Re: new Sharp 495nm diode(after testing it confirmed just 488nm)

[paul1598419]

Re: new Sharp 495nm diode

does it look something like this?

this is my 20mw violet and it sounds like its doing something similar to what youve described

edit: 100th post!! yay!

Merpie, your photo isn't showing. Check the correct code on Imgur.

 

[Emialias]

Re: new Sharp 495nm diode

Merpie, your photo isn't showing. Check the correct code on Imgur.

im sorry but i have to use the mobile app which only gives me 1 url. idk what else to do. i checked the format on my previous successful image posts and the format is identical.

 

[Astralist]

Re: new Sharp 495nm diode

im sorry but i have to use the mobile app which only gives me 1 url. idk what else to do. i checked the format on my previous successful image posts and the format is identical.

Here is the direct link for your image, but it's too large to fit in forum:

http://i.imgur.com/7qilQrA.jpg


Anyway, mine looks quite like that,

and after re-observing the phenomenon, the dim dot at the center of the beam are not coming from the diode itself
i could say that it's maybe because of simple physics i.e diffraction when laser beam passing through a circular aperture
because at the near aperture the beam are clean, but not when far from aperture.

check the sample image from wikipedia
https://en.wikipedia.org/wiki/Diffraction

 

[paul1598419]

Re: new Sharp 495nm diode

IDK, astralist. It would have to pass through a very small aperture to produce that kind of interference pattern. To be donut moding it would have to have a Gaussian profile which doesn't happen with direct diodes. Not really sure what you're talking about, but I would like to know what is causing it. I was able to see the photo that Mepie tried to post, but I have no good idea what is causing it. I'll have to check all my 405nm lasers to see if I can duplicate it. Then, maybe I can find out why.

 

[ZRaffleticket]

Re: new Sharp 495nm diode

Oh my. I never saw one get like that.

Also - lasertack says there is no dedicated 495nm. Sounds like these were development diodes, or something sharp intended to keep locked up in a vault

Edit:
No news on the PLT5-488 yet from existotem. No shipping notification. No responses to my messages... so the order is now cancelled. I'll wait and see how this '495' turns out; and see how the other lead on <$300 488's turns out before I make any other decisions...

 

[Emialias]

Re: new Sharp 495nm diode

IDK, astralist. It would have to pass through a very small aperture to produce that kind of interference pattern. To be donut moding it would have to have a Gaussian profile which doesn't happen with direct diodes. Not really sure what you're talking about, but I would like to know what is causing it. I was able to see the photo that Mepie tried to post, but I have no good idea what is causing it. I'll have to check all my 405nm lasers to see if I can duplicate it. Then, maybe I can find out why.

idk what kind of hole it would have to be passing through, because the smallest hole i can see the beam pass through on its way out the aperature is the diode window itself. nothing else is getting in the way except for the lens and even then none of the light is catching on the edges?

 

[Atomicrox]

Re: new Sharp 495nm diode

I've seen distortions like that caused by the lens, but only with the dot focused far away (5-10m).

 

[ZRaffleticket]

Re: new Sharp 495nm diode

Received word from one of my contacts that these are mislabeled sharp 488nm diodes, or pre-production/ development sharp 488nm diodes. Asked for more info, stay tuned.

 

[Dr.Laser]

Re: new Sharp 495nm diode

Received word from one of my contacts that these are mislabeled sharp 488nm diodes, or pre-production/ development sharp 488nm diodes. Asked for more info, stay tuned.

Interesting, so they got the datasheets mixed meaning a 495nm from sharp do exist somewhere.

 

[ZRaffleticket]

Re: new Sharp 495nm diode

Potentially, yes. Or they just whipped up a datasheet on the first one they saw, deemed the batch a failure, and got rid of them.

But the 495 most certainly should not exist according to what I'm getting.

 

[paul1598419]

Re: new Sharp 495nm diode

It's funny how rumors tend to circulate when there is a previously unknown diode floating around. I don't know that I'd pay much attention to all these speculations as they are most likely just people's guesses.

 

[Emialias]

Re: new Sharp 495nm diode

so it was a rumor? or do they exist somewhere and the seller got things mixed up? i got hype for a little bit there

 

[Singlemode Laser]

Re: new Sharp 495nm diode

so it was a rumor? or do they exist somewhere and the seller got things mixed up? i got hype for a little bit there

I hope they exist. It is the same technilogy like the 450nm and 520nm diodes. So making the 495nm diodes is only (that could be a long process though) optimizing the manifucaturing process. Osram has a 499nm batch listed under their "special selection", so its definitly doable.

 

[ZRaffleticket]

Re: new Sharp 495nm diode

All I know is that I have info on sharp 488s coming out, and radio silence for 495nm. These diodes came out of nowhere, unlike the 450s and 520s we see everywhere.

 

[ZRaffleticket]

Re: new Sharp 495nm diode

Warranted double post. This diode is noticeably greener than 488.. but very close to it in color. This is a keeper.

 

[paul1598419]

Re: new Sharp 495nm diode

Damn! I wonder where it measures out to? I need to get my hands on one of these diodes. I have a 488nm single line argon to compare it with, but the wavelength is going to say much more.