Fig. 1. Schematic diagram of the modeled cavity. EM, end mirror; QR, 90° polarization rotating quartz rotator; P1 and P2: passes 1 and 2.

Fig. 2. Finite-element method analysis: (a) model geometry, (b) temperature distribution, (c) distribution of the first principal stress magnitude, and (d) principal stresses magnitude and direction with first principal stress in red, second principal stress in green and third principal stress in blue. Only half of the laser slab is simulated due to symmetry.

Fig. 3. Simulation results for depolarization loss at 1060 nm with linear polarization propagating through a two-amplifier head cavity (as shown in Figure 1) without any compensation mechanism.

Fig. 4. Simulation results for depolarization loss at 1060 nm with a quartz rotator placed between the two amplifiers and cut at a thickness to rotate the central wavelength’s polarization by 90°.

Fig. 5. Simulation results for depolarization loss at 1060 nm with a quartz rotator placed inside of both the two amplifiers and cut at a thickness to rotate the central wavelength’s polarization by 90°.

Fig. 6. Wavelength dependence of depolarization losses as a function of beam width for wavelengths ranging from 1045 to 1075 nm at 15 mrad multiplexing angle. (a) Both heads contain a right-handed QR. (b) Opposite-handed QRs in the two heads.

Fig. 7. Wavelength dependence of depolarization as a function of beam width for wavelengths ranging from 1045 to 1075 nm at a 30 mrad multiplexing angle. (a) Both heads contain a right-handed QR. (b) Opposite-handed QRs in the two heads. (c) Same case as (b) with additional uniform waveplates for compensation.