There is disclosed a system and associated method for mounting an optical component in an optical arrangement. An optical component (1) is provided having a circular edge region (5). A mount (9) having a circular wall is also provided, the circular wall being configured for radially-spaced cooperation with the circular edge region of the optical component. The system is configured such that one of said circular edge region (5) and said circular wall (17) has a plurality of spaced-apart protrusions (23) provided around it. The other of the circular edge region (5) and the circular wall (17) has a plurality of spaced-apart recesses provided around it. The protrusions (23) and the recesses (7) are configured such that each protrusion (23) may be aligned with a respective recess (7) and engaged within said recess (7) via relative rotation between the optical component (1) and the mount (9). The system further includes an adhesive (32) for application between said circular edge region (5) and said circular wall (17) to adhesively fix the optical component (1) in position relative to the mount (9).