low level lasers

Ruby Laser - In 1960, T .H. Maiman constructed the first laser using a Ruby crystal. Ruby is a crystalline form of silica(Al 2 O 3 ) with a slight natural doping of chromium. It has the following advantages for being used as a laser. (i) It is a solid having suitably a..

It is material in which the laser action is made to take place. It may be solid, liquid or gas. Many lasers are named after the material used e.g. ruby laser, He-Ne laser, CO 2 laser, Nd: YAG laser etc. The most important characteristic ..

The development of the laser has opened many avenues of investigation and improved many others. The important characteristics that have contributed to its usefulness in these many areas are tile coherence, monochromaticity and great intensity of its radiation. (i) The smallest lasers..

The figure shows the elements of a type of laser that is often found in student laboratories. The glass discharge tube is filled with a 80%-20% mixture of the inert gases helium and neon. Helium is the "pumping" medium and neon is the "lasing" medium. The above figure is a simplified vers..

The below figure shows schematically how a population inversion can be achieved so that laser action-or lasing us it is called can occur. Atoms from the ground state E 1 are "pumped" up to an excited state E 3 , for example by the absorption of light energy from an intense continuous spec..

The space between soil particles on the surface of earth is called pore space. It is of two types - micro and macro pores. Most of the water is held in micro pores. Pores, which are available for plant roots. Surface soil pore spaces are generally filled with air and water. Water that per..

>Body fat - There is redistribution of fat to deeper parts of the body from the skin. In women, fat is generally stored in the hips and thighs, while in men it is stored in the abdominal area. Retention of water - The capacity of body cells to retain water decreases. This makes the skin dry and wri..

This laser consists of a discharge tube in the cylindrical shape containing helium Neon gas in the ratio 9:1 at a low pressure. Two mirrors M 1 and M 2 are placed at the ends to facilitate the longer availability of emitted photons. A large potential difference is applied bet..

The disease caused due to the deficiency is pernicious anemia. Symptoms of this disease are low haemoglobin levels, decreased number of erythrocytes and neurological manifestations. The deficiency of B 1 2 also causes numbness and tingling of fingers and toes. If the deficien..