Homebrew PCBs

I do not think you want to use an aperture to get a round beam since it will
waste power.  As you suggested, cylindrical lenses will allow you to
selectively focus X & Y independently.

Mirrors curved in one plane will also work.

Bertho

 

From:  Slavko Kocjancic   Sent: Monday, November 18, 2013 03:37



On 11/18/2013 07:25 AM, Cristian wrote:
> 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
>
>
Actualy I don't know what aproach is better. Both seems to work, and 
both have specific problems.
I know that I can make laser beam round with aperture in widened beam. 
But maybe there is option to use some cylindrical lense too. If that 
works then there is no power loss. But finding the proper lense can be 
problematic.

And LED is little problematic too as light is not collimated. And I dont 
have any lenses on stock to try to make beam more paralel. In the led 
there is one chip of aprox 2x2mm and covered with transparent dome. I 
think to get most of them I need lense with short focal length to 
capture most of led. Maybe the gless ball is the right one (I don't have 
it to test).
Just need to find the source of lenses and make few tests...