Fiber Optic Beam Homogenizer and Resonator Design for 5-kW Class Supersonic Chemical Oxygen-Iodine Laser (COIL)

摘要

The Chemical Oxygen- Iodine Laser (COIL) beam of 5.3 kW average power was homogenized by transmitting through a low-loss fiber optic with a rectangular core. The fiber optic integrator transformed the beam into a beam with a uniform illumination. The exit aperture of the fiber was then imaged by projection optics and the beam uniformity was analyzed in the image plane. These experiments demonstrated a simple technique of providing a highly uniform beam over a large target area by using the low loss fiber. The desired rectangular beam footprints were achieved without the use of an external aperture. The beam profiles and power were recorded and analyzed before and after the fiber. The COIL used for this purpose was specially configured for a stable resonator to produce a near-square cross section, low divergence, and multimode beam.