Position effects of acoustic micro-resonator in quartz enhanced photoacoustic spectroscopy

The impact of acoustic micro-resonator (AmR) positions with respect to quartz tuning fork on signal amplitude, Q-factor and signal-to-noise ratio (SNR) of the quartz enhanced photoacoustic spectroscopy spectrophone was investigated. The replacement of the result plots’ abscissas makes the highest signal amplitude and the lowest Q-factor for different AmRs appear at the two absolute positions, respectively. These positions are independent on the AmR geometrical parameters, which facilitates the assembly of the spectrophone. The noncoincidence between the positions of the two extreme values results in a flat peak of the SNR curve, which is different from previously reported results. The spectrophone designs for three different applications are discussed in detail.