Contrast-enhanced nonlinear photoacoustic microscopy at 1.7 μm enabled by a high-power gain-switched laser

We present a contrast-enhanced Grueneisen-relaxation photoacoustic microscopy (GR-PAM) by a home-made high-power thulium-doped fiber laser (TDFL) at 1725 nm. The images of carbon fiber and artery plaque show a significant signal-to-noise (SNR) improvement (over 16dB).