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FrozenGate by Avery

Laserglow Polaris-100 447nm with Corrective Optics - Quick Review

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Nov 17, 2009
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So begins my quick review of my Laserglow Polaris-100 447nm laser.


Overview:

Some may ask, "Why would someone spend upwards of $300 for a 445/447nm blue laser when 1w builds are available for around $200?" My first answer would be, that power isn't everything (nor is burning capability) - a lot of laser enthusiasts are into lasers for a lot more reasons than that. Sure, I love me my burning lasers, but I also like my odd wavelengths and gas lasers just as much.

When Laserglow released their Polaris series recently, essentially Laserglow's own version of a custom CNI PGL-III-C 447nm blue, a lot of people asked, "Why would anyone want that?"

Well, let me enumerate.

  • Laserglow's customer service.

    While there are bumps in the road when it comes to any company, if you research the forum you'll see that Laserglow's customer service is generally viewed as favorable around here. If you have a problem - email them, call them up, whatever: they will respond. That's hard to be said for CNI themselves, who are essentially an industrial distributor. It's impossible to be said for Wicked lately; and the only experiences I'd say that would compare would be builds by forum members such as Yobresal and some others.

    I've had a few lasers die within warranty. Shipping and interaction was downright frightening overseas. If you're in the US, Laserglow is in Canada, and they know what they're doing. I've done exchanges with Laserglow with no problems in the past, and Justin (who is active on this forum) has helped me with my Aries even though it was out of warranty. (No guarantee on this - but the point is, the company is attentive and available.)

  • Beam quality.

    Laserglow has claimed that the Polaris is not the same as a DIY build, and does include corrective optics. While we've found some really efficient optics here (405-G-1, etc) the result of most 445nm blue lasers at a distance is essentially the beam profile of a line, not a dot (gaussian). As I'll show here, this claim seems to be correct.

  • Time in transit and customs games.

    Laserglow's lasers are FDA compliant "for real". If you order one, it'll show up. No watching the tracking screen in a panic. Enough said.

The desire for a lower power 445nm blue is twofold actually: the 445nm diodes actually behave better and are closer to singlemode/TEM00 the closer you get to 50-100mW. Going above 100mW, more modes seem to develop, and while more power is available, this occurs in the form of additional transverse modes in the beam profile. So, combining a lower power with corrective optics, in theory, should get me a pretty nice looking 445nm laser. (Remember that just a year ago, 150mW of blue for $389 would be considered unthinkable. We tend to get spoiled fast here.)

This review should help those looking at the Polaris in any power rating however. For those considering the 50-400mW versions, the beam profile shots should be very informative. For those looking at the 500-1000mW models, at least you can get an idea of what's provided, the fit and finish, and the sort of experience (as far as on spec ratings) to expect.

Note, the maximum power that these lasers are provided in with corrective optics is 400mW. Going above this is too much power for the lens set, in addition to some losses in the optics. Laserglow has assured me that beam specs on this laser (the Polaris-100) are what you can expect from models from the Polaris-50 to Polaris-200. (Polaris-200 ranging from 200mW-499mW; quite the range.) Powers above 400mW do not include corrective optics. It's unclear if some Polaris-200 models which measure in at >400mW would not include the corrective optics; but it seems that this would be the case - with Justin from Laserglow saying any "Polaris series laser under 400mW will be similar to this."

I won't be concentrating on beamshots (though I will provide some idea of visibility) - this is why I'm calling it a 'quick' review; we get some power ratings and most importantly -- beam profile shots, to see if the corrective optics really do what they should.


Claimed Specs and Vitals:

Model: Laserglow Polaris-100
Host Style: PGL-III-C with keylock, side switch, and safety plug.
Frequency: 447nm.
Power: 100mW minimum, 180mW max.
Mode: Multimode.
Modulation: CW
Beam diameter at aperture: ~3-4mm.
Rated divergence: 0.9mRad (very good)
Power source: 2x CR123A 3.0v (Don't use 3.6v)
Price: $389 - but watch for Laserglow's sales.
Warranty: 6 months
Duty cycle: ... Really as long as you want.


THE LASER:

Most folks here have seen the Laserglow "Aries-style" (PGL-III-C) host, so this won't be an unfamiliar sight to you.

As Supplied, with case:
1-case.jpg

As with Laserglow's Aries-style models, they provide a custom fitting metal carrying case. The case includes pull-out foam areas to store your batteries, as well as the keys and interlock plug for the laser.

