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

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

515 nm Osram versus DPSS 532nm beam Quality ?

R

robertkoa

0
Joined
Sep 21, 2011
Messages
96
Points
8
People talk about DPSS having better beam quality than direct diode but I am comparing a 5mw DPSS with UV Filter to the Osram 515nm at 5mw .

Both supposedly have a 1.1 mm beam so not a square elliptical etc on the Osram ?

These are waterproof CR 123 Lasers with APC and glass lenses constant duty from Z-Bolt .

Which one has better beam ?
 





A 5mw laser, wow, that's a lot of power. :p
 
Last edited:
RedCowboy said:
A 5mw laser, wow, all in one beam is it......boggles the mind, too spooky for me, I will stick to my 1kw lasers.
Click to expand...

What?

Anyway, DPSS lasers almost always have better beam quality than diode lasers, simply due to the way they operate.

Though I've never tested an Osram 515nm diode specifically, so I can't say for sure.
 
:D
RedCowboy said:
A 5mw laser, wow, all in one beam is it......boggles the mind, too spooky for me, I will stick to my 1kw lasers.
Click to expand...

Not everyone can handle a true 5 mw - has a very narrow beam...
More than just courage and bravado...you need skills.

Especially the Osram 515nm - can kill a mosquito in less than 8 minutes....
 
Last edited:
Yes DPSS quality is hard to beat, the single mode greens are getting better, but artifacts and splash are noticeable, a 532 DPSS is super clean when they are not mode hoping are being temperature sensitive.
 
Last edited:
ultimatekaiser said:
depends what you are interpreting as beam quality...:whistle:
Click to expand...

My 589nm hits clouds i can see the dot on the cloud.

i had to put binoculars through my green lasers to do that.

still can't decide what i like more 589 or 612.


they both look natural. 589 is so relaxing in a dark room.

A well built dpss is amazing i wonder if my jetlaser 473 will hit a cloud too.
 
RedCowboy said:
Yes DPSS quality is hard to beat, the single mode greens are getting better, but artifacts and splash are noticeable, a 532 DPSS is super clean when they are not mode hoping are being temperature sensitive.
Click to expand...

Red- when you guys say mode hopping is that when the frequency shifts or the frequency doubling goes out of alignment etc. ?
Does the Beam flicker or shift kind of ?
 
TEM00 is a dot, that's what we want, but sometimes they hop usually to a double dot and back, through the grin and focus lens you often don't notice. TEM10 and TEM20 are the ones I have seen sometimes with the collimating lens removed, but I still love 532nm, I use a wider longer focal length collimating lens in a slider to zoom to a tiny spot my 532 output, they are capable of very tight spots at distance.

tem_modes.png


450px-Green_laser_pointer_internal.gif


The pump diode in a Diode Pumped Solid State ( DPSS ) 532nm laser is a 808nm that pumps a 2 part bonded crystal of ndyv04 and ktp, the yvo4 turns 808 into 1064nm and the kyp doubles the frequency from 1064nm to 532nm.

The number 532nm is the distance between waves ( 532 billionths of a meter ) so 532 is higher in frequency than 1064 as the waves are twice as close together.

There is a gradient index lens and ir filter and then a double concave double convex act as an expander to give a good looking beam over distance, it's actually needle thin coming out of the crystal but diverges more rapidly. So the expander fixes that.

During the crystal doubling mode hoping can occur, temperature and alignment can be a factor.

Now a 515nm or 520nm direct is like the 808nm pump, it's a semiconductor laser diode, a p/n junction emitting photons via of a substrate and is much more dependable, but the beam is not as clean or round.

However single mode direct greens are getting better all the time, I have been looking at the nichia 4216 HERE

The pics below is DTR's I think, and they overlap a bit, but the ancient 532 is round and clean.

iYkn0x.jpg
 
Last edited:
Honestly, diodes can get to be quite good with lots of work, but DPSS generally always results in a superior beam in many ways. But diodes can rival them if tons of money is sunk into them. But if we're just talking divergence and profile, it's more of a game of optics placement. Little else matters unless you're getting into noise and longitudinal modes and such.
 
Last edited:
Sure, but the average buyer spends a 150 dollars on a 100mw 515nm hand held laser and 15 dollars on a 100mw 532nm dpss laser and the trade off other than 10x the price is reliability for beam quality, but the directs are getting better, I like that 4216 and plan to get one soon, but I have many pedigreed 532's that are quite excellent, but I junked 5x as many to get them, so the cost is more like 2 to 1 not 10 to 1 when you factor in picking out the keepers.
 
Last edited:
Reliability in the cold perhaps somewhat. :) the bare GaN based diodes definitely handle cold fairly well as they generate lots of heat. But lifetime wise, I'd wager they're similar. Making a 520 circular and fine, takes a fair bit of skill, but worth it.
 
Thanks Red good explanation.

I think the Osram 515nm is one of the better Diodes ..they brag about the beam quality and I think it's supposed to be round and only 1.1 millimeter.

For my Lasers I like the idea of safer 5 mw but visible beam ...the Zbolts have this in 532nm and 515nm Osram...their Blue is apparently visible at less brightness 450nm and has an a elliptical beam sloppier shape.

Another benefit of 5mw ( constant duty) is possibly using outside there will be limited off axis visibility especially with blue.

I would like a 462 Blue in 5mw if I could get one .

For some reason the Z Bolt Lasers have very visible beams in green and even the Blue 450nm is visible - according to Astronomy Pointer users. The glass lenses and APC circuits probably help...

Although - IF the beam is elliptical or square and 3 millimeter instead of 1.1 millimeter- the Candela is far less and visible beam at 5mw goes bye bye...right ?

Max at Lazerer will do a 515nm 5 milliwatt at great price but thinks I won't see a beam ...odd.

Bad optics ?
 
Last edited:
Rayleigh scattering can be affected by humidity and angle of observation as well as other factors.

Have you tested both side by side, if so then one may be over spec or one under spec.
 
You must log in or register to reply here.


Back
Top