Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Mitsubishi 635nm diode divergence at 350 feet

Joined
Sep 22, 2010
Messages
1,358
Points
48
Nice job with the comparison.

To be fair they are worse than the 445s, I wouldn't want to inadvertently foster that idea, but for a handheld laser that you're going to shine into the sky or across a room i don't think it's necessary to get into corrective optics. I'm never one to say that there's something wrong with the pursuit of perfection, in fact those who want to experiment with optics to obtain the very best beam possible are to be commended IMO, but I don't feel bad about having a little handheld that has a bit of a wider flatter beam than normal.. still looks like a laser to me and everyone I show it to..

++ to this. To the average person a fat beam is more impressive anyways.
 





Fiddy

0
Joined
May 22, 2011
Messages
2,726
Points
63
The same kind of silly-good divergence can be had from the single-mode 635nm optnext diodes too.. but they do cost a good bit more. Probably worth it actually, but I wonder if they're as robust as these multimodes are.

Oath!

i put my 770mW 635nm Mitsubishi next to my 210mW optnext 635nm and the difference is just ridiculous!

tho the optnext is more than twice the price of the mitsubishi....
 

DJNY

0
Joined
Nov 2, 2009
Messages
5,991
Points
83
Great comparison! (+1)

I´m looking forward to the day I can get one in a medium-sized handheld with a "good" divergence, at least like with the 445nm, and with >700mW power :)
 
Joined
Nov 7, 2008
Messages
5,725
Points
0
I don't know if that'll ever happen. I'm not an expert in the manufacture of laser diodes, but I think that the wavelength of the light produced has some influence on the beam properties of these new types of multimode diodes. The blue diodes have lower natural divergence than the reds, seemingly proportional to the difference in wavelength, even though the structure of each is very similar. Therefore I don't think that reds will ever have the same natural beam properties as blue diodes with the same structure. The future will no doubt hold new types of structures that will outperform what we see today though.
 
Last edited:
Joined
Feb 1, 2008
Messages
2,894
Points
0
^^That's correct. The lasing wavelength that is emitted from the die greatly affects the fast axis to slow axis divergence ratio. You'll see that the future multi-mode 525nm diode will have divergence comparable to the 445s.
 
Joined
Nov 7, 2008
Messages
5,725
Points
0
Ok, so this is weird as it came to me in a dream (lol) so it's probably not going to work.

What about a convex lens, but with a lip around the edge?


Can you draw something up? The only potential problem I can think of without being sure I'm understanding what you mean is that the lens you describe sounds difficult to make.
 
Joined
May 22, 2007
Messages
351
Points
0
Good dot comparison. The good old red laser has the best divergence.

And that's why I still enjoy my good old-fashioned 660nm red pocket mini.

Ash - Great video. I wish I had some nice safe unbroken space to run my lasers long distance. You helped make up my mind to what type of 635nm diode I'd like to use in my next build.
 

mfo

0
Joined
Jul 3, 2009
Messages
3,394
Points
0
Can you draw something up? The only potential problem I can think of without being sure I'm understanding what you mean is that the lens you describe sounds difficult to make.

Hmm. This might sound a tad perverted, but I think it'll get the point across.

You know how when you take a condom out of the wrapper, how the edges are thick since it's rolled up? What if the edge of the lens sort of had that thickness to it?

Oh yeah, and I suck at drawing. If need be though, I'm sure I could come up with something.
 
Last edited:
Joined
Mar 27, 2011
Messages
14,125
Points
113
Hmm. This might sound a tad perverted, but I think it'll get the point across.

You know how when you take a condom out of the wrapper, how the edges are thick since it's rolled up? What if the edge of the lens sort of had that thickness to it?

Oh yeah, and I suck at drawing. If need be though, I'm sure I could come up with something.

And so the condom lens is born!:crackup:
 
Joined
Nov 16, 2011
Messages
8
Points
0
Here is a video I just shot of my 365mW mitsubishi 635nm from a distance of 350 feet.
The "dot" is more than 24 inches across at this distance. :p

The other lasers are a 1.1W 445nm, a 180mW 660nm, and a 65mW "cute" green. :D
Hi, can I ask how big is the other red "dot"? Looks like about 1" diameter? Is there anything available "off the shelf" that can achieve this?
 
Joined
Mar 27, 2011
Messages
14,125
Points
113
Lmfao!

If someone makes this, I want credits.

But seriously, I don't know why this lens came to me in a dream. I think I need to stay away from lasers for a while =\

Actually I'm 90% certain I've seen a lens like that somewhere. Much thicker toward the edges, thinner in the middle.... but can't for the life of me remember where. Possibly it's a childhood memory... my grandfather had loads of magnifying lenses lying around all the time.

You get the credit for the idea... but I coined the term:na:

That is really bad. :(

Actually it's better than what I expected. Yes it's worse than 445's, but it's still perfectly serviceable as a pointer.

To date I've never had anyone say "hey that's a weird dot".... I think we're just a bit anal about these kinds of things.

Recommended for use with the Dilda Lazor. :na:

Yup, that was cheap.

Yup, always use proper protection:shhh:

Erm... dust cap:p
 




Top