Investigation of UR90 outputting annular beam for a chemical oxygen-iodine laser

Abstract

In this paper, we mainly describe the structure of an unstable resonator with 90-deg beam rotation(UR9O) outputting annular beam for a chemical oxygen iodine laser(COIL) and the geometry mode of the beam. A beam quality of 3.2 times diffraction limit was achieved in the experiment while the COIL average output power was approximately 4kw in the case ofmagnification of 1.69, as well as the property ofthe annular beam was analyzed.