Performance characteristics of a passively locked cavity-enhanced absorption spectrometer with wideband-tunable multimode near-infrared light source
| Autor: | Takeshi Imamura, Ryuta Someya, Tetsushi Okamoto, Shigeru Yamaguchi, Naoko Toyoshima, Kazuyoku Tei, Hiroshi Hatano |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Tunable diode laser absorption spectroscopy
Materials science Spectrometer Absorption spectroscopy business.industry General Engineering General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology Laser 01 natural sciences law.invention 010309 optics Wavelength Optics Band-pass filter law Attenuation coefficient 0103 physical sciences 0210 nano-technology business Diode |
| Zdroj: | Japanese Journal of Applied Physics. 55:032401 |
| ISSN: | 1347-4065 0021-4922 |
| DOI: | 10.7567/jjap.55.032401 |
| Popis: | A trace material detection system was developed on the basis of cavity-enhanced absorption spectroscopy (CEAS) using a fiber-coupled passively locked external cavity diode laser (PLEC-DL) in the near-infrared (NIR) wavelength region. The oscillation range of an antireflection-coated diode laser (AR-DL) coupled into an external cavity could be simply selected with a narrowband bandpass filter (1 nm), resulting in a stable wavelength oscillation in the wideband tunability between 1640 and 1680 nm. The external cavity acts as a trace material sensor that exhibits excellent flexibility because it is free from the DL source and is carefully designed with mirrors having reflectivities of ca. 99.995 and 99.99%. Trace-level detection was successfully demonstrated with the developed sensor having a minimum detectable absorption coefficient of 2.4 × 10−8 cm−1, which corresponds to 0.15 ppm for CH4 concentration without interference from H2O absorption lines under atmospheric pressure. |
| Databáze: | OpenAIRE |
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