Light-controlled flexible tunable grating-based absorption spectroscopy for gas detection

Based on absorption spectroscopy, a spectrum measurement method utilizing light-controlled tunable grating (LTG) is presented for detecting combustible and explosive gases. When the broadband light with gas spectral absorption information is incident on the LTG, the pitch of the LTG is changed continuously under the illumination of controlled driving light. By analyzing diffraction light from the LTG, the information of the absorption spectrum can be obtained, thereby achieving the detection of the target gas. Owing to the usage of optical drive grating, a wavelength scanning over a wide range can be realized without any involvement of electronic components. For practical application, our proposal measurement method was utilized for methane detection, and the corresponding results demonstrate the effectiveness of our method.