Angelina and then the hair stays away for a year and doesn't grow back in that time?
It seems to be so and it is consistent with the information I have got.
From what I have found, the laser destroys the hair root and the hair falls out. Since the root is no longer there, no new hair can grow back.
The problem is the colour of the root and how the laser light is absorbed. With colourless roots, too little energy is absorbed and the root is not properly destroyed. That is why grey or white hairs are excluded, as far as I know. Also, some people have colourless roots with very dark hair.