Filtering characteristics of a three-lens slit spatial filter for high-power lasers

Aiming for a three-lens slit spatial filtering system with excellent performances in inhibition of pinhole closure, improvement of beam quality, compactness of the system, and lowering the requirement of vacuum, the filtering characteristics and image relay of the slit spatial filter are demonstrated. The results show that the beam quality is greatly improved, and the system has a good property in image relay, which has potential applications in high-power lasers.