Use of phase corrector plates to increase the power of radially polarized oscillators

High-power oscillation was achieved with radial or azimuthal polarization at 480 W and M2=5.4 using pump chambers that induced 0.3λ of balanced spherical aberration. Measurement of wavefront inside the resonator showed that the oscillating mode could flip the sign of the aberration in order to preserve itself in a round trip. Analysis showed that the lasing mode, which has a two-ring structure, is the lowest-order radially polarized mode of the resonator. Spherical aberration correction was employed and allowed the resonator performance to be significantly improved to 600 W at M2=3.5.