Loading...
Please wait, while we are loading the content...
Similar Documents
Dual-feedback mid-infrared cavity-enhanced absorption spectroscopy for H2CO detection using a radio-frequency electrically-modulated interband cascade laser.
| Content Provider | Semantic Scholar |
|---|---|
| Author | He, Qixin Zheng, Chuantao Lou, Minhan Ye, Weilin Wang, Yiding Tittel, Frank K. |
| Copyright Year | 2018 |
| Abstract | A mid-infrared cavity-enhanced sensor system was demonstrated for the detection of formaldehyde (H2CO) using a continuous-wave (cw) interband cascade laser (ICL) centered at 3599 nm. A compact Fabry-Perot (F-P) cavity with a physical size of 38 × 52 × 76 mm3 was developed consisting of two concave mirrors with a radius of curvature of 80 mm and a reflectivity of 99.8% at 3.6 μm. Different from the widely reported electro-optical (EO) external modulation based Pound-Drever-Hall (PDH) locking technique, a radio-frequency electrical internal modulation based PDH technique was used for locking the laser mode to the cavity mode. A dual-feedback control on the laser current and on the piezo transducer (PZT) displacement was utilized for further stabilizing mode locking. A 20 m effective optical path length was achieved with a cavity length of 2 cm and a finesse of 1572. The effectiveness and sensitivity of the sensor system were demonstrated by targeting an absorption line at 2778.5 cm-1 for H2CO measurements. A linear relation between the cavity transmitted signal amplitude and the H2CO concentration was obtained within the range of 0-5 ppm. A 1σ detection limit of 25 parts-per-billion (ppb) was achieved with an averaging time of 1 s based on Allan-Werle variance analysis. The reported dual-feedback RF modulation based PDH technique led to a method for gas detection using a similar experimental setup and measurement scheme. |
| Starting Page | 15436 |
| Ending Page | 15444 |
| Page Count | 9 |
| File Format | PDF HTM / HTML |
| DOI | 10.1364/OE.26.015436 |
| PubMed reference number | 30114805 |
| Journal | Medline |
| Volume Number | 26 |
| Issue Number | 12 |
| Alternate Webpage(s) | https://scholarship.rice.edu/bitstream/handle/1911/102711/oe-26-12-15436.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://cpb-us-e1.wpmucdn.com/blogs.rice.edu/dist/8/3316/files/2018/06/dual-feedback-mid-infrared-5-29-18-1xdjez0.pdf |
| Alternate Webpage(s) | https://doi.org/10.1364/OE.26.015436 |
| Journal | Optics express |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
