System and method for tissue treatment

A system comprising:

• an optical element configured to receive an electromagnetic radiation (EMR), and focus the EMR along an optical axis to a focal region in a target tissue;
• a controller configured to direct the optical element along a first scan path, wherein a motion of the optical element along the first scan path is configured to traverse the focal region along a treatment path in the target tissue;
• a cooling element down-beam from the optical element and configured to be removably attached to the system via three or more datums and to receive the focusing EMR, the cooling element comprising:
• a first window comprising a first proximal surface and a first distal surface;
• a second window down-beam from the first window, the second window comprising a second proximal surface and a second distal surface, wherein the second window is configured to contact the target tissue or a tissue adjacent to the target tissue via the second distal surface, and wherein the first scan path is parallel to the second distal surface within 50 milliradians;
• a coolant chamber located between the first distal surface of the first window and the second proximal surface of the second window and configured to receive a coolant.