and, thus, rotational temperatures of species can be obtained.