Hello everyone, i am simulating a Michelson interferometer, where one mirror is slightly tilted, see picture.. This results in circular arcs / hyperbolic cross-section fringes. The center of these fringes depends on the focal length i am using, see picture. Is there an analytical expression for the center of these fringes in dependency of the focal lenght? Are there books that show the closed-form expression for such hyperbolic fringes / Fizeau fringes (so far i haven't found anything in the common literature). Would be great if anyone has some insights on this. Thanks!