SIDE VIEW:
2-sideview.jpg

Not too much new to see here; Aries/PGL-III-C style host with the usual nice laser (of course!) engraved logo of the Polaris model.

POWER SOURCE:
3-cells.jpg

Unlike most of Laserglow's previous models in this host and unlike most other CNI PGL-III-C models, this laser does not use 2xAlkaline C batteries, or 1x18650 LiIon batteries. It uses 2x3.0v (important! Don't use 3.6v!) primary or rechargeable CR123A batteries. I'm using LiFePo 3.0v 900mAh batteries in this laser; and they actually seem to hold up rather well.

POWER SOURCE:
4-frontend.jpg

Currently missing from the Polaris is the rotary beam shutter seen on most other DPSS-based Aries-style or PGL-III-C lasers. This being the second diode laser that has been fitted into an Aries-style host (the first being the red diode 'Orion'), the optics and initial width of the diode beam require a larger aperture, and this cannot at this time accommodate the rotary shutter mechanics.

Note that I'm glad to see the 'aluminum slider' shutter of the old Orion going away. That thing was horrible. (Justin, if you're reading this.. Is there any way I can get one of these heads on my Orion-HV? :) ) - The fit and finish on this is tight, feels solid, and includes no funny business. While I'd like to see them develop a diode-sized rotary shutter, this will certainly do for now.

MEASUREMENTS:

On to the measurements. Laserglow claims the Polaris-100 product line will do 100-190mW sustained with a peak of 190mW.

Included on the laser is a sticker which shows Laserglow's measurements:

sticker.jpg


Laserglow claimed an average power of 133mW, and a peak of 140.4. Not bad, and certainly right in the middle of their spec as stated.

This pre-shipment rating can be helpful for people who are buying and don't have a LPM; Not all companies test and meter their lasers before shipping. But how accurate is their rating? Let's find out.

POWER - RADIANT ALPHA:
6-radiant.jpg

The Radiant Alpha climbs up over the first 20 seconds or so and steadies at 158mW. Not bad, considering that Laserglow metered it quite a bit lower. But, since laser power meters do vary, it's always good to get a second opinion. So, on to the Kenometer...

POWER - KENOMETER PRO:
5-kenometer.jpg

Well, either both of my meters are wrong in the exact same way, or this laser is a good 25mW over the spec of even their own rating. The Kenometer puts it at an average of 158mW, which agrees exactly with the Radiant. It shows a peak of 177mW, which is nearly at Laserglow's peak spec for the Polaris-100. "Instantaneous" readings, as seen on the top, were moving between 154-160mW, which is decently flat and typical of a diode laser.

Note, the light looks purple in this picture. It is not. Trust me, that the light from this laser is a pure and deep blue. Cameras often have trouble capturing lasers in the violet-to-blue spectrum accurately. Many 405nm violet lasers will show up blue, and many blue 445nm lasers will show up violet. This depends on a lot of things, like white balance and color temperature settings, and sometimes the way that the sensor on your camera was built in the first place.

BEAM CHARACTERISTICS:

And now, on to the meat of this review - the beam characteristics.

Once again, Laserglow assured us that the powers of the Polaris at and below 400mW do indeed use corrective optics. But a lot of people have wondered about the nature of these optics, and how well they really do shape and form the beam.

BEAM PROFILES:
7-beamprofiles.jpg


Here we have a shot showing the beam shape at three different distances; 15 feet, 30 feet, and 50 feet. (50 feet is the maximum I could go in my house at the moment.)

A shot I could not show, was right out of the aperture. At the aperture the beam is round, but displaying multimode patterns similar to a multimode HeNe (and almost exactly the same as my multimode green HeNe.) But the output at the aperture is almost perfectly circular, albeit multimode.

As you can see, at 15 feet, the beam starts out elliptical but not too bad - still mainly round, in the photo. Note that in actuality the brightest part of the beam was almost perfectly round - about 7.2x7.9mm. Most 445nm lasers we've seen have shown a square beam profile at this distance.

Moving to 30 feet, the beam is still pretty much round. At this point, most uncorrected 445nm lasers would show a line, not a dot. Optical artifacts around the beam (which are present in all lasers, really) - are gaussian and elliptical, not linear as we've seen in builds with 405-G-1 or Aixiz 445 lenses. This shows that the beam likely is being corrected with true optics and not just a "cut off" cylinder which chops off edges of the linear beam.

And then, moving to 50 feet, the beam gets a bit more elliptical, but still nowhere near the long line we'd see at this distance from your average uncorrected 445nm laser.

