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Review of the Directly-Injected 5mW 515nm Green Laser Pen

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Directly-Injected 5mW 515nm Green Laser Pen, retail $75.00
Manufactured by (Unknown)
Last updated 04-10-14



This is a green-emitting diode laser in a pen-style body.

But it's not DPSS (Diode-Pumped Solid State) like those now-common green laser pens -- no, this one uses a new technological advancement that allows green laser radiation to be produced directly, without the need for those messy, fragile nonlinear crystals!

This is the first of these green lasers to have been mass-produced in a totally self-contained "pen" format -- that I'm aware of anyway.

It's rated to produce 5mW of laser radiation at 515nm in the bluish-green part of the spectrum (these values were measured at 8mW with a wavelength of 518nm).

Because this is a laser, you should not shine it into your eyes, other people's eyes, pet's eyes, etc. Just use a little common sense here, k?


SIZE




To use your new Directly-Injected 515nm Green Diode Laser Pen, insert the furnished cylindrical interlock key into the keyway for it in the tailcap (rotate it as necessary until you feel it go in), turn it clockwise (as though tightening it) until it stops, and then pull it straight out. This "arms" the laser.

Press & hold down the button on the barrel for as long as you need the laser spot. A red "emissions indicator" LED will turn on; it is located immediately forward of the switch button. Release the button to turn the portable laser back off. Yes, it really is as easy as that.

If you wish, you may totally neutralise the laser by inserting the furnished cylindrical interlock key into the tailcap (rotate it as necessary until you feel it go in), turn it counterclockwise (as though loosening it) until it stops, and then pulling it straight out. Doing this disables the laser completely, so that it may not be activated even when new batteries are in place.



Photograph showing the cylindrical key, the keyway in the laser's tailcap, and the indicator dots on the tailcap.



To change the batteries in this laser, unscrew & remove the tailcap, and set it aside.

Tip the used AAA cells out of the barrel and into your hand, and dispose of, recycle, or recharge them (rechargeable cells only!!!) as you see fit.

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

Screw the tailcap back on, and be done with it.

Above threshold, current consumption measures 261.30mA on my DMM's 400mA scale.
Below threshold, current consumption measures 45.50mA on my DMM's 400mA scale.

The Directly-Injected 515nm Green Diode Laser Pen is not water-resistant or submersible (it's a laser pen for Christ sakes!!!), so please keep it away from water.

The published specs on this laser pen are as follows:
o Emission Wavelength: 515nm
o M2: <1.20
o Beam divergence: <2.0 mrad
o Beam diameter at aperture: <1.50mm
o Warmup time: <30 sec.
o Transverse Electromagnetic Mode: TEM[sub]00[/sub]
o Operation Temperature Range: 50°F (+10°C) to 86°F (+30°C)
o Storage Temperature Range: 14°F (-10°C) to 122°F (+50°C)
o Operating Current: <265mA
o Operating Voltage: +3.0 volts DC

Below, you'll find my power output and spectrographic findings (both measured with instruments specifically designed for this purpose).



Power output peaks at 8mW.
Batteries for this analysis were purchased just before the test.

This test was conducted on a LaserBee 2.5W USB Laser Power Meter
w/Thermopile
.

I later measured a power output of 4.4625mW on a Sper Scientific Pocket Laser Power Meter # 840011.


Beam terminus photograph on the test target at 12".
Beam image bloomed quite a bit; it also shows a lot of white that doen't exist in the actual beam.



Beam terminus photograph on a wall at ~15 feet.
As with the above photo, the beam image bloomed quite a bit; it also shows a lot of white that doen't exist in the actual beam.



Beam terminus photograph on the side of an uninhabited structure located ~275 feet (~83.82M) away.
The albedo of this structure is somewhere between 92 and 95.


Beam photograph in moderate fog.
Photo was taken at 6:40am PST on 02-02-14.






Beam terminus photographs (while the laser was deliberately being moved) in freshly-fallen snow.
Photographs were taken on the morning of 02-09-14 in Federal Way WA. USA.


Photograph showing that the unit still emits light when you think it's off.

Current usage in this quiescent mode (when the laser should be totally off) was measured at 1.4mA on my DMM's 400mA scale.




Video on YouTube showing the laser's beam terminus spot of the Directly-Injected 5mW 515nm Green Laser Pen being projected onto freshly-fallen snow while the laser itself was being waved about.

VERY IMPORTANT!!!
This video shows what appears to be a dashed line when the laser is being moved. This is due to how the camera records video; in reality, the line is continuous and unbroken!

This video is 142.0947831628 megabytes (142,433,138 bytes) in length; dial-up users please be aware.
It will take no less than seven hundred ten minutes to load at 48.0Kbps.



Spectrographic analysis of this laser.



Spectrographic analysis of this laser; spectrometer's response narrowed to a band between 510nm and 520nm to pinpoint wavelength, which is 518nm.


Spectrographic analysis of this laser; spectrometer's response narrowed to a band between 800nm and 874nm to check for the presence of a pump laser -- which none exists (I irradiated the spectrometer's sensor quite well in effort to capture this!)

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at http://ledmuseum.candlepower.us/44/515point.txt



Spectrographic analysis of this laser below lasing threshold.

Spectrographic analysis of this laser below lasing threshold; spectrometer's response narrowed to a band between 522nm and 542nm to pinpoint wavelength, which is 531nm.

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at http://ledmuseum.candlepower.us/45/bt515poi.txt

Power output in this below-threshold state was measured at 19.830µW (that's microwatts) on a Sper Scientific Pocket Laser Power Meter # 840011.


