Photoablation

Photoablation is the use of light or lasers to destroy tissues. The excimer laser of deep ultra-violet light is mainly used in Photoablation.The wavelength of laser used in photoablation is approximately 200 nm.

Uses
Photoablation is mainly used in corrective eye surgery procedures such as LASIK and LASEK. In fact, all laser eye surgeries are photoablation techniques in theory. It is mainly used to correct the shape of cornea or front part of the eye. Excimer laser is used to destroy (photoablate) part of the cornea, which automatically decreases refractive or optical power of the eye. The laser removes the tissues by vaporisation by transferring the energy to the target area. This procedure of photoablation with excimer lasers allows to correct many common eye problems. The procedure is relatively painless. Recovery from photoablation usually occurs within weeks.

Side effects
The main problem assossiated with photoablation is over or under correction of the patient's eye.Sometimes symptoms of halos or starbursts may occur.

Physics
When matter is exposed to excimer laser pulses,the pulse energy is absorbed in thin layers of matter.The high peak power of the deep uv light,when it is absorbed into the tiny volumes of the material,causes strong electronic bond breaking in the material.The resultant molecular fragments then expand in plasma plume   which carries the thermal energy away from the work place causing little or no damage  to the material surrounding the work place.