A surgical device based on the concept of controlling the laser power during laser surgery based on optical and other signals from the tip and the tissue is described. A laser surgical system generally comprises several basic components, such as a laser, a delivery system, a tip and a control system. A tip may be considered as a particular case of a thermo-optical tip (TOT). TOT is an optical and mechanical element which could be used to modify or treat soft and hard tissues, including cutting, coagulation, vaporization, carbonization, and ablation of tissues.