Photoacoustic property of Gallium-based liquid metals measured with intensity modulated high repetition supercontinuum laser

Gallium-based liquid metals (LMs), including elemental gallium and associated alloy metals, are notable for their liquid state at room temperature. These LMs have gained attention due to their safety, non-toxicity, and exceptional physical and chemical properties. They exhibit optical resonance in the UV-VIS-IR spectral range, making them potential alternatives to expensive precious metals like gold and silver. However, the optical properties of gallium-based LMs have not been fully explored, especially their photoacoustic property. Photoacoustic detection is a label free method based on photoacoustic effect, detecting the optical absorption contrast of samples through photoacoustic waves. Photoacoustic detection has the advantages of non-contact, highs sensitivity, good contrast and etc. Using the photoacoustic detection method, we can avoid the influence of light scattering on the metal surface and thus obtain the optical absorption of gallium-based LMs directly. In this paper, we report a photoacoustic detection system based on intensity modulated high repetition supercontinuum laser to explore the light absorption properties of EGaIn LM.