Ellipsoidal reflector fixing mechanism, optical measurement system and photoetching equipment

The invention provides an ellipsoidal reflector fixing mechanism which comprises a guide table, a rotating table and a pre-tightening structure, the guide table comprises at least three sliding grooves distributed in the circumferential direction, and centering rods are arranged on the sliding grooves in a sliding mode; the rotating table is arranged on the guide table and comprises arc-shaped grooves corresponding to the sliding grooves in a one-to-one mode, and the centering rods penetrate through the corresponding arc-shaped grooves and then stretch into the light through holes of the ellipsoidal reflector. When the rotating table is rotated, the centering rods slide in the sliding grooves and the arc-shaped grooves at the same time until the centering rods abut against the inner walls of the light through hole, self-adaptive centering of the ellipsoid reflector is achieved, and therefore the size relation between the optical axis of the ellipsoid reflector and the ellipsoid reflector fixing mechanism is a