Laser eye surgery system

A laser eye surgery system comprising:

• an eye interface device configured to interface with an eye of a patient;
• an objective lens;
• a scanning assembly configured to support the objective lens and the eye interface device and to scan a focal point of a laser beam to different target locations within the eye in x, y and z orthogonal directions;
• a laser beam source configured to generate the laser beam for performing the laser eye surgery;
• wherein the scanning assembly, the objective lens and the eye interface device are configured to rest together on the eye, to freely move together relative to the laser beam source in the x, y and z directions and to follow together a corresponding free movement of the patient in the x, y and z directions;
• a free-floating mechanism that supports the scanning assembly and is configured to accommodate the free movement of the scanning assembly relative to the laser beam source in a manner that maintains alignment in the x, y and z directions between the laser beam and the target locations during the free movement, the free-floating mechanism including first and second beam deflection devices configured to slide relative to one another in at least the z direction to vary a distance in the z direction between the first and second beam deflection devices, the first and second beam deflection devices being external to the scanning assembly and located on an optical path between the laser beam source and the scanning assembly, the first beam deflection device arranged to receive the laser beam in a first direction and deflect it to a second direction, and the second beam deflection device arranged to receive the laser beam in the second direction and deflect it to a third direction, wherein the second direction is the z direction, and the first and third directions are the x or y direction, the second beam deflection device arranged to receive a reflection of a portion of the laser beam from the focal point location propagating in a direction opposite to the third direction and deflect it to a direction opposite to the second direction, the first beam deflection device being disposed to receive the portion of the electromagnetic radiation beam propagating in the direction opposite to the second direction and deflect it to a direction opposite to the first direction;
• and
• a detection assembly configured to generate an intensity signal indicative of intensity of the reflection of the portion of the laser beam.