Fig. 1. Schematic of a chemical oxygen–iodine laser.

Fig. 2. Schematic of nozzle and cavity geometry.

Fig. 3. Microscale and macroscale computational domains.

Fig. 4. Schematic of the microscale computation processed and converted into inflow boundary conditions for the macroscale computational domains.

Fig. 5. Unstable resonator configuration with multiple macroscale computational domains showing the gain sheet approach.

Fig. 6. Schematic of the entire/marching computational domains.

Fig. 7. The predicted Mach number distributions at a plane normal to the optical axis.

Fig. 8. The predicted density distributions at a plane normal to the optical axis.

Fig. 9. The predicted density distributions at a plane normal to the optical axis.

Fig. 10. The predicted excited atom iodine mass fraction distributions at a plane normal to the optical axis.

Fig. 11. The predicted output power convergence history.

Fig. 12. The far-field intensity profile (beam quality ).

Fig. 13. Comparison of the near-field intensity profiles at different gain sheets with four gain sheet calculations.

Fig. 14. Comparison of mass density profiles without/with lasing.

Fig. 15. The predicted pressure distributions at a plane parallel to the optical axis.

Fig. 16. Comparison of excited atom iodine mass fraction distributions without/with lasing.