Review of the 405nm Violet Portable Laser w/ Adjustable Focus + Charger

The_LED_Museum · Apr 13, 2014

405nm Violet Portable Laser w/ Adjustable Focus + Charger, retail $20.00
Manufactured by: (Unknown)
Last updated 04-14-14

The 405nm Violet Portable Laser w/ Adjustable Focus + Charger (hereinafter, just called a "violet portable 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 green laser pointers and the amberish-yellow and light blue ones as well. It uses a single 18650 rechargeable lithium cell.

And its beam focus is very easily adjustable by simply turning a ring on the laser's "business-end".

It produces 125mW of laser radiation at a wavelength (spectrographically measured) of 414nm.

This is the reason I call it a "portable laser" on this website instead of a "pointer". Lasers designated as "pointers" must -- by US law anyway -- have a power output that does not exceed 5mW.

It comes in a handsome aluminum body with a black finish.

SIZE

To get the laser to turn on, first be certain that there is an 18650 rechargeable cell installed. If there isn't, then install it (see directly below), and THEN you can go irradiate something.

Insert one of the furnished interlock keys into the tailcap and rotate it approx. ¼ of a turn clockwise (as though tightening it). The key may be left in place or removed at this point.

Now, aim the laser well-away from your face.

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 adjust the focus, turn the knurled ring on the laser's bezel counterclockwise (as though loosening it) to bring the beam's focal point closer to the aperture, and turn it clockwise (as though tightening it) to bring the beam's focus farther away; when it stops turning, the beam is focused to infinity (where the laser beam comes out like what you'd expect to see -- it stays narrow for a decent distance)

When finished using the laser, insert the interlock key into the tailcap and rotate it approx. ¼ of a turn counterclockwise (as though loosening it). Pull the key straight out and stash it away. This completely neutralises the laser so that somebody who might pick it up won't be able to fire it off even if a charged battery is in the barrel.

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

Tip the used 18650 rechargeable cell out of the barrel and into your hand, and recharge it.

Insert a new 18650 rechargeable cell into the barrel, nipple-end (+) positive first.

The normal installation procedure is the opposite of how batteries are installed in most flashlights, so please pay attention to polarity here.

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

Current usage measures 232.0mA on my DMM's 4A scale.

To charge the 18650 cell, insert it into the furnished charger, orienting it so that it's nipple-end (+) positive faces the skinnier end of the charger, unfold the AC prongs on the back, and plug the charger into any standard (in north America anyway) 2- or 3-slot household AC receptacle (wall outlet or even wall socket).

A red LED on the charger should now come on.
When this light turns green, the charge cycle is complete; you should now unplug the charger from AC power and remove the 18650 cell.

This is a directly-injected laser (which by their very nature are more rugged than DPSS lasers!), 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 deep red (671nm), yellow (593.5nm), green (532nm), and light 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 deep red, 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.

***EXTREMELY IMPORTANT!!!***
This laser has a fair amount of {vulgar slang term for male nads} to it (measured at 125mW), so you ***DEFINITELY*** do not want to shine it into your eyes, other people's eyes, pets' eyes, for that matter, the eyes of any person or animal you encounter.

Eye damage can occur faster than the blink reflex can protect them, regardless of what species' eyes you irradiate with this laser. So just don't do it.

And para los motivos de Cristo (and for heaven sakes and for Pete sakes and for your sakes too) do not shine this laser at any vehicle, whether ground-based like a motorcycle, car, or truck, or air-based like a helicopter, airplane, or jet. And if you shoot it at a person in the dark and he turns out to be a police officer, he may think he's being targeted, unholster (whip out) his gun, and hose you down with it.

This laser feels wonderful to hold and use.

Power output measures 125mW.

This measurement was made on a LaserBee 2.5W USB Laser Power Meter w/Thermopile.

Beam terminus photograph of this unique (well, "not-so-unique" now) laser on the target at 12".
Beam image bloomed ***SIGNIFICANTLY***.

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.

Beam terminus photograph on a wall at ~10'.
Again, that white & blue color does not really exist, and beam image bloomed a bit.

Spectrographic analysis of the Blu-ray laser diode in this product.
Wavelength appears to be ~410m, which is within specification for the type of laser diode used in this laser.

Spectrographic analysis of the Blu-ray laser diode in this product; but spectrometer's response narrowed to a band between 410nm and 420nm.
This shows that the wavelength is in fact 414nm.

The raw spectrometer data (tab-delimited that can be loaded into Excel) is at http://ledmuseum.candlepower.us/45/br30.txt

USB2000 Spectrometer graciously donated by P.L.

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

In leiu of a beam cross-sectional analysis, I furnish the following photograph: