Details

Autor(en) / Beteiligte

• Chen, Feifan
• Jiang, Shoulin
• Jin, Wei
• Bao, Haihong
• Ho, Hoi Lut
• Wang, Chao
• Gao, Shoufei

Titel

Ethane detection with mid-infrared hollow-core fiber photothermal spectroscopy

Ist Teil von

• Optics express, 2020-12, Vol.28 (25), p.38115-38126

Ort / Verlag

United States

Erscheinungsjahr

2020

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• We report a compact mid-infrared (MIR) photothermal spectroscopic ethane (C H ) sensor with a hollow-core negative-curvature-fiber (HC-NCF) gas cell. The HC-NCF supports low-loss transmission of an MIR pump (3.348 µm) and a near-infrared (NIR) probe (1.55 µm). The pump and probe laser beams are launched into the gas cell from the opposite ends of the HC-NCF, allowing independent MIR pump delivery and NIR fiber-optic probe circuitry. The use of Fabry-Perot as the probe interferometer simplifies the sensor design and suppresses the common-mode noise in the lead in/out single-mode fiber. With a 14-cm-long HC-NCF, an ethane sensor system with the limit of detection (LOD) of 13 parts-per-billion (ppb) is achieved with 1 s lock-in time constant. The LOD goes down to 2.6 ppb with 410 s average time, which corresponds to noise equivalent absorption (NEA) of 2.0×10 and is a record for the hollow-core fiber MIR gas sensors. The system instability is 2.2% over a period of 8 hours.