Review of the Mystery Violet Laser Pen

[The_LED_Museum]

Mystery Violet Laser Pen, retail $(Unknown)

Manufactured by: (Unknown)
Last updated 03-11-21

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The Mystery Violet Laser Pen (hereinafter, probably just called a violet diode laser) is a violet-emitting, directly-injected laser. That is, it produces violet laser radiation directly, without the need for messy, fragile nonlinear crystals like those 532nm green laser pointers and the amberish-yellow and 473nm blue ones as well. It uses two AAA cells -- the same power source used in most other "pen-style" laser pointers and portable lasers.

It is labelled to have an output of 5mW of laser radiation at 405nm; it has a spectrographcally measured wavelength of 406.8nm and a measured power output of 44mW.

It comes in a handsome brass body with a black finish and chrome colored bezel, tailcap, and pocket clip.

SIZE

To get the laser to turn on, first be certain that there are a pair of AAA cells installed. If there isn't, then install them (see directly below), and THEN you can go irradiate something.

Aim the laser well-away from your face first.

Press & hold down the button on the barrel for as long as you want or need the laser spot, and release pressure on the button to turn the laser back off.


To change the batteries in this violet laser , unscrew the laser near the center, and gently place the upper portion down.

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, button-end (+) positive first. This is the opposite of how batteries are installed in most flashlights, so please pay attention to polarity here.

Screw the front portion of the tube back on, and be done with it.

Unable to mesasure current usage due to how the laser was constructed.

Does this evaluation look an awful lot like the one I made for this laser?
Thought you'd say so.
That's because they're functionally, electrically, and physically very similar, so I was able to use its web page as a template for this one.

Beam photograph of this laser on a wall at ~12".
Beam image bloomed ***SIGNIFICANTLY***.
I deliberately photographed this in somewhat low daylight to help reduce image blooming!!!
However as you can plainly see, considerable image blooming did occur!!!


That white & blue color does not really exist; the spot appears to be a very deep royal purple to the eye.
Digital cameras have a tough time at these wavelengths.


And yes, I know that the colors purple and violet are two different critters, but the phrase "royal violet" would not make very much sense; however, most everybody knows what "royal purple" looks like.

Purple is a mixture of red & blue; violet is a spectral color, encompassing wavelengths of ~390nm to ~420nm.

Beam photograph on a wall at ~10'.
Again, that white & blue color does not really exist.

Power output measures 44mW on a LaserBee AX laser power meter.

The beam appears to have a focus slightly beyond infinity (the lens is just a skosh too close to the diode) so the beam appears larger in diameter at aperture and has no "waisting" as you might see with most other "pen-style" lasers.

Spectrographic analysis of the Blu-ray laser diode in this product.
Wavelength appears to be ~405nm, which is within specification for the type of laser diode used in this laser.

Same as above; but spectrometer's response narrowed to a band between 400nm and 410nm.
This shows that the wavelength is 406.8nm -- right about where I eyeballed it prior to spectroscopy.

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at br53.txt

USB2000 Spectrometer graciously donated by P.L.

A beam cross-sectional analysis would normally appear here, but the ProMetric System that I use for that test was destroyed by lightning in mid-July 2013.

​

TEST NOTES:
Test unit showed up meowing in my mailbox totally unannounced late on the morning of 03-10-21.

I have decided to rate this little laser three stars.
The only real reasons that it did not receive five stars is because the claimed power output and the measured power output vary so greatly (claimed at <5mW, measured at 44mW) -- a rather severe no-no and because it is mislabelled which is also another no-no -- actually that's a HELL NO!!!


UPDATE 00-00-00:


PROS:
Color is very radiant & unusual for a handheld laser
Uses inexpensive and readily available batteries
Color is very radiant an unu...o wait, I said that already!!!

NEUTRAL:

CONS:
Just the usual suspects for laser modules/pointers - nothing that affects rating...actually, there is one little thing: it is labelled as a 5mW laser, but outputs a measured 44mW of laser radiation.
That's what nocked most of the stars off.

