Medical Applications of Laser

Introduction

According to the first report which was published about the radiation of laser in the year 1960 by Maiman showed many of the applications of laser in different fields. Among these applications the most advancement is in the surgery of medical lasers. There are different kinds of lasers which are used as tools in the field of medicine. At first, the application of laser was first limited to the field of ophthalmology and it is the most developed laser surgery of the time. Argon laser is used in the retinal detachment. There are many other applications of lasers for the purpose of therapy. For example, the tumors are diagnosed by the help of fluorescence dyes and caries are diagnosed by the spectroscopial analysis by the help of the plasma sparks [1]. The lasers were first used in the field of ophthalmology because eye is the first and the easy accessible organ due to increased transparency. In the year 1956 Meyer-Schwickerath identified the coagulative effects of the flash lamps of xenon on the retinal tissues. The lasers were invented in the year 1960 and in the year 1961 its experimental studies were published. Soon after that problem of retinal detachment was treated with the help of lasers and after a few years the use of laser in the field of dentistry was also discovered by Goldman et al (1964). In the initial years, ruby lasers were used in the treatment. The laser systems are classified as the as continuous wave and the lasers and pulsed lasers. The gas lasers and the solid laser are included among the continuous wave lasers and the dye lasers, solid-state lasers and excimer lasers are included in the pulsed lasers.

The first laser was the ruby laser which was pumped with the help of the xenon flash lamp. There are several spikes in the output of these lasers. The complete duration can be identified by the flash which is according to the lifetime of the upper state of the transition of the laser. In ruby laser it is about 1ms. There is some advancement in the lasers like Q switching which can give Concepts of Physics behind Laser [2].

Concepts of Physics behind Laser

Reflection and refraction When the electromagnetic radiations are returned from the surfaces to which they are incident is called as reflection [3]. A reflecting surface is the margin between the two materials that have different refractive index like a human tissue and air. The law of reflection needs the normal incident wave, reflecting surface and the reflected beams on one plane which is called as the plane of incidence.

Figure 1 Geometry of specular Reflection and Refraction

The above given figure explains the process of reflection and refraction and the angles ? and ?' of the figure can be calculated among the normal surface and the incident ray and between the normal and the reflected ray. The normal surface is considered as plain with small irregularities as compared to the wavelength of ...