摘要 |
A reflective afocal beam expander optical system is disclosed for transmitting electromagnetic (EM) energy. The beam expander, in the preferred embodiment, is comprised of a reflective afocal system including a section of a primary parabolic mirror, a section of a secondary parabolic mirror, and a beam splitter. The two mirrors have a common axis of rotational symmetry and a common focus point and the centerline of the incoming EM energy is displaced from the axis of rotational symmetry. The beam splitter is positioned with respect to the primary mirror to receive the edge rays of the EM energy and cause the EM energy to be folded and exit through a window while clearing all optical elements. A viewing system having a viewing axis through the beamsplitter allows a viewer to see through the same window as the exiting EM energy. A second refractive afocal optical system is made integral to the specific laser system being used in order to control beam expansion ratios. |