Thin-disk laser resonator design: The dioptric power variation of thin-disk and the beam quality factor

This paper investigates the general limitations of thin-disk laser (TDL) resonators due to the dioptric power variation of thin-disk (TD) crystal to attain the good beam quality. For this reason, the generalized formulation of TDL resonator in geometric optics theory is analytically derived. The analytical model is developed by considering two general configurations of stable resonators based on the position of the TD crystal inside the resonator; end-disk and fold-disk resonators. The calculation results reveal best M2 factor at operation pump power (OPP) from a specified disk is proportional to the variation interval of the dioptric power of the TD and it depends on the general configuration of resonator. For each configuration, the initial radius of curvature of the TD determines the resonator shape to attain the minimum acceptable M2 factor.