Standoff detection of explosives and chemical agents using broadly tuned external-cavity quantum cascade lasers (EC-QCLs)

Takeuchi, Eric B.; Rayner, Timothy J.; Weida, Miles J.; Crivello, S.; Day, Timothy

doi:10.1117/12.768932

Cited by 7 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They achieved an uncertainty of 3.1% and normalized sensitivity of 3.3 ppm•m Hz −1/2 for N 2 O and 9.3% and normalized sensitivity of 30 ppm•m Hz −1/2 for CH 4 at a standoff range of 45 m [123]. Moreover, QCLs have been widely used for standoff explosives detection [124][125][126]. In realistic scenarios, explosives are usually concealed, and their detection mostly relies on the sensing of evaporated substance in the surrounding air.…”

Section: Tdlas With Non-cooperative Targetmentioning

confidence: 99%

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

et al. 2020

Remote Sensing

View full text Add to dashboard Cite

Remote chemical detection in the atmosphere or some specific space has always been of great interest in many applications for environmental protection and safety. Laser absorption spectroscopy (LAS) is a highly desirable technology, benefiting from high measurement sensitivity, improved spectral selectivity or resolution, fast response and capability of good spatial resolution, multi-species and standoff detection with a non-cooperative target. Numerous LAS-based standoff detection techniques have seen rapid development recently and are reviewed herein, including differential absorption LiDAR, tunable laser absorption spectroscopy, laser photoacoustic spectroscopy, dual comb spectroscopy, laser heterodyne radiometry and active coherent laser absorption spectroscopy. An update of the current status of these various methods is presented, covering their principles, system compositions, features, developments and applications for standoff chemical detection over the last decade. In addition, a performance comparison together with the challenges and opportunities analysis is presented that describes the broad LAS-based techniques within the framework of remote sensing research and their directions of development for meeting potential practical use.

show abstract

Section: Tdlas With Non-cooperative Targetmentioning

confidence: 99%

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

et al. 2020

Remote Sensing

View full text Add to dashboard Cite

show abstract

“…In the medium infra-red (MIR) range, using the mature InP-based QCL technology, the output power reaches now 5 Watts with a wall plug efficiency (WPE) above 20% for QCLs emitting at 4.6µm in continuous wave (CW) at room temperature (RT) [1]. Actually, the QCL development effort is driven by various applications such as greenhouse gas sensing, warfare chemical agents detection and healthcare monitoring [2][3][4]. MIR emitting QCLs are also well suited for recent defense system developments including directed infrared countermeasures (DIRCM) devices [5].…”

Section: Introductionmentioning

confidence: 99%

32 emitters quantum cascade laser phased array

et al. 2012

View full text Add to dashboard Cite

We demonstrate a monolithic Quantum Cascade Laser array. We show phase-locking and single-mode emission at λ=8.4µm. It consists of narrow ridges buried into InP:Fe. Phase-locking is provided by evanescent coupling between adjacent ridges. This µ-structuration is simultaneously an answer to the excessive heating and poor beam quality of broad area lasers. First, it increases the surface of exchange between the multi-layer active region and the InP:Fe, which presents a higher thermal conductivity. Secondly, by choosing carefully the width of emitters and the distance between them, we insure phase locking and control of the supermode emission. We have investigated 2µm wide emitters. In order to study the behavior of evanescent coupling, we have chosen spacing from 1 to 8 microns. The number of emitters ranges from 1 to 64. Technological feasibility was demonstrated up to 64 emitters, and lasing operation up to 32 emitters. We have obtained a pure dual-lobe far-field pattern as expected from an anti-symmetrical supermode. The width of each lobes narrows with an increasing array size as expected from the diffraction theory. The beam quality is insensitive to the injective current. The optical power scales linearly with the number of emitters.

show abstract

“…Compactness and efficiency of QCLs determine the variety of their applications in medicine [1], environmental monitoring [2,3] and monitoring of technological processes [4,5,6]. Developments are also underway for the use of QCLs in biomedicine [7,8], defense and security [6,9], and secure free-space optical communication, primarily in the mid-IR atmospheric transparency windows [10,11,12].…”

Section: Introductionmentioning

confidence: 99%

High-power quantum cascade lasers for 8 μm spectral range

Dudelev,

Cherotchenko,

Vrubel

et al. 2024

Semiconductor Lasers and Laser Dynamics XI

View full text Add to dashboard Cite

We present a study of high-power quantum-cascade lasers (QCL) for 8 μm spectral range with active regions of latticematched to InP substrate and strain-balanced designs. The use of the strained quantum well/barrier pairs made it possible to increase the energy barrier between the upper laser level and continuum by ~ 200 meV. Our experiments show that utilization of the strain-balanced design of the active region makes it possible to more than double the characteristic temperature T0 to 253 K from 125 K for the lattice-matched design. In pulsed mode, QCLs with strain-balanced active region demonstrated high efficiency of 12% and high output optical power of 21 W (over 10 W per facet). This is the highest value of the optical power demonstrated to date in 8 μm spectral region to the best of our knowledge.

show abstract

Standoff detection of explosives and chemical agents using broadly tuned external-cavity quantum cascade lasers (EC-QCLs)

Cited by 7 publications

References 0 publications

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

32 emitters quantum cascade laser phased array

High-power quantum cascade lasers for 8 μm spectral range

Contact Info

Product

Resources

About