Is laser surgery a proper noun?

No, the compound noun 'laser surgery' is a common noun, a general Word for a type of medical procedure.

A proper noun is the name of a specific person, place, or thing; for example:

• Paul C. Ajamian OD, American Board of Optometry
• Laser Spine Institute, Philadelphia, PA
• Alma Lasers Legato II (for treatment of scars)