Sensitive methane detection based on quartz-enhanced photoacoustic spectroscopy with a high-power diode laser and wavelet filtering

•A high power diode laser was used as excitation source for CH4 detection.•30.72 kHz quartz tuning fork was used as an acoustic wave transducer.•A micro-resonator and water vapor were added to enhance the signal level.•Wavelet filtering was adopted to improve the SNR of the CH4-QEPAS sensor.