Fig. 1. Overall structure of airborne laser communication optical terminal

Fig. 2. Schematic diagram of the optical path in the airborne laser communication optical terminal

Fig. 3. Geometric model schematic of the optical window and definition of viewing angles

Fig. 4. Calculation domain size and boundary settings

Fig. 5. Schematic diagram of mesh division

Fig. 6. Schematic diagram of ray tracing

Fig. 7. Ray tracing schematic cloud map

Fig. 8. Influence of optical grid density on \begin{document}${OPD}_{RMS}$\end{document} and \begin{document}$ {OPD}_{PV} $\end{document}

Fig. 9. Influence of ray tracing distance on \begin{document}${OPD}_{RMS}$\end{document} for two windows at different AZ angles

Fig. 10. \begin{document}${OPD}_{RMS}$\end{document} comparison of two windows at different AZ angles for ray tracing distance of 6R

Fig. 11. \begin{document}${OPD}_{RMS}$\end{document} comparison of two windows at different EL angles

Fig. 12. \begin{document}${OPD}_{RMS}$\end{document} variation of two windows at different flight altitudes and speeds

Fig. 13. Far-field diffraction intensity distribution map

Fig. 14. Curves of intensity difference and offset with AZ angle variation

Fig. 15. Curves of intensity difference and offset variation with flight altitude and speed