Optical assembly for polarization rotation

An optical assembly (28) is used for polarization rotation of the incident linearly polarized input light (3a) and for generating linearly polarized emergent light output (3b). The assembly (28) is designed so that a polarization of the input light (3a) is rotated by a polarization rotation angle which is greater than 10 °. At least one p-mirror (M2) is arranged for the reflection of p-polarized incident light so that the incident p-polarized light at an incident angle (α) which differs by at least 10 ° by a 45 ° angle. The result is an optical assembly which provides a linearly polarized output light having a predetermined polarization direction with the smallest possible flow losses.