Fig. 3: Real-time PA detection of SO2 and CO2 using the proposed gas-filled fiber Raman laser consisting of two synthesized mid-IR spectral lines. | Nature Communications

Fig. 3: Real-time PA detection of SO2 and CO2 using the proposed gas-filled fiber Raman laser consisting of two synthesized mid-IR spectral lines.

From: Synthesizing gas-filled anti-resonant hollow-core fiber Raman lines enables access to the molecular fingerprint region

Fig. 3: Real-time PA detection of SO2 and CO2 using the proposed gas-filled fiber Raman laser consisting of two synthesized mid-IR spectral lines.

a Raw data stream output from the lock-in amplifier, containing the PA signal excited from both CO2 and SO2 with varied concentrations as a function of time. Inset: a zoom-in result of a.b PA signals of CO2 and SO2 extracted in real-time from a.c Real-time PA signal recorded for varied CO2 concentration while constant SO2 concentration at 84 ppm. d,e are linear fits of the PA intensity versus gas concentrations at different repetition rates of 1.00 and 942 kHz, respectively. f The monitoring of PA intensity excited from 1.3 ppm CO2 by increasing the temperature of acoustic chamber from 22 °C to 23.5 °C, using the Raman spectral line at 4.25 μm but with two different repetition rates of 942 Hz and 1 kHz, respectively.

Back to article page