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

Thinking of Buying the 500mW Laserglow 445 Polaris...Please advise

Joined
Jun 28, 2010
Messages
155
Points
0
If the Polaris really had 0.9 mrad divergence with a 3-4 mm beam at its aperture, the dot would be ~37 mm at 120 feet.

The dot in the last picture is DEFINITELY larger than 37 mm.
 
Last edited:





Joined
Nov 17, 2009
Messages
2,031
Points
83
Actually, in picture 2, at 40 feet the dot appears to be ~30mm, going by the cm scale on the picture on the left of the ruler.

In picture 3, at 120 feet, the dot on the fast axis appears to be ~55mm. (Which, yes, is a revision from 3 inches, but, look at it yourself; draw some lines in an editing program...)

That would give ~ 1.0 mrad, not anywhere near 2.0?

Really, doing divergence calculations off of a picture like this really isn't the best way to go.

It's hard to determine what is actually the dot size and what is camera sensor bloom or optical artifacts, and the perspective of the images makes it hard to get a very good measurement.
 
Joined
Jun 28, 2010
Messages
155
Points
0
Yeah, the fast axis appears to be ~55 mm in picture 3.

The beam diameter is 3-4 mm at the aperture according to laserglow's site, so divergence is ~1.4 mrad according to the last pic.
 
Last edited:
Joined
Sep 2, 2010
Messages
24
Points
0
aryntha, do you know, what is the power of this Polaris? Does the most powerful Polaris have just the same circle beam and so good divergence? And what Polaris did you buy (what power)?
 

Justin

0
Joined
Feb 16, 2007
Messages
496
Points
0
Just so you know, these pictures were not produced to show divergence, just the ellipticity of the beam. I used my iPhone which, while it is a kick-ass phone, has a very hard time focusing on 447 nm laser beams. The apparent size of the dot in these pictures is not at all what it looked like in real life, and actually my laser tech and I were very impressed with the actual divergence of the laser over long range when measured properly. The average size of the laser spot ((fast axis+slow axis)/2) gives just under 1 mrad divergence when you measure with the naked eye.

Also, in addition to the fact that these pictures were taken hastily and with poor equipment, when measuring divergence you generally only count the portion of the beam which represents 80% of the total output power of the laser, so you don't just count the widest visible point. Due to the iPhone's poor focus and nonlinear gain ratio at this wavelength, trying to deduce the divergence from these pictures is futile and will lead to very inaccurate results. We stand by the divergence figures prepared by our technical staff and, as always, we guarantee all specifications to be accurate.

Please take these pictures as evidence that the laser has corrective optics which reduce the ellipticity of the beam (this was the original intent), but don't try to judge the actual divergence using these data as you will be incorrect.
 
Joined
Sep 10, 2010
Messages
207
Points
28
looking forward to the review :)

What I like in laserglow is that they get an already very good CNI laser and tune it for an excelent product. If the aryntha review proves that the divergence is low and the dot is near round, this will be my next laser for sure. A 445nm with a good beam profile is super sexy. :)

Cheers!
 
Joined
Nov 17, 2009
Messages
2,031
Points
83
Hey everyone - my review is here. (link).

Understand that this is "only" a Polaris-100, as it's what I could afford at the time (Also, these diodes perform 'cleaner' at lower powers, with less transverse modes, so, already having plenty of 'eyeball burner' 445s, I wanted to concentrate on beam quality.)

But overall, I think people will still be pleased with its performance. I know there will be people who will scoff at the power, but as I've said before - power isn't everything.

Note that this sort of beam profile, as Justin states, is available in the 50-400mW models.

Regina, since I know you're after beam visibility -- I think it'd be great for you to aim for a Polaris-400 and get the same kind of optics in really not half-bad power.

I hope this helps.
 
Joined
Jun 28, 2010
Messages
155
Points
0
Justin, since the 1W Polaris doesn't contain any corrective optics, what is its divergence?
 




Top