1W 520nm Nichia Laser Diode TEST

[dave]

no way on earth you are going to get me to even try de-can an $800.00 diode

With you on that one... Never needed to in the past, so I cant see myself needing to in the future.. I have found the smear is a combination of diode not being centred in relation to the lens, and just plain bad lens choice,,,

[TechJunkie]

The smear exists on both the 445 and 520 in the pics above so I'm assuming it's something consistent between the 2.

Right, its the G2 lens. The lens produces a square artifact. Here is a picture of the G1 spot. Its the same as the G2.

With you on that one... Never needed to in the past, so I cant see myself needing to in the future.. I have found the smear is a combination of diode not being centred in relation to the lens, and just plain bad lens choice,,,

The diode is centered, its just letting through more light than the standard lenses, so you are seeing more of the raw diode output, or reflections that were not easily perceived though the 3 element lenses. Its not a bad lens, it gives an increase of almost 30% power. For the money you cant go wrong. I doubt you'd see the artifact in a show. Unless you were looking for it that is.

I'm sure DTR has better info than me. Give him some time to pop in.

[TechJunkie]

no way on earth you are going to get me to even try de-can an $800.00 diode

You would if the window came lose, and was knocking around inside your $800 diode.

Its really easy. you'll laugh when you see how DTR does it.

[TechJunkie]

Sorry to triple post, but I just found a picture of a crystal beginning to lase that my friend took.

Look at the very front profile of the crystal. Then look at the artifact of the lens again. Notice anything???

[mixedgas]

I've had several of the Nichia blue diodes become lumia generators. Simply by cleaning the window with methanol on a swab. Often they have very poor sealing on the widows. The Methanol made it to the other face of the window with whatever residual sealing agent. Instant fog.

I can see de-canning, but I'd have to put them in a indium or Low Outgassing Epoxy sealed box.

Steve

[DTR]

Keep in mind in this picture the box is extremely exaggerated on purpose to show they have the same artifacts. When the diode is putting out full power the box is so faint in comparison to the dot. This is present with the M140, 9mm 445's and these new 520nm diodes when using a G-2. Every lens has some artifacts with multimode diodes.

[swamidog]

a little bit of spatial filtering will take care of it.

Keep in mind in this picture the box is extremely exaggerated on purpose to show they have the same artifacts. When the diode is putting out full power the box is so faint in comparison to the dot. This is present with the M140, 9mm 445's and these new 520nm diodes when using a G-2. Every lens has some artifacts with multimode diodes.

[m0f]

I find with the blues at least, it disappears completely once it's being scanned, so never found it worth the effort of spatial filtering. Green might be a different story due to the difference in perceived brightness.

[LightningStalker]

One thing I've noticed with the G2 is a spiral pattern apparently emerging from whatever manufacturing technique was used. It is only apparent on a large defocused spot, though. It could have been ground out, but probably at the risk of altering the perfect aspheric shape. I have not yet compared it to other aspherics so it is possibly a common trait.

[lasertack]

Hi guys,

There seem to be some interest in 520nm coated mirror prisms, so I started a GB for http://www.photonlexicon.com/forums/...136#post283136