This paper presents a detailed investigation of the Bessel–Gauss mode in an axicon-based thin-disk resonator utilizing the self-consistency equations. The results show that Bessel–Gauss modes are eigenmodes of it even if the active medium is deformed. Then, both the numerical and the analytical results are consistent. The effects of the active medium deformation and the radius of curvature of the output mirror on the resonator’s behavior have been investigated. In addition, the self-consistency equations have been derived
