Laser is (light amplification by stimulated emission of radiation) is a device which produce light beam of following characterstics.
- highly coherance
- highly intense
- unidirectional propagation
Helium-Neon laser device is the best Apartments for commercial production of laser beam. The device consists of cylindrical glass tube having length 15mm breath 5 mm. The two plane mirror M1 and M2 are placed parallel beside the tube.
The mirror M1 is perfectly effecting and M2 is partially effecting. The tube is connected to DC supply through the electron. The tube is completely filled with the mixture of Helium-Neon gases in the ratio of 5:1 at atmospheric pressure 1 torr (33.33 mm of HG). The production of laser beam now can be explained below.
At first high electric potential is connected to the tube. The glass inside the tube is ionized and transaction of He and Ne takes place. At first He electron are excited from 1s level to 2s level ,where energy level is 20.61 electron volt .In this case electron of the He remain in this state for long time.
similarly, Neon electrons are also excited from the 2s level to 5s level where your eneryg level is 1.6 electron volt. Now,neon electron is into interacted by helium electron and transistion occurs from 5s level to 3s level,where energy level is 18.70 electron volt. This emission is laser emission and laser beam of wavelength 632.8nm is emitted.
After, this spontaneous emission is occurs 3s level to 3p level and finally reach the ground state with the emission of non radioactive emmission.The neon electron in the energy level 3s goes back and forth and finally a beam of highly monochromatic coherancy and intense beam is produced which is we called laser beam.
Application of laser beam
- Laser beam has wide application bloodless surgery and treatment of soft.
- It is used in industrial field such as cutting of metal ,drilling of metal and welding of metal.
- It is used in holography.
- Laser beam is used in survey of field to locate the exact position of object and measurement of distance between two object and measurement of depth of sea.
- It is used in transformation of communication signal.
Question of day
1)Define current density?
2)what is x-ray?
3)what do you mean by titration?