This video explains characteristics of laser radiation. In our earlier session we have learnt about lasers, and also we learnt that properties of laser light are different from properties of light of ordinary sources.
Now in present session let us discuss about the characteristic properties of laser light.
Laser light is differentiated from ordinary light by four characteristics.
1. Coherence
2. Directionality
3. Monochromacity
4. High intensity
Now let us learn about them in detail.
COHERENCE:
We all know that, how visible light is emitted from the source. In an atom when the electrons are in excited state, it jumps from one state to another state or higher state to ground state which is said to be as transition. In ordinary light sources, the electronic transition takes place randomly. But when the light waves received from ordinary light source, their wavelength has no definite phase in space and time. Hence these light waves are said to be as incoherent. In the case of laser light, the electronic transition takes place in an orderly way and their wavelength has consistent phase with time, which is called as ‘Temporal Coherence’. Thus lack of coherence is said to be as incoherent and makes a noise said to be as ‘optical noise’. Laser light with coherence makes sound said to be as ‘optical music’. Due to the characteristic of coherence, laser light produces large amount of power of the order of 10 power 13 watts and can be focused in narrow space of linear dimension of 10 power -6 meters.

ที่มา : http://www.7active.in

ลิงค์ : http://youtu.be/BKVMw4jpDZw

อัพโหลดโดย : 7activestudio