While I don't have much more than 50 feet of linear real estate at the moment, Justin from Laserglow did send me a picture of the beam shot at 120 feet. This is not my photo, and I was not able to take any direct measurements for it, but I'll provide it here in the review to give people an idea of the distance it takes for this beam to spread out.

C.JPG

In relation to Justin's hand, at 120 feet, a dot this size in shape is, at least in my opinion (yours may vary) not very bad at all - especially for the linear profile we're used to from 445nm.


COMPARISON

To give an example of how this laser compares to an uncorrected 445nm laser, I put it up against the Wicked Lasers Spyder-3 Arctic, with the arctic on Low mode to compare apples to apples. My arctic outputs about 100mW on low, compared to 158mW with the Polaris-100.

COMPARISON - POLARIS vs ARCTIC:
8-polaris-vs-arctic.jpg

This comparison is at a distance of 30 feet.

As we can see, even on low power (where the diode behaves better), the Arctic clearly outputs a line-shaped beam, whereas the Polaris outputs a round dot.

Notice once again here the beam artifacts. On the Arctic, they are linear. On the Polaris, they are circular.

DIVERGENCE CALCULATIONS

Of debate recently was Laserglow's rather impressive claim of 0.9mRad average divergence on this laser. Divergence, for those who may be new to the hobby, is essentially the rate at which a beam widens over a distance -- the lower the number, the less "flashlight-like" and more "laser-like" the beam is.

0.9mRad is on the order of some of the better DPSS lasers out there; the low "1's" are considered good, anything below 1.0 is considered great.

So how does it measure up?

Since this is an elliptical beam (one side a bit fatter than the other), and Laserglow states 'average divergence', we need to calculate divergence twice, and then get average divergence from that.

First a measurement is taken at two distances, on the "slow axis" (the shortest chord diametrically across the beam's width) and then a measurement is taken at the same distances on the "fast axis" (the 'longer' or 'fatter' width of the ellipse.)

This is what we get:

Code:
...............[B]15FEET....30FEET[/B]
[B]SLOW AXIS : [/B]   7.15mm      9.7mm 
[B]FAST AXIS :  [/B]  7.90mm     12.7mm

I'll provide the actual equation to calculate laser divergence in milliradians (mRads) here:

Divergence = 2arctan(Df-Di/2l)
(Df = second diameter measurement)
(Di = first diameter measurement)
(l = distance in centimeters)

However, for the purposes of this review I'll use http://www.pseudonomen.com/lasers/calculators/mRadCalculator.html, linked here.

The first result I get by calculating the slow axes at 15 and 30 feet:

Code:
At 15 feet, the beam's diameter is 7.15 millimeters.
At 30 feet, the beam's diameter is 9.70 millimeters.
----------------------------------------------------
Divergence of: 0.5577 mRad on the slow axis.

The secont result I get by calculating the fast axes at 15 and 30 feet:

Code:
At 15 feet, the beam's diameter is  7.90 millimeters.
At 30 feet, the beam's diameter is 12.70 millimeters.
----------------------------------------------------
Divergence of: 1.0499 mRad on the fast axis.

To get the average divergence, we use (slowmRad+fastmRad)/2.

Code:
0.5577+1.0499 = 1.6076

1.6076 / 2 = 0.8038

So, we show an average divergence of around 0.8mRad, even better than Laserglow's specified 0.9mRad.

Even if my distances and sizes are slightly off, this is well within claimed spec even with some error. Visually, this is actually one of the most non-divergent lasers I have; being exceeded only by my Laserglow Aquarius-Pro (PGL-III-A) 473nm DPSS laser. It exceeds or matches the divergence of most of my 532nm DPSS lasers.

VISIBILITY:

At this power, and at 445nm, a lot of people may be concerned with visibility. After all, we all know that 555 is the center of human vision -- the most "visibility per milliwatt", and that wavelengths in either direction (towards blue or towards red) fall off in visibility from there.

One might think that this means that a 150mW 445nm laser appears very dim.

I can assure you that this is not the case

150mW of 445nm - VISIBILITY AT NIGHT
9-visibility.jpg


Tonight is a clear winter night in Colorado. We're about to go watch the lunar eclipse. When I took my Polaris-100 outside, I was actually VERY pleasantly surprised at how vividly visible the beam is!

