Recent developments in the applications of mid-infrared lasers, LEDs, and other solid state sources to gas detection

Smith, S. D.; Hardaway, H. R.; Crowder, John Graham

doi:10.1117/12.467944

Cited by 19 publications

(9 citation statements)

References 19 publications

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“…their spectral emission is relatively high (eg 2 mW per steradian in a FWHM bandwidth of 0.17 μm at 4.2 μm [86] ) and the cost is low ($1-2 [86] ).…”

Section: Light Sources For Ndirmentioning

confidence: 99%

“…Page 24 Figure 19. Typical temperature dependence of LED spectral emission, taken from [86]. The peak wavelength is strongly wavelengthdependent, and emitted power falls at higher temperatures.…”

Section: 0mmmentioning

confidence: 99%

“…Here, a 50% duty cycle has 3.7x higher RMS emitted power, whereas a 0.5% duty cycle has 5.8x better power efficiency. [86] . Much of the cited work exploited a phenomenon known as negative luminescence (NL) [ 116 ] .…”

Section: 0mmmentioning

confidence: 99%

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Optical gas sensing: a review

Hodgkinson

Tatam

2012

Meas. Sci. Technol.

1,267

841

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The detection and measurement of gas concentrations using the characteristic optical absorption of the gas species is important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change. This article reviews the field, covering several individual gas detection techniques including non-dispersive infrared (NDIR), spectrophotometry, tunable diode laser spectroscopy and photoacoustic spectroscopy. We present the basis for each technique, recent developments in methods and performance limitations. The technology available to support this field, in terms of key components such as light sources and gas cells, has advanced rapidly in recent years and we discuss these new developments. Finally, we present a performance comparison of different techniques, taking data reported over the preceding decade, and draw conclusions from this benchmarking.

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“…their spectral emission is relatively high (eg 2 mW per steradian in a FWHM bandwidth of 0.17 μm at 4.2 μm [86] ) and the cost is low ($1-2 [86] ).…”

Section: Light Sources For Ndirmentioning

confidence: 99%

Section: 0mmmentioning

confidence: 99%

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Optical gas sensing: a review

Hodgkinson

Tatam

2012

Meas. Sci. Technol.

1,267

841

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“…These sensors are low cost, having few components (typically a simple microbulb light source, gold coated reflective light path and detector) [5]. The microbulbs used in conventional NDIR sensors have two main advantages; their spectral emission is relatively high (2 mW per steradian in a FWHM bandwidth of 0.17 μm at 4.2 μm, for one example [6]) and the cost is low ($1-2 [6]). A key to the miniaturisation of this technology has been the integration of multiple detectors and filters into a small single package, typically a 9mm diameter TO-5 can [7].…”

Section: Introductionmentioning

confidence: 99%

Non-dispersive infra-red (NDIR) measurement of carbon dioxide at 4.2μm in a compact and optically efficient sensor

Hodgkinson

Smith²,

Ho³

et al. 2013

Sensors and Actuators B: Chemical

167

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Non-dispersive infra-red (NDIR) gas detection has enjoyed widespread uptake as a result of development of devices in the standard miniature format for gas sensors, consisting of a cylinder with external dimensions of 20 mm diameter x 16.5 mm height. We present a new design for such a sensor, making use of low-cost injection moulding technology. The design pays particular attention to the problem of maintaining a high optical throughput while providing an acceptable optical pathlength for gas detection. A detailed analysis of the design is presented, with the results of optical raytracing, showing a raytrace estimate for 4% of the total emitted radiation reaching each of two separated detector elements and a pathlength of 32 mm. Finally, we show experimental results obtained with as-manufactured devices, with a short-term limit of detection for carbon dioxide (CO 2 ) estimated at 1 ppm or a noise equivalent absorption (NEA) of 3 x 10 -5 AU. Highlights New design of non-dispersive infra-red (NDIR) sensor for CO 2 and other gases  Standard miniature format for gas sensors -a cylinder 20mm D x 16.5mm H  Raytrace -estimated 32mm pathlength  Manufactured in volume using gold-coated injection-moulded reflective optics  Short-term limit of detection 1ppm CO 2 , noise equivalent absorbance 3x10 -5 AU

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“…Typically, these emitter sources consist of a double-coiled filament made of tungsten that is manufactured using a laborious semiautomated fabrication process [3]. Incandescent micro light bulbs offer a high spectral emission [18], but the IR transmission through the glass envelope drops significantly for wavelengths larger than 4.5 µm. Therefore, their application for gas detection systems using the mid and far infrared wavelength range is not ideal.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of an infrared emitter using a generic integration platform based on wire bonding

Schröder

Rödjegård

Fischer

et al. 2016

J. Micromech. Microeng.

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Abstract. This paper reports a novel approach for the fabrication of infrared (IR) emitters for non-dispersive infrared gas sensing. The proposed concept enables the integration of superior resistive heater materials with microelectromechanical systems (MEMS) structures. In this study, non-bondable filaments made of nickel chromium are attached to mechanical attachment structures using a fully automated state-of-the-art wire bonder. The formation of the electrical contacts between the integrated filaments and the electrical contact pattern on the substrate is performed using conventional gold stud bumping technology. The placement accuracy of the integrated filaments is evaluated using white-light interferometry, while the contact formation using stud bumping to embed the filaments is investigated using focus ion beam milled crosssections. A proof-of-concept IR emitter has been successfully operated and heated up to 960• C in continuous mode for 3 hours.Wire bonding, integration platform, stud bumping, MEMS, MEMS-based infrared emitter, NDIR, gas sensing, non-bondable materials, nickel-chromium wire, NiCr filament, Nikrothal wire, resistive heating, joule heating:

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Recent developments in the applications of mid-infrared lasers, LEDs, and other solid state sources to gas detection

Cited by 19 publications

References 19 publications

Optical gas sensing: a review

Optical gas sensing: a review

Non-dispersive infra-red (NDIR) measurement of carbon dioxide at 4.2μm in a compact and optically efficient sensor

Fabrication of an infrared emitter using a generic integration platform based on wire bonding

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