Abstract

Trace-level ammonia gas in air was analyzed using a fiber-based compact cavity ring-down spectrometer (CRDS). For the compact spectrometer, a 20 cm linear cavity with two high reflectivity (${\gt}{99.999}\%$) mirrors was employed. The laser frequency was locked to the cavity resonance by using frequency shifted (160 MHz) optical feedback. For ${{\rm{NH}}_3}$ detection, a strong absorption band at 1513.98 nm with an absorption cross section of ${{3}.{3\cdot1}}{{{0}}^{- 21}}\;{\rm{cm}}/{\rm{molecule}}$ was used. As a result, a detection sensitivity of ${\sim}{0.1}\;{\rm{ppb}}$ (${{3 {\text -}}}\sigma$) was achieved for ${{\rm{NH}}_3}$ within 10 s.

© 2023 Optica Publishing Group

Ultrasensitive, real-time trace gas detection using a high-power, multimode diode laser and cavity ringdown spectroscopy

Andreas Karpf, Yuhao Qiao, and Gottipaty N. Rao
Appl. Opt. 55(16) 4497-4504 (2016)

Optical-feedback cavity ring-down spectroscopy for NO₂ extinction coefficient measurement using a continuous wave laser diode

Chonghui Cheng, Sumei Liu, Haiyang Qi, Pengbing Hu, Pei Ye, and Sunqiang Pan
Appl. Opt. 61(9) 2230-2236 (2022)

Sensor using a photo-acoustic absorption cell with two perpendicular acoustic resonators to analyze multiple molecules

Ismail Bayrakli, Hatice Akman, and Filiz Sari
Appl. Opt. 62(25) 6689-6696 (2023)

Spectroscopic investigation of methylated amines by a cavity-ringdown-based spectrometer

Dilyan Marinov, Julien M. Rey, Michel G. Müller, and Markus W. Sigrist
Appl. Opt. 46(19) 3981-3986 (2007)

Development of a multiple gas analyzer using cavity ringdown spectroscopy for use in advanced fire detection

Eric A. Fallows, Thomas G. Cleary, and J. Houston Miller
Appl. Opt. 48(4) 695-703 (2009)