OAM-dependent transmission and photothermal effects with Talbot enhancement in water and biological tissue

We report an experimental study on the interaction of optical vortex (OV) beams with water and biological tissues, highlighting their potential for photonics--based biomedical applications. By varying the topological charge or orbital angular momentum (OAM) of the OV beam, we observe that higher-order vortex beams exhibit improved transmission through turbid media and induce stronger photothermal responses in pork tissue. The results demonstrate a clear order-dependent relationship between beam structure and light--tissue interaction. Moreover, we investigate the enhancement of heat generation in pork samples using the vortex beam in combination with the Talbot pattern. An increase in temperature of 0.44 o C for l = 0 and 1.02 o C for l = 3 was observed. The results show a significant improvement in heating efficiency when the Talbot pattern is employed. Although the temperature rise depends on the characteristics and thickness of the pork tissue, a consistently higher temperature increase was observed for optical vortex beams with higher OAM orders when combined with the Talbot effect, compared with lower-order or Gaussian illumination under the investigated conditions. These findings not only provide fundamental insights into the propagation of structured light in scattering media but also suggest new opportunities for enhancing laser therapy, photothermal treatment, and deep-tissue biomedical imaging.