Part of the reason for this is, in laymans terms: while 555nm green may be the peak of our vision during the day (called 'photopic vision'); at night, the center of our vision actually shifts towards blue. This is called 'scotopic vision', and centers around 506nm. When the eye is seeing scotopically, 150mW of 447nm may appear almost just as bright as 150mW of 532nm.

bjo582906.fig1.gif


(Note, that while versions of this graph have been around from time to time on LPF, additionally there is also 'circadian photoreception', tied into the body's day/night rhythms, which shifts the human photosensitive center even more towards blue -- to 460nm -- almost exactly where our 447nm laser is.)

So, in some cases, especially at night, 445-447nm may be nearly as visible as, and possibly more visible than 532nm green. Visually, this laser can be described as anything but "dim". It is quite visible, both in spot shots, and the beam at night even in clear air, is very striking.


CONCLUSION:

Well, besides a reaffirmation of my note that "power isn't everything", I'm very happy with this laser, even if it did cost me a bit more on the 'power-for-dollar" scale than other 445nm lasers that are available.

It's the first 445nm beam of this quality that I've seen, and the divergence and beam shape, combined with power in a blue laser that we'd have killed for at this price a few years ago -- I really do have to take its performance as a whole, and the Polaris really does earn a place in my collection of more 'unique' lasers.

If you aren't worried about beam shape or beam profile, and aren't worried about divergence (and just want to focus the beam to a burning point), there are probably better 445nm lasers for your money.

But if you want one of the highest quality 445nm beams around, with no worry about duty cycle whatsoever, built in a solid host -- and you want to get it without having to worry about customs and support heartache -- I'd really consider the Polaris. Even at the price, I have no regrets.

Thanks for reading.
 
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Great work on this review aryntha! I have seen few reviews so well written!

btw, if you ever get tired of this unit... ;) -Glenn
 
Powers above 400mW do not include corrective optics.

That's really too bad. I don't see how Laserglow can justify charging $1K for their 1W model when it doesn't include any corrective optics. :thinking:

I'm curious what the divergence is for the 1W model.
 
Thanks a lot, Glenn. :) I actually like it a lot more than the Arctic, by quite a bit. It's great to be able to shine that vivid blue without having to worry about blinding neighbors, pets, and children. :)

romogracie: Justin would probably be the best to answer that. I believe the site claims 0.9mRad for all models. I'm not sure that the 1w model from Laserglow is simply a naked 'line' like the Arctic; Justin simply told me that the beam profile changes above the 400mW models.
 
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Very nice review Matt and a special thanks to you for your divergence measurements!

At least LASERGLOW really uses correction optics. I see that there is the Polaris-200 with a listed output power between 200-499mW as substained. There is no Polaris-400 like you told in your review. I´m interested if some of the Polaris-200 are corrected, and those >400mW not? :thinking:
LASERGLOW should clearly say that NOT the whole Polaris series has a 0.9mrad divergence.
I believe and see that LG´s customer support is outstanding, but at these prices I also expect a lot.

+rep for great review :)
 
Whoops, sorry, yes,okay - Edited that, Phi; thanks for the heads up on that.

Would have to wonder, I would guess because of the limitations, if a diode is putting out >400mW in a Polaris-200, they would have to go uncorrected, but this is just a guess. Maybe Justin could chime in here and clarify that.

In his email to me, he worded it like this: "The Polaris series over 400 mW will not be this good since we can’t afford to waste power on filtering and optics, but anything lower than 400 mW will be similar to this."
 
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Thanks for the review! I'm glad that you're pleased with the Polaris.
 
If I can ever get my mitts on one, I'd love to run it through my ProMetric beam cross-sectional analyser and then compare the resulting charts with the beam cross-sectional analyses of my Arctic. :)
 
That pic of the polaris' dot profile next to the arctics speaks volumes, i could care less about raw power when you get a beam like that.
 
Excellent laser you have there! Thank you for sharing all this nice info about it with us.

That dot, and that divergence were all you needed to mention to convince me that you have a nice laser.
 
Very good review. They should put you on the payroll after this review!
+1
 
Heh, thanks. And I wish. I'm sure everyone on LPF would love to be in such a position. And I'd be perfectly happy to take my pay in lasers alone -- but that's sure not gonna happen :)

I've paid for all of my lasers -- I know some folks here do end up with 'review units'; but I don't know how that happens! It's pretty much a "Don't call us, we'll call you" situation I'm guessing...

I try to go after unique lasers, things that aren't all that common. The Polaris did fit the bill on that, since everyone was running madly after power; this was something a bit different.
 
I would like to update this thread real quick.

I just received my Hydra from Laserglow and on the website it states that it is Near TEM00, but multimode. This should be a dot and not a bar right? Mine is a bar.

-Alex
 
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