What is the basic principle of excimer laser?
Laser action in an excimer molecule occurs because it has a bound (associative) excited state, but a repulsive (dissociative) ground state. Noble gases such as xenon and krypton are highly inert and do not usually form chemical compounds.
On what principle does laser work?
stimulated emission
The principle of laser amplification is stimulated emission.
What is the excimer laser used for?
They are most commonly used to correct myopia (nearsightedness) but can also be used to correct hyperopia (farsightedness) and astigmatism. The excimer laser alters the refractive state of the eye by removing tissue from the anterior cornea through a process known as photoablative decomposition.
How is excimer laser produced?
In an excimer laser, a pulsed gas discharge produces excited molecules with a nonbinding electronic ground state. This means that these molecules disassociate after spontaneous or stimulated emission, so that reabsorption of the radiation is not possible.
What wavelength is excimer laser?
193 nm
The term excimer results from a contraction of the words ‘excited state dimer,’ which indicates the excited-state nature of the lasing molecule. The lasers operate primarily in the ultraviolet spectral region with wavelengths at 193 nm (ArF), 248 nm (KrF), 308 nm (XeCl), and 351 nm (XeF).
Why excimer laser is called so?
The name excimer is derived from excited dimers. The emission from each excimer laser varies for the different gases (see Table 2.3). The emission of all the excimer lasers is in the UV at wavelengths shorter than 350 nm.
Is excimer a laser radiation?
Excimer lasers, along with nitrogen lasers, are the most popular gas lasers generating radiation in the ultraviolet range. The active medium is a mixture of a noble gas, halogen gas, and a buffer gas—usually neon.
What is mean by excimer laser?
Excimer is a term used today to describe a family of lasers with similar output characteristics, in that they all emit powerful pulses lasting nanoseconds or tens of nanoseconds, at wavelengths in or near the ultraviolet, and the lasing medium is a diatomic molecule, or dimer, in which the component atoms are bound in …
