The ultraviolet nanosecond laser surface treatment of carbon fiber-reinforced polymer was studied to optimize surface morphology and enhance bonding strength. The samples were treated with various laser powers and pulse frequencies

and the effects were evaluated using contact angle measurements

surface energy analysis

and mechanical testing. The synergistic mechanisms of photochemical and photothermal effects were revealed

and the influence of energy density on surface morphology was analyzed. The results show that an appropriate energy density (160–203 mJ/cm

2

) effectively removes epoxy resin

exposes intact carbon fiber surfaces

and significantly improves surface

energy and wettability. The water contact angle decreases from 82.7° to 69.7°

and the single lap shear strength increases from 23.6 MPa to 26.7 MPa

with an improvement of 13.1%. However

energy density exceeding 235 mJ/cm

2

leads to carbon fiber breakage

reducing mechanical performance. This study demonstrates the effectiveness of ultraviolet nanosecond laser treatment in enhancing sample bonding performance

offering an efficient surface treatment solution for applications in aerospace and other demanding fields.