An apparatus for positioning at least one adjustable mirror in optical systems such as laser scanning systems. The optical systems could be LiDAR systems or OCT systems or any other suitable systems. The apparatus comprises at least one adjustable mirror configured to enable laser light from a laser light source to be incident on the at least one adjustable mirror and to enable at least some of the laser light reflected by the at least one adjustable mirror to be used for scanning of a sample. The apparatus also comprises at least one image sensor and one or more optical components configured to guide, at least some, laser light reflected by the at least one adjustable mirror towards the at least one image sensor. This enables images obtained by the at least one image sensor to provide an indication of a position of the at least one adjustable mirror. This can enable an existing component of the optical system to be used to determine the position of the adjustable mirror.