Hollow waveguide enhanced dimethyl sulfide sensor based on a 3.3μm interband cascade laser

• Published in: Sensors and actuators. B, Chemical Chemical, 2018-02, Vol.255, p.3550-3557
• Main Authors: Li, Jinyi, Luo, Gang, Du, Zhenhui, Ma, Yiwen
• Format: Article
• Language: English
• Subjects: Dimethyl sulfide sensor; Hollow waveguide; Interband cascade laser (ICL); Wavelength modulation spectroscopy (WMS)
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.09.190

•A compact and low-power dimethyl sulfide (DMS) laser sensor system was designed and evaluated for the first time.•The sensor system consists of a 3367nm interband cascade laser (ICL) and a 5m hollow waveguide (HWG).•The HWG enables the laser sensor with a high sensitivity of 20ppbv and a rapid rise time of ∼27s and fall time of ∼25s.•A measurement precision of 21ppbv was achieved with time resolution of 1s.•A minimum detection limit of ∼2.8ppbv was achieved with an averaging time of 125s. Detection of dimethyl sulfide (CH3SCH3) is significant for protection of environmental atmosphere and safety of industrial and agricultural production. A tunable laser absorption spectroscopy (TLAS)-based dimethyl sulfide sensor, employing a 5m hollow waveguide (HWG) as a gas cell and a 3.37μm, continuous-wave, DFB, room temperature interband cascade laser (ICL), is reported. Wavelength modulation spectroscopy second harmonic normalized by the first harmonic (WMS 2f/1f) technique is used to retrieve the concentration of dimethyl sulfide with high sensitivity. The sensor has a mass of ∼5kg and consumes ∼50W of electrical power. The sensor performance evaluation shows that it has a sensitivity of 20ppb with time resolution of 1s, a rapid rise time and fall time of ∼27s and ∼25s and a measurement precision of 21ppb. Furthermore, an Allan deviation analysis shows that the detection limit can reach 2.8ppb for a 125s averaging time. Overall, the reported sensor can be applied to environmental monitoring, industrial production and the biomedicine field for dimethyl sulfide detection.