pencil lead thin 445nm beam-no prisms no cylinderical lens

[kecked]

all that sounds fine but on my wall it sure looks good. proof is in what works for your situation. simpler optics would be nice to get the same result. what would you suggest would be an equivalent to what I did with less optics?

I have fog tonight and tried out a beamshow. Works well for that as well.

I have prisms and lenses coming so when they come I'll try those as well. In the mean time this method works well for my needs.

Sometimes the science just gets in the way of the art.......In this case I don't care why it works just that it does.

[CrazyMonkey]

I just got a LPM and discovered my power was way under spec.
Then I realized I had a red Axixz lens.(they look blue).
They eat easily half of 445. I would say back reflection may be an issue,
but these 445 diodes seem nearly indestructible, lol..
Keep in mind though, it may be up to half a watt the lens may dissipate as heat!

[kecked]

I'LL DEFINITELY TRY THE ONES COATED FOR 445NM WHEN THEY GET THEM! i WAS NOT AWARE OF THE LOSE BEING THAT HIGH. IT LOOKS LIKE A SIMPLE AR COATING ON THE RED LENS TO MY EYE. NEVER BOTHER TO MEASURE LOSE SINCE i HAVE SOO MUCH EXCESS BLUE.(30 DAYS AGO i WAS PROUD THAT i HAD 50MW OF 445NM)

[CrazyMonkey]

Yeah, I had no idea either. Kind of a kick to the face, lol.
Can't wait to get my 405-445 lenses. I have a blue lens,
but it's dot is horrible.

And the Red ones usually have a blue reflection.
The blue ones usually have a yellow reflection.
(the ones I've used)

[mccarrot]

all that sounds fine but on my wall it sure looks good. proof is in what works for your situation. simpler optics would be nice to get the same result. what would you suggest would be an equivalent to what I did with less optics?

I have fog tonight and tried out a beamshow. Works well for that as well.

I have prisms and lenses coming so when they come I'll try those as well. In the mean time this method works well for my needs.

Sometimes the science just gets in the way of the art.......In this case I don't care why it works just that it does.

Sure you get a nice beam at 20 feet with >3mRad, it simply did not got the time to diverge. now go and measuere the beam at 200 feet and post the results here, then you know what i mean

But sure for small areas and beamshows only >3mRad beams will be ok, but mixing it with a 1mRad 660nm beam will give you problems at longer distances.

[mccarrot]

It physics,
if you make the beam smaller the divergence gets bigger
If you make the beam bigger the divergence get smaller

the fast axis the 445nm diode is a very small beam with a very high divergence. we use prismpairs or cylidrical lensen (like you discribed) to make the beam bigger and the divergence lower.

[FourDee]

The two axis of the beam are different.
What you want is something that will only change one axis (like a prism or a cyl lens)

[mccarrot]

for example the 445nm diode with a FL4,6 lens gives a beam like this:

-

where the fast axis is 0,7mm with 2,6-3mrad
and the slow axis 3mm with 0,2 mrad.

For lasershow use you want to have both axis as equal as possible.


PS does the topicstarte allready tested his "mirracle pencil beam" solution at 200feet?

It would be great to see him break the laws of phisics

[allthatwhichis]

for example the 445nm diode with a FL4,6 lens gives a beam like this:

-

where the fast axis is 0,7mm with 2,6-3mrad
and the slow axis 3mm with 0,2 mrad.

Can't you then go back and use a prism or cyl lense to correct the fast axis?

[mccarrot]

Can't you then go back and use a prism or cyl lense to correct the fast axis?

yes...... I was just trying to explain to king4quater.......



There is NO need to use telescopes with only one or 2 diodes. if you need a pencil thin beam just take a aspheric lens with a very small FL but expect a very high divergence.

If you want very low divergence take a lens with a high FL but then you will have a fat beam..... get it?

This is the last post I will make in this topic, someone else can take over, getting a little bit tired... too many LPF'ers arround lately....