At 07:59 PM 17-11-13, you wrote:
>After that I put 50mW/405nm laser on stand to get same height all
>the time and focused to have spot under 0.1mm. The shape of laser is
>not round as if I move in one direction the width is 0.06 and
>perpendicticular is 0.98mm.
To get the beam round you have to expand it with a lens, to pass the
expanded beam through a round aperture and to re-focus it.
Of course, you will lose a lot of power: 0.98 divided by 0.06 = 16.3
times is the amount of power you'll lose.
BTW: you have to choose a laser with better x/y ratio or to try
rounding a LED beam.
Cristian