Investigation of gas detection based on fiber laser intracavity absorption spectroscopy

Fiber laser intracavity gas sensor has advantages of high sensitivity and wide wavelength coverage. We present our recent research progress on intracavity gas sensor including the modular structure design and the general procedure of signal processing. The methods of wavelength-sweep-based multiline averaging and attenuator-based cavity loss increment are used to enhance the gas sensor´s stability and sensitivity respectively. The standard deviation of acetylene concentration measurement is reduced by half using the proposed enhancement method and the improved intracavity concentration sensitivity is about 60 times larger than the single-pass external-cavity sensitivity.