Help with focusing blue laser/wierd beam shape?

[AthruZ]

I have just finished my first blue laser build using PHR-803T, with AxiZ housing. But when I attempt to focus, one I can't seem to focus the beam, 2 at one extreme (lens closest to diode unmodified) i get a weird elliptical shaped beam and still unfocused and fairly large from like 2 feet away. I have no idea whats goin on, can some one help me out-Please. THANKS

 

[rog8811]

Re: Help with focusing blue laser/wierd beam shape

The focus point is over just a couple of degrees movement of the lens, it is very easy to go past it without noticing....
There is one other posibility I can think of, if you have a chrome focus bezel on the front of the plastic lens unit, try taking it off and wind in the lens without it.

Regards rog8811

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

I have just finished my first blue laser build using PHR-803T, with AxiZ housing.  But when I attempt to focus, one I can't seem to focus the beam, 2 at one extreme (lens closest to diode unmodified) i get a weird elliptical shaped beam and still unfocused and fairly large from like 2 feet away.  I have no idea whats goin on, can some one help me out-Please.  THANKS

Your diode is NOT pressed all the way into the module.  Do you have a silver, metal focus ring on the black, plastic lens nut?  If so, you can remove it and screw the lens in deeper.  That might get you close enough to the diode.  If not, then you will have to go back inside the module and get the diode pressed farther into the module head.  It should actually be '"recessed"" into the module head.  It should NOT be "flush" with the back surface of the module head.

Yes, I know that is a Merideth adapter, but the concept is the same.

Peace,
dave

 

[ElektroFreak]

Re: Help with focusing blue laser/wierd beam shape

Most laser diodes emit an elliptical shaped beam, so that much is normal. Rog8811 is correct: As far as focusing, if you have the little chrome focusing ring attached, try removing it and then focus using black lens assembly itself. I've seen those focusing rings interfere with focusing ability before.

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

;D ;D ;D ;D ;D ;D overkill  ;D ;D ;D ;D ;D

It must be a holiday  

Peace,
dave

 

[AthruZ]

Re: Help with focusing blue laser/wierd beam shape

the plastic, threaded part holding/containing the lens is black and the case that holds the diode is silver/chrome.

and if the diode does need to be pressed in more and suggestions on how to get it in further without damaging the pins?

 

[AthruZ]

Re: Help with focusing blue laser/wierd beam shape

one more thing i forgot the ring has been removed (the outer chrome ring) but still using the spring.

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

[quote author=AthruZ link=1230749328/0#5 date=1230750138]


[highlight]**EDITED RESPONSE**[/highlight]

 Did the lens nut (the black plastic part) "bottom out" in the module?  Do you have the back of the lens nut "opened up"?  Is it the stock spring under the lens nut?

Peace,
dave

 

[rog8811]

Re: Help with focusing blue laser/wierd beam shape

The picture below shows the Aixiz module with the chrome bezel, I assume from what you say that yours does not.... you could try removing the spring, it may be getting coilbound and stopping full movement of the lens. While you have the lens out have a good look at the window on the LD to make sure there are no specks of dirt on it.

If your driver is soldered to the LD you are going to find it hard to press it into the housing any further.

Regards rog8811

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

The picture below shows the Aixiz module with the chrome bezel, I assume from what you say that yours does not....

If your driver is soldered to the LD you are going to find it hard to press it into the housing any further.

Regards rog8811

Nice picture, Rog <saved>

Peace,
dave

 

[AthruZ]

Re: Help with focusing blue laser/wierd beam shape

thanks for the diagram and thanks to all who have answered my call. well i think i found the focus point, more or less, but now hows the best way to get a distant focal point. maybe that should be obvious but i am finding it difficult to get a good distant focus, and of coarse there needs to be a constant changes as the distance changes. any tips on this. thanks again.

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

thanks for the diagram and thanks to all who have answered my call.  well i think i found the focus point, more or less, but now hows the best way to get a distant focal point.  maybe that should be obvious but i am finding it difficult to get a good distant focus, and of coarse there needs to be a constant changes as the distance changes.  any tips on this.  thanks again.

To get it to focus farther away, you have to actually screw the lens in farther.  Is it in as deep as it will go? Is there not enough of it left "sticking out" that you cannot get hold of it to turn it?

Peace,
dave

 

[rog8811]

Re: Help with focusing blue laser/wierd beam shape

Do you wear glasses?  If so look over the top of them

Regards rog8811

 

[daguin]

Re: Help with focusing blue laser/wierd beam shape

Do you wear glasses?  If so look over the top of them

Regards rog8811

The eye has trouble "seeing" the 405nm light.  Have someone else stand by the place that you are trying to focus it to if it is far away.  It may just "LOOK" like it isn't focused to you.  They can tell you when it is a very small dot.  Then you look and compare it to what you are "seeing."  It is probably very different.


[highlight]**EDIT** [/highlight] WARNING -- They look at the wall NOT toward the laser!!!!


Peace,
dave

 

[AthruZ]

Re: Help with focusing blue laser/wierd beam shape

i have glasses for 532nm but not for 4xx nm (whatever the exact wavelength is) but now i think you weren't referring to protective glasses.  
well i think i have everything mostly figure out, feel free to add any thoughts.
i have a good start at a good focal point probably do need to get glasses to help.  thanks again to all who helped.

 

[rog8811]

Re: Help with focusing blue laser/wierd beam shape

but now i think you weren't referring to protective glasses.

Correct, I cannot focus on the dot through my prescription glasses but I can without them strangely enough.

Regards rog8811