Fig. 1. Graph of prism incidence surface. (a) Incidence surface of orthogonal double Porro prism; (b) simplified incident surface of Porro prism

Fig. 2. Schematic of passive double Porro mirror resonator

Fig. 3. Illustration of light transmission in Porro prism

Fig. 4. Output spot patterns of passive double Porro resonator under different prism widths. (a) 5 μm; (b) 12 μm; (c) 18 μm; (d) 22 μm

Fig. 5. Spot amplitude pattern of passive double Porro resonator with prism width of 22 μm

Fig. 6. Output spot patterns of passive double Porro resonator under different angle errors. (a) δ=0.6″; (b) δ=1″; (c) δ=2″; (d) δ=3″

Fig. 7. Simulation diagrams of output spot of passive double Porro resonator under different angle errors. (a) δ1=2″,δ2=3″; (b) δ1=2″, δ2=4″; (c) δ1=2″, δ2=5″

Fig. 8. Simulation diagram of output spot of resonator at δ=8″