Influence of femtosecond laser beam polarization on cutting thick-walled Nitinol tubing

Femtosecond lasers have become a core technology in medical device manufacturing, particularly for the precise cutting of delicate geometries of devices like Nitinol hypotubes, clot retrievers and stents. The key features of femtosecond laser cutting are extremely low heat input and dross free cutting of all metals, including Nitinol. When considering the femtosecond laser for cutting thicker materials beyond 400 µm, the challenge has been achieving a cutting speed and quality which provides sufficient production rates, especially when compared to “classic” fusion laser cutting.

Laser beam polarization is well known to influence both cutting speed and edge quality in fusion laser cutting. In this work, we investigated the effect of polarization states when processing 500 µm thick Nitinol tubing. A comparison between circular and radial polarization was completed and determined that manipulating polarization has significant effect on the roughness of the laser cut surface and processing speed.