High-precision method for disorder in beam tracing in an optical system with elastic optics

Disorder in beam tracing should be calculated accurately when designing an optical system. In conventional numerical calculation methods for the disordered beam path, the optics were treated as rigid bodies and the misalignment caused by the deformation of the optics was neglected. In this work, the expression for the deformation of the surface normal was derived based on the elastic body assumption using differential geometry and the transient response finite-element method. Furthermore, with the aid of this expression, concrete steps for a numerical calculation method for disorder in beam tracing were given. Then, the validity of this improved method was tested with two examples and with an experimental result from another study.