Introduction to Excimer Laser

The excimer laser is a type of ultraviolet laser that produces high-energy pulses of light. It was developed in the 1970s and is used in a wide range of applications, including medicine, microelectronics, and materials processing. The word “excimer” is derived from the words “excited dimer,” referring to the excited state of the molecules that emit the laser light.

How Excimer Laser Works

The excimer laser works by exciting a gas mixture of halogens, such as chlorine or fluorine, and an inert gas, such as argon, with an electrical discharge. This produces a short-lived, excited dimer molecule, which rapidly decays to emit a high-energy photon of ultraviolet light. The wavelength of the emitted light is determined by the specific gas mixture used in the laser, and can range from 157 to 351 nanometers.

Applications of Excimer Laser

The excimer laser has numerous applications, including in materials processing, microelectronics, and medicine. In materials processing, it is used to etch and pattern silicon wafers, as well as to remove thin layers of material in a process called ablation. In microelectronics, it is used to create high-resolution patterns on computer chips and other electronic components.

Example of Excimer Laser in Medicine

One of the most important applications of the excimer laser is in medicine, where it is used to correct refractive errors in the eye, such as nearsightedness, farsightedness, and astigmatism. In a procedure called LASIK (laser-assisted in situ keratomileusis), the excimer laser is used to reshape the cornea of the eye, allowing light to focus properly on the retina. LASIK has become a popular alternative to glasses and contact lenses, with millions of procedures performed worldwide each year.