light

k..tell me wat is coherency????? see d definition ull realise urself

then how laser is coherent

explain karna hai toh kar ???????

dude .. c its like this ..
ordinary light consists of light emitted due to electronic excitations at the atmic level (say in an ordinary tube light) .. since these excitations are random, there is no coherence among the various wave trains emitted as visible light during de-excitation

y is laser coherent ?? well thats the working principle behid it .. stimulated emission to achieve coherence .. or near coherence atleast .. as the energy emitted during de-excitation is released simultaneously and in the same diraection bcoz of stimulated emission .. einstein was a gr8 man !

Dude.......sumeet...........dont be rude.....

I want you to realise the answer urself.....BY THINKING.........
if i just give out d answer it may not be of much use coz ther may be a tendency tht u may forget it and if u realise the answer yourself....THEN YOU WILL NEVER FORGET IT.

so giv sum respect to elders understand?

sorry !!!!!!