MANUFACTURER: Unknown
PRODUCT TYPE: Violet-emitting diode laser
LAMP TYPE: Sony Blu-ray laser diode
No. OF LAMPS: 1
BEAM TYPE: Very narrow spot
SWITCH TYPE: Momentary on/off button on barrel
CASE MATERIAL: Brass
BEZEL: Metal; laser & lens recessed into a hosel for them in its end
BATTERY: 2x AAA cells
CURRENT CONSUMPTION: Unable to measure
WATER-RESISTANT: Light splatter-resistant at maximum
SUBMERSIBLE: No
ACCESSORIES: None
SIZE: 153.30mm L x 14.10mm Dia. (not incl. button or pocket clip)
WEIGHT: 39g (1.38oz) incl. batteries; 16g (0.56oz.) empty
COUNTRY OF MANUFACTURE: China
WARRANTY: Unknown/not stated


PRODUCT RATING:

 

[CurtisOliver]

I’ve always liked how in depth your reviews are. Even on a eBay pointer. Nice job.

 

[Encap]

Excellent review

 

[bulukaki]

Interesting review, I just found a local seller (Taiwan) that sells one that is labeled as <40mW. It might use the same diode, who knows.

There's no laser power restriction here in Taiwan, but most sellers seem to just parrot the original alibaba listing or wherever they got their laser from, with the power rating ranging from the cliche "<5mW" to the preposterous "5000MW".

 

[julianthedragon]

Nice review! Just got a similar laser as a gift. Something interesting--in addition to violet being a spectral color, another difference between violet and purple is that purple usually contains close to a 1:1 ratio of blue to red while violet is dominated by blue and only has a little red. If you look at this graph of RGB presence over the visible spectrum you can see a little bump in red near the violet end of the spectrum.

 

[FireMyLaser]

The graph you see is the colour mixing which a typical person would use with three RGB primary colors of specific wavelengths. The ratios show how get the closest match to the pure spectral counterpart, not necessarily creating a 1:1 replica.

 

[CurtisOliver]

Yes, there is a difference between a pure wavelength and that of wavelength mixing.

 

[julianthedragon]

Maybe I wasn't careful enough with the way I phrased it, but I was referring to the way the cones in our eyes and the RGB sensors in a digital camera perceive color. Yes there is a fundamental difference between the spectral color and mixed red and blue but it's true that violet stimulates mostly blue receptors, a little red, and a very small amount of green that we seem to ignore. https://jakubmarian(.)com/difference-between-violet-and-purple/ This is an article that explains better than me.
PS. I've been lurking this forum for years but only made an account and started using it recently, so I'm open to criticism and I'm still getting the hang of it/meeting people. Nice to finally interact with you guys

 

[FireMyLaser]

How we see and understand colors is very complex, and perhaps not many here knows it. The cone response is just one part of it. A lot more happens in the brain.

This is the cone response:


If our brain would take this and not do any addition processing, then we would have a hard time telling colors apart. We really "see" things in our mind in the end. Our eyes are so separate from the brain that we can "hack it" to perceive deeper colors than our eyes can achieve on their own.


Stare at the image above until the red gets dull and then close your eyes. You will then see true cyan without light.

 

[julianthedragon]

Thanks, that info is fascinating along with the "hack" to see a deeper cyan. I brought it into photoshop to see if I could recreate what I saw (obviously couldn't) and also switched around the hue to see if it would work with other colors.

 

[FireMyLaser]

In theory you cant even see cyan that deep with a perfect laser. I'm not going to claim it definitively, but that basis is that our eyes have limitations. Cross-talk, light leakage etc, skews what we see from reality. And the deeper you explore these topics, the more it will crossover into philosophy.

 

[CurtisOliver]

I have noticed that I only see RGB cyan with my lasers when I have used a higher wavelength laser prior.

 

[icecruncher]

Nice review, I have owned quite a few of these with ranges all the way up to near 100mw. Only other thing of note is that on SOME of these, if you pull the cap, there is an adjustable screw in lens that is a standard AixiZ style. However, some also had a fixed lens.

I've made a few cheap burners out of these by adjusting the lens. The beam is tight enough and strong enough on some to be able to light matches, pop balloons and so forth. not bad for the very inexpensive price, IMHO.

 

[hakzaw1]

why would a 532 penpointer appear yellow rather (to our eyes) than green in the 'presence' of an Argon ?-
We all saw this-- when the Argon stopped the pointer was back to 'normal' green. cameras did not catch this--will exercise my Argons soon -and try to see this again...back then that pointer was $40 and my first green.. it was abused (my bad--no rest cycles) and died.