# Review of a Rigel DPSS yellow laser pointer



## The_LED_Museum (Jul 14, 2007)

Like I did with another yellow DPSS laser, two blue DPSS lasers, and two violet directly-injected lasers...since some people cannot view my website, I offer this on CPF to benefit such people:
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*Rigel Yellow Laser Pointer, retail $299.00 (www.laserglow.com...)
Manufactured by (Unknown) for Laserglow Technologies (www.laserglow.com)
Last updated 05-16-09
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(In reference to the small package I received from Laserglow at 1:29pm PDT on 07-13-07):
{_sung like the Foreigner song "Feels Like the First Time"_}





This is the Rigel, a yellow DPSS laser in a pen-style body. This is only the second yellow laser I've seen; this was the first, and that one was received in very late-summer 2004.

It generates an amberish-yellow beam, measured spectrographically at 592.95nm (5,929.5Å); just a bit longer in wavelength than the sodium line at 589.2nm (5892.0Å). The color could best be described as a "_very_ strong urine yellow"; though there are probably some more gentle terms that could be used to describe the color - like...er...uh..."_sunset_ yellow".





The output power is stated as "0.6mW to 2.0mW"; this was measured in this particular unit at 1.8312mW.

It uses a mechanism similar to that used by green laser pointers: an infrared laser diode is fired into a crystal of material that lases at two longer wavelengths in the infrared, who's light is then fired into a frequency-doubling crystal, producing the yellow laser beam you see. This is known as DPSS (Diode Pumped Solid State).

It comes in a brass body, and feeds from two AAA cells.







SIZE






To use your shiny new (or corroded old)



Rigel, first peel off the orange plastic piece off the "business-end", and install two AAA cells (see directly below) that you furnish yourself.

At this point, just aim it at something you wish to point out, and rather firmly press & hold down the button on the barrel for as long as you need the laser spot.
Release the button to turn the laser pointer back off. Yes, it really is as easy as that.

It comes in a white cardboard box with a foam insert that the laser fits into; and although in and of itself this is not a storage case, with minor modification to the foam, it will fit many storage cases designed for green DPSS lasers. Otherwise, just store your Rigel in a clean & dry location, and it should not give you any guff.







To change the batteries in your Rigel, unscrew and remove the tailcap, gently place it on the ground, and kick it into the garden so the hungry, hungry praying mantids will think it's something yummy to eat and subsequently strike at it...O WAIT!!! YOU'LL NEED THAT!!! So just set it aside instead.





Tip the two used AAA cells out of the barrel and into your hand, and dispose of, recycle, or recharge them as you see fit.

Insert two new AAA cells into the barrel, flat-end (-) negative first. This is the opposite of how batteries are installed in most flashlights, so please pay attention to polarity here.

Screw the tailcap back on, and be done with it.
Aren't you glad you didn't kick that tailcap into the garden with all those hungry, hungry praying mantids now?









Here is what a praying mantis looks like.
I found this guy on the morning of 09-08-06 clinging to the basket of my scooter.

Current usage measures 475mA on my DMM's 4A scale.


There is a sticker on the box with the following text on it:

*WARNING: BATTERIES GO IN THE BACK
OF THE UNIT. DO NOT ATTEMPT TO
REMOVE THE "HEAD" AS THIS WILL
VOID YOUR WARRANTY.*​




This is a laser pointer, not a flashlight. So I won't throw it against the wall, stomp on it, try to drown it in the toylet bowl or the cistern, run over it, swing it against the concrete floor of a patio, bash it open to check it for candiosity, fire it from the cannonada (I guess I've been watching the TV program "Viva Piñata" too much again



- candiosity is usually checked with a scanner-type device on a platform or a handheld wand), send it to the Daystrom Institute for additional analysis, or inflict upon it punishments that flashlights may have inflicted upon them. I almost never beat, hit, throw, stomp on, or otherwise attempt to destroy lasers or other products which lase, because of their inherent delicacy. Therefore, this section of the laser's web page will seem a bit more bare than this section of the web page on a page about a flashlight.

Yellow diode lasers are a lot different than those common red lasers you see all the time.

In a 640nm red laser pointer, there's a red-emitting diode and a lens to collimate (focus) the beam.

