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



Review of the Mini Purple Class Laser Beam Black Keychain

The_LED_Museum

Active member
Joined
Nov 1, 2006
Messages
513
Points
43
This is a long page with at least 20 images on it; dial-up users please allow for plenty of load time.
Somebody set up us the bomb.


Mini Purple Class Laser Beam Black Keychain, retail $7.99
Manufactured by: (Unknown)
Last updated 11-26-10



The Mini Purple Class Laser Beam Black Keychain 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 green laser pointers and the amberish-yellow and blue ones as well. It uses a a single AAA cell -- not two AAA cells like most other "pen-style" laser pointers and laser modules do.

It is advertised to output 5mW of laser radiation at ~405nm.
It actually measures 23.110mW at 401.10nm!!!

It comes in a handsome brass body with a black finish and chrome colored bezel, tailcap, and spring-loaded "lobster claw" keychain attachment.




SIZE



To get the laser to turn on, first be certain that there is an AAA cell installed. If there isn't, then install it (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 battery in this violet laser , unscrew the tailcap, and set it aside.

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

Insert a new AAA cell 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.


Measures 134.60mA on my DMM's 400mA scale.





This is a self-contained laser , and not a flashlight meant to be carried around, thrashed, trashed, and abused - so I won't abuse it in the name of science like I might abuse a flashlight.
Lasers are meant to be loved, not punished!!!


This is a directly-injected laser, who's active components are the inverter circuit, the laser diode, and the collimating lens. So it should withstand accidents better than a DPSS (diode pumped solid state) laser - the type of laser assembly found in yellow (593.5nm), green (532nm) and blue (473nm) laser pointers. These lasers have several additional components (crystals, filters, etc.) in the optical train, and you can knock them out of alignment by doing little more than looking at them the wrong way. And if any of these components are knocked out of whack, you'll no longer get your yellow, green, or blue laser beam.

Though you still do not want to intentionally drop your violet-emitting laser because it's a precision optical instrument.

Although there is a label on the unit advertising its output power as "(30-50)mW", there is no CDRH classification shown; eg. it does not read "Class IIIb" as it should.
This is rather expected of a product of non-US origin; sometimes known as the "Hoo Phlung Pu" brand.







Beam photograph of this laser on the test target at 12".
Beam image bloomed ***SIGNIFICANTLY***.
I deliberately photographed this in somewhat low daylight to help reduce image blooming!!!

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 ~410nm.

Measures a rather hefty 23.110mW on a Sper Scientific Pocket Laser Power Meter # 840011; using known-new Duracell AAA cells.


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

Those colored graphics toward the left are my "Viva Piñata" posters, and that clock on the right that looks like a gigantic wristwatch is my Infinity Optics Clock.
You may also be able to see one of my SpongeBob SquarePants plush (Squidward Tentacles) and a Digimon plush (Greymon). Normally, a Patrick Star plush (from SpongeBob) would be hanging next to Squidward, but he was down here at the spectrometer for a test of his own.





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 390nm and 410nm.
This shows that the wavelength is 401.10nm.



Spectrographic analysis of the fluorescence of a uranated* glass marble when irradiated with this laser.



Spectrographic analysis of fluorescence of the 2009 NIA Commemorative Insulator in uranated* glass when irradiated with this laser.

*"Uranated" - infused with an oxide anion of uranium, *NOT* piddled (peed) on.

Commonly referred to as "Vaseline glass" because it has
a distinct pale yellow-green color when not being irradiated.


Note spelling: "urAnated", not "urEnated","urInated",
"urOnated", "urUnated", or sometimes "urYnated".

USB2000 spectrometer graciously donated by P.L.




Beam cross-sectional analysis with beam widened (x-axis).



Beam cross-sectional analysis with beam widened (y-axis).

These charts show the somewhat ovoid beam profile;
this is consistent with directly-injected diode lasers.

Images made using the ProMetric System by Radiant Imaging.






TEST NOTES:
Test unit was purchased on Ebay on 10-06-10 (or "06 Oct 2010" if you prefer), and was received at 5:23pm PST on 11-22-10 ("22 Nov 2010").

I have decided to rate this wonderful little laser five stars!!!




UPDATE: 00-00-00



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

Properly labelled for power output


CONS:
Just the usual suspects for laser modules/pointers - nothing that affects rating





MANUFACTURER: Unknown
PRODUCT TYPE: Violet-emitting 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 its end
BATTERY: 1x AAA cell
CURRENT CONSUMPTION: 134.60mA
WATER- AND URANATION-RESISTANT: Light splatter-resistant at maximum
SUBMERSIBLE: For Christ sakes NO!!!
ACCESSORIES: Short chain with spring-loaded "lobster claw" clip, hard-sided storage case
COUNTRY OF MANUFACTURE: China
WARRANTY: Unknown/not stated

PRODUCT RATING:



 
Last edited:



HaloBlu

New member
Joined
Dec 27, 2009
Messages
1,327
Points
0
Took over 6 months for anyone to comment?!
Love highly detailed reviews. Read many reviews on your site, didn't know you had an account here.
 

BKarim

New member
Joined
Jan 4, 2010
Messages
164
Points
0
"Generally nimh will not provide the same performance"

even with an good driver (that seems not to be here) ?
 

InfinitusEquitas

Well-known member
Joined
Mar 27, 2011
Messages
15,580
Points
113
If you're looking at a laser with a good driver.. it won't be running off of AAA's;)

For the one you ordered, you can try tossing a 10440... may kill it, or may not. I usually do with all the cheaper greens, but it is a risk.

Besides... we're assuming there is actually a driver, there isn't always..
 

BKarim

New member
Joined
Jan 4, 2010
Messages
164
Points
0
i just tried with two NiMH, and the host is hot now...
what's getting hot: diode or driver ?
 

InfinitusEquitas

Well-known member
Joined
Mar 27, 2011
Messages
15,580
Points
113
Could be three things.. host, diode, batteries themselves.

How long was the laser on for?

Generally those shouldn't be run for more than a minute at a time MAX.
 

BKarim

New member
Joined
Jan 4, 2010
Messages
164
Points
0
20s
the batteries kept cold.

I'm asking: if these violet laser are safe they are too dim to play with, and if they are bright enough they are not safe, isn't it ?
 




Top