Spectrographic analysis of this laser when it is "off".

Spectrographic analysis of this laser when it is "off"; spectrometer's response narrowed to a band between 522nm and 542nm to pinpoint wavelength, which is 530nm.

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at http://ledmuseum.candlepower.us/45/of515poi.txt

USB2000 Spectrometer graciously donated by P.L.


A beam cross-sectional analysis would normally appear here, but my poor defenseless helpless innocent ProMetric 8 Beam Cross-Sectional Analyser that I use for that test was destroyed by a nearby lightning strike in mid-July 2013.



In leiu of a beam cross-sectional analysis, I present to you this photograph that shows the ovoid beam profile, which is characteristic of a diode laser -- this clearly shows that it has fast and slow axes.

The distortion along the fast axis was caused by the lens used to widen the beam; it was not properly affixed to the laser's aperture and as a result, it was tilted somewhat. This does not significantly distort the actual beam image, and may safely be ignored in this case.


TEST NOTES:
Test unit was purchased on Ebay on 01-10-14, and was received at 3:51pm PST on 01-28-14.


UPDATE: 00-00-00



PROS:
Very unique beam color -- 518nm is very radiant and unusual
Beam is clean with no unwanted artifacts or speckling in it



NEUTRAL:


CONS:
Power output drops sharply when unit is exposed to cold (or even cool) temperatures




MANUFACTURER: Unknown
PRODUCT TYPE: Pen-style portable laser
LAMP TYPE: Directly-injected green-emitting diode laser, red LED "emissions" indicator
No. OF LAMPS: 2 (1 ea. laser diode & LED)
BEAM TYPE: Very narrow spot -- it's a laser, remember?
REFLECTOR TYPE: N/A
SWITCH TYPE: Momentary pushbutton on/off on barrel
CASE MATERIAL: Metal
BEZEL: Metal; laser diode & collimating lens recessed into hosel for them
BATTERY: 2 x AAA cells
CURRENT CONSUMPTION: 261.30mA (above threshold), 45.50mA (below threshold)
WATER-RESISTANT: No
SUBMERSIBLE: No
ACCESSORIES: Interlock key, hard-sided storage case
SIZE: 193mm L x 14.50mm Dia.
WEIGHT: 85.10g (3.00 oz.) incl. batteries
COUNTRY OF MANUFACTURE: Unknown/not stated
WARRANTY: 1 year

PRODUCT RATING:


Update 02-10-14: Added four photographs and a video of the laser in operation.

Update 02-13-14: Performed spectrographic & power output analyses of this laser below lasing threshold.

Update 02-16-14: Took a current usage measurement while the product was operating below lasing threshold.

Update 04-10-14: Added a photograph showing that the unit still emits light when you think it's off; also performed spectroscopy of this weak emission.
 
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Ears and Eggs

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Awesome review, thanks. Was just considering buying one of these from LaserBTB. :D Need MOAR wavelengths. :D

I believe it is the same as the one LaserBTB sells:

LP 515nm 532nm 1-150

Further down on that page there is a picture of one with a tailcap key that looks very similar to this one.
 
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Cyparagon

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...a wavelength of 517.880nm[/i][/b]).
We've been over this twice before. Your spectrometer does not have that accuracy. It's 518 +/- 1nm at best.

CURRENT CONSUMPTION: 261.30mA
Why are you adding decimal places again? Your meter is not that accurate. And even if it was, the loading of the internal shunt will affect the current draw. Even if you assume a perfect DMM, the current draw changes DRASTICALLY with battery charge level.

I present to you this photograph that shows the ovoid beam profile, which is characteristic of a diode laser -- this clearly shows that it has fast and slow axes.
All single-mode diodes have an output similar to this. This is just an image of the emitter, as the emitter is not circular. It doesn't mean they have fast and slow axis. Does the output look like a line at a distance? If not, it does not have a fast/slow axis.
 
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Hemlock_Mike

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I think I'm missing something here. I have a 100 mW 520 nM
in my pocket that I built. I'm also seeing posts of ~1 W of 520 nM.
Guess I better go back to 1064 !!!!!
HMike
 

Hap

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Nice review! :p

Im thinking of maybe getting 515nm in the near-future since it would fit perfectly in-between 473nm and 532nm, and would give me 1 more wavelength :D
 
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BTTT: Performed spectrographic & power output analyses of this laser while it was operating below lasing threshold.
 
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I ordered and payed for 2 of these at Laserbtb in december 2013. Received one (1!!!) in mid january. Today is february, 20th and still haven't received my 2nd laser (which I payed for!) Have been e-mailing with Laserbtb over and over to no avail yet. The one I did receive has a short circuit in it. When the key is left in the green or orange position, it slowly drains the batt's. You can see it stays on as there is a little weak spec of green light visible inside the diode. Not exactly the kind of service I expected from a company that is profiled as being 'highly reputable' over here, if you ask me...
 

mortuus

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I ordered and payed for 2 of these at Laserbtb in december 2013. Received one (1!!!) in mid january. Today is february, 20th and still haven't received my 2nd laser (which I payed for!) Have been e-mailing with Laserbtb over and over to no avail yet. The one I did receive has a short circuit in it. When the key is left in the green or orange position, it slowly drains the batt's. You can see it stays on as there is a little weak spec of green light visible inside the diode. Not exactly the kind of service I expected from a company that is profiled as being 'highly reputable' over here, if you ask me...
Weird, did you get a tracking number on the second thats not arrived yet you should be able to search the number and see what it says?
 




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