In a 593.5nm yellow DPSS laser (pointer or larger size), there's a BIG infrared laser diode that generates laser light at 808nm, this is fired into a crystal containing the rare-earth element "neodymium". This crystal takes the 808nm infrared laser light and lases at 1,064 and 1,342nm (yes, deeper in the infrared!). This laser light comes out of the Nd:YV04 (neodymium yttrium vanadium oxide) crystal and is then shot into a second crystal (containing potassium, titanium, & phosphorus, usually called KTP) that roughly doubles the frequency to 593.5nm - the bright orangish yellow color you see. This light is then collimated (focused) by a lens and emerges out the laser's "business end". Just before the lens, there's a filter that removes any stray NIR (near-infrared) and IR (infrared) radiation from the pump diode and the neodymium crystal. You don't want that stuff in your yellow beam, trust me.





From a laser engineer who emailed me about this laser, comes the following text:
_
The technology behind the yellow laser is a bit more involved than in the green laser, involving a process called sum frequency generation. It uses the same components that the green laser has, but the coatings are much different.

There are two particular "tricks" in making a sum frequency laser. The first is to get a single laser crystal (the Nd:YAG or Nd:YVO4) to lase simultaneously at two different wavelengths, both 1064 nm and 1342 nm. While we do this with gas lasers (Argon and Krypton) frequently, this is pretty rare with solid state. The relative powers of the two have to be in a reasonable range for the sum frequency process to work. The two waves are introduced in to the KTP crystal, which generates the 593.5nm output._

This is why yellow DPSS lasers are so much more expensive than red diode lasers. Lots of itty bitty parts, and they all need to be very carefully aligned by hand. If the polarisation is "off", one or both crystals need to be turned.
With red diode lasers, you just slap in the diode and slap a lens in front of it. 

This unit is not waterproof or submersible, so please try not to drop it in creeks, rivers, ponds, lakes, oceansides, docksides, steaming (or cold) puddles of arctic wolf pee, slush piles, mud puddles, tubs, toilets, sinks, fishtanks, dog water dishes, or other places where water or water-like liquids might be found. In fact, because of its delicacy, please try not to drop it at all, regardless of whether the place is wet or dry.
I don't have any idea about how to resurrect a flooded DPSS laser, so if it got douched, you're probably SOL.





The end cap can be unscrewed to facilite cleaning of the lens; however this also removes the IR filter. This was evident because a thin square of bluish-green glass was seen inside the end cap. Here, let me show you with a photograph...snap...flash...click..and it's off to the Fotomat we go:






The amount of IR radiation emitted by this laser without the filter is surprisingly small; please see the third spectral analysis chart on this web page to see for yourself.
Normally I'd raise a stink about the IR filter being easily removeable by the end-user, but the amount of IR radiation emitted in this case is *SO LOW*, I don't feel the need to make a big issue of it.

The Rigel is true CW (continuous wave), not quasi-CW or pulsed. I verified this two ways: I rapidly waved it around to see if a broken line appeared (it did not), and I tested it with an oscilloscope to detect pulsed operation at faster speeds than an optical detection method can reveal, and again, found no evidence of pulsed operation.

I've noted that the button on the Rigel is harder to press than it is on all other laser pointers I've used to date. This is not necessarily a bad thing, but it is noticeable.

This is a CDRH Class IIIa laser product, so it is kosher for me to call it a "pointer", rather than a "module".

The warranty is rather specific: in the instructional material furnished with the laser is the following:

*The unit is guaranteed to operate within specifications for 6 months from the shipping date, provided that:*

- No modifications have been made to this unit.
- The unit has not been disassembled or tampered with.
- The unit was not dropped or subjected to excess shock or static electricity.
- The original instructions and warranty with serial number is retained.
- The unit is not operated from any power source other than 2 type "AAA" 1.5V Alkaline batteries.







Beam photo at ~12".
Beam spot is *significantly smaller* than it appears; the beam image bloomed quite a bit.
Power output measures 1.8312mW on a laser power meter.






Beam photograph on a wall at ~10 feet.

