Sharp GH04955A2G/ The New 495nm diodes

[paul1598419]

This is the Sharp #GH04955A2G, 495nm laser diode. Unlike earlier versions of 480nm and 505nm, these have no micro-printing around the diode's window.

These new diodes are difficult to describe in terms of their color. To me they are right on the edge between blue and green. It is a spectacular color, IMHO.

My preliminary test results are for the first five I measured. They are at or below 495nm, but can increase in wavelength by 1nm to 2nm with heat.

I will post the wavelengths in order from lowest to highest so you can see at a glance where they tend to fall....at least, so far.

492.2nm at 75 mA
492.8nm at 75 mA
493.2nm at 100 mA
493.7nm at 100 mA
495.0nm at 75 mA

I plan on measuring the rest as soon as possible. Then I will concentrate on threshold current, efficiency, and optical power output.

So, I have measured the rest of the ten diodes I have. I also ran one up to 350 mA and left it there for ~30 seconds, until it got quite hot, to see how much these can drift with temperature. From 50 mA to 350 mA it drifted ~6nm. However, I don't see these getting anywhere near that hot or pushed at that current without proper heat sinking. I still think at 275 mA with good heat sinking they won't drift more than 2nm, especially from what I've seen with these diodes.

In the order of lowest to highest wavelength the rest are:

493.0nm
493.2nm
493.6nm
494.0nm
494.3nm

All I have left to do is press one into a copper module and put it into a handheld with a decent heat sink. Then I'll be able to take some beam shots. :wave:

For those of you that now have a diode, but don't know the pin out for it:

 

[ZRaffleticket]

Thanks Paul!

One thing I will ask is how much they shift up in wavelength at 275mA, as that's where a good bit of us will be running these.

How's the color on these? More green than blue or more blue than green, or too hard to tell?

 

[paul1598419]

Oops! It is very difficult to tell the exact color, at least to my eyes. They are right on the hairy edge of blue and green. I suspect they will look blue to some and green to others. In order to see what to expect at 275 mA, I will have to press one and heat sink it and run it for a minute. I suspect that if they are heat sinked well, they won't move more than 1nm.

 

[ZRaffleticket]

Do you have any spare modules to press into? I'll cover the cost for one. Once you get the other 5 measured I'll pick a diode if that's OK.

 

[paul1598419]

No problem. I have several modules in my stock and can press them into either copper or nickel plated brass. I was going to press mine into a copper one to test the other parameters with.

 

[steve001]

Thanks Paul!

One thing I will ask is how much they shift up in wavelength at 275mA, as that's where a good bit of us will be running these.

How's the color on these? More green than blue or more blue than green, or too hard to tell?

Since 510 nm is a green green this wavelength would tend towards blueish rather than greenish

Oops! It is very difficult to tell the exact color, at least to my eyes. They are right on the hairy edge of blue and green. I suspect they will look blue to some and green to others. In order to see what to expect at 275 mA, I will have to press one and heat sink it and run it for a minute. I suspect that if they are heat sinked well, they won't move more than 1nm.

Perhaps teal

What is the spot shape?

 

[ZRaffleticket]

The hex color I found on an online converter suggests hex #00ffcb. Now we just need someone with a calibrated monitor and one of these diodes to confirm it... but this is still probably a decent suggestion


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[bloompyle]

Very interesting results thus far. I’ll be sticking close to this one to see how this develops.

Great work so far, and great discussion.

 

[paul1598419]

These seem to be similar to the "480nm" and "505nm" diodes in spot size and shape. The color is pretty close to that Zach. But, it depends on the light around you as it sometimes looks a bit bluer than that or a teal kind of color. You'll have to see it for yourselves. I really can't describe it.

 

[waffailtrager101]

I believe the color would technically be cyan, it is about evenly between green and blue.

Doing a quick google search of cyan says the wavelength is between 490-520.

But whatever color we want to call it, those must look beautiful :drool:

 

[ZRaffleticket]

Heh, you're definitely right. These are very nice colors.

Though coming from personal opinions, just 488-500nm is cyan. In just about all conditions my 485 looks blue to me* (though enough 450nm makes it look a little cyan), and under any conditions my 502 looks green to me*

I think my camera very accurately depicts the following on my monitor:
520 vs 502 vs 488 vs 485 vs 480


Though lighting conditions drastically affect how our eyes see color. My 485 is much more blue in sunlight and much greener at midnight.

*there are just my terrible opinions - don't take them as fact!

 

[steve001]

The hex color I found on an online converter suggests hex #00ffcb. Now we just need someone with a calibrated monitor and one of these diodes to confirm it... but this is still probably a decent suggestion


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aquamarine Generally cyan.

 

[paul1598419]

Heh, you're definitely right. These are very nice colors.

Though coming from personal opinions, just 488-500nm is cyan. In just about all conditions my 485 looks blue to me* (though enough 450nm makes it look a little cyan), and under any conditions my 502 looks green to me*

I think my camera very accurately depicts the following on my monitor:
520 vs 502 vs 488 vs 485 vs 480


Though lighting conditions drastically affect how our eyes see color. My 485 is much more blue in sunlight and much greener at midnight.

*there are just my terrible opinions - don't take them as fact!

Okay. Now try to imagine a color in the middle between the 502nm and the 488nm. That is what it looks like to me. Pretty hard to describe.


I've already ordered the Nano driver. Hopefully, Jordan will get it out to me quickly so I can use it to make a build with one of these diodes.

 

[Keaton]

Can't wait to see what this looks like when it's actually put into a laser!

 

[Rivem]

Added a chat section for new diode discussion.

See this thread: Laser Discord Chat Invitation

EDIT: Vets please use the link in the vet section sticky!

Also, everybody has to confirm an email to use the discord chat for spam prevention.

 

[paul1598419]

Yeah, I'll need some new ones for these new diodes, Rivem. Will order once I know what wavelength my build will be.