The objective of this Ph.D. thesis is to improve the bonding region performance of carbon fiber/polyether ether ketone (CF/PEEK) composites using nanosecond pulsed IR-Yb (infrared ytterbium) fiber laser surface treatment. The effects of varying the laser process parameters on the surface, microstructural and mechanical properties of the CF/PEEK composite structure in the joint area are revealed and discussed. The surfaces of CF/PEEK produced by the hot-pressing method, which is widely used in the aerospace industry, were subjected to IR-Yb laser surface pretreatment prior to bonding with the adhesive film. The effect produced by the laser on the surface can be controlled by the value of the released energy, which varies with the laser parameters, including the average power, scanning speed, and frequency. In this study, the effect of changing these laser parameters on the CF/PEEK composite surface was revealed using SEM images, and the appropriate working ranges of the laser parameters were determined for the optimum energy value required to selectively remove the PEEK matrix from the surface without damaging the carbon fiber. Once the working ranges of the laser parameters were determined to obtain the desired surface finishes in the study, single lap shear (SLS), Charpy impact, and double cantilever beam (DCB) tests were performed on the prepared specimens to investigate the effects of the laser parameters on the mechanical strength of the bonded CF/PEEK structures and compared to untreated specimens. An improvement in the mechanical properties of the specimens whose joint surfaces were treated with appropriate laser parameters was achieved. This increase was explained by the values of surface roughness parameters and contact angle measurements..