Those rectangular graphic things near the center of this photograph are marquees from:

Nintendo ''R-Type''
Super Tiger...er...uh...Konami ''*Super Cobra*''




Midway ''Omega Race''
Sega ''Star Trek''
Williams ''Joust''
Venture Line ''Looping''
Universal ''Mr. Do!'s Castle''
Jaleco ''Exerion''
Gremlin/Sega ''Astro Blaster''
Atari ''Tempest''
Gottlieb ''Q*bert''

upright coin-op arcade video games from the 1980s.

And that graphic toward the right is:
A "*BIG SCARY LASER*" poster sent by www.megagreen.co.uk






Photograph of the beam on a wall at ~10 feet, with a Wicked Cap (magnifying lens) from my Pulsar on it.
Yes, I said *MY* Pulsar, as I purchased it myself.










Spectrometer plot of this laser.






Spectrometer plot of this laser, with spectrometer's response narrowed to a range of 588nm to 598nm.
Wavelength appears to be 592.95nm; spectral line halfwidth appears to be ~1.7nm.






Spectrometer plot of this laser, with end cap (IR filter) removed, showing
only minimal amounts of 808nm laser radiation from the pump diode.






Spectrometer plot of this laser, deliberately "overexposed" to show the weak 532nm and 671nm laser lines.






Attempted spectrographic analysis of fluorescence of a Tritium Torch when irradiated with this laser.
I was kind of hoping to see anti-Stokes emission centered at ~750nm.

Ocean Optics USB2000 Spectrometer graciously donated by P.L.


​*TEST NOTES*:
Test unit was purchased from Laserglow Technologies on 07-09-07, and was received on 07-13-07.




*UPDATE* 07-14-07:
Power output measures 1.6524mW when this laser is fed with known-new Energizer L92 lithium AAA cells.
According to the warranty info, I really need to get those lithiums out of there!!!



*UPDATE* 08-25-07:
I have decided to derate this product ***SLIGHTLY*** because the button is a bit harder to press on than the buttons of all other lasers I've tested. It still stays in The Trophy Case, however its rating has been changed from 5 stars to 4½ stars.




_*PROS*_:
Uses batteries that are common and relatively inexpensive
Unique, attention-getting color that's radiant and unusual for a handheld laser
Beam is "clean", with no visible speckling or artifacts around it
Unique, attention-getting color...o wait I said that already.






_*CONS*_:
Fragile interior construction - like all DPSS lasers. Will not figure into my rating
Not water-resistant - but most other DPSS lasers aren't either. Will not figure into my rating
Button is exceptionally difficult to actuate 




*

MANUFACTURER: Unknown/TBA 
PRODUCT TYPE: Yellow-emitting laser pointer 
LAMP TYPE: DPSS laser 
No. OF LAMPS: 1 
BEAM TYPE: Very narrow spot; it's a laser, remember?




SWITCH TYPE: Pushbutton momentary on/off on barrel 
CASE MATERIAL: Brass 
BEZEL: Metal; has aperture (hole) for laser beam to emerge 
BATTERY: 2x AAA cells 
CURRENT CONSUMPTION: 475mA 
WATER RESISTANT: No 
SUBMERSIBLE: No 
ACCESSORIES: None 
WARRANTY: 6 months 


PRODUCT RATING:








*







_Rigel Yellow Laser Pointer * www.laserglow.com..._​


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## comozo (Jul 14, 2007)

*Sum frequency* is the term that describes how a laser like this generates light at that wavelength


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## knot (Jul 14, 2007)

Are the green ones the only ones with a visible beam or is this also visible at night?


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## The_LED_Museum (Jul 14, 2007)

This laser's beam is also visible at night or in subdued lighting, with similar parameters on how you would see a green laser's beam (smoke, fog, or moisture in the atmosphere).


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## knot (Jul 14, 2007)

Are the green ones the only ones with a visible beam or is this also visible at night?


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## The_LED_Museum (Jul 15, 2007)

*BTTT* (*B*ash *T*elephone *T*ub *T*ree) Update on 07-15-07: Added explicit warranty information for the Rigel.


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## The_LED_Museum (Jul 16, 2007)

*BTTT* (*B*ash *T*elephone *T*ube *T*ester) Update on 07-16-07: Added a beam photograph.
Rise and shine CPF! It's 0618 hours! Early bird gets the gagh!


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## The_LED_Museum (May 16, 2009)

*BTTT*: Added a spectrographic anaysis.


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