Transducer-matched multipulse excitation for signal-to-noise ratio improvement in diode laser-based photoacoustic systems.

We analyze transducer-matched multipulse excitation as a method for improving of the signal-to-noise ratio (SNR) for diode laser-based photoacoustic systems. We discuss the principle of the technique, its advantages, and potential drawbacks and perform measurements to analyze the obtainable SNR increase. We show in experiment and computationally that a lower boundary estimate of 1.2 to 1.8 fold SNR improvement can be provided using transducer-matched pulse bursts, depending on the transducer and particular arrangement. Finally, we analyze implications that the transducer resonance effects may have on the recently introduced advanced photoacoustic techniques. The findings are of immediate interest to modalities utilizing dense pulse sequences and systems possessing limited pulse energy. In particular, transducer-matched multipulse excitation may be beneficial for diode-based photoacoustic systems operated with transducers in the range of 1 to 5 MHz since the required hardware is readily available.