565nm From LaserLandAustralia

[kecked]

Can you label what I’m looking at for those of us playing along at home. It looks like a diode mounted on brass pointing up to a channel in the brass. Does the crystal go in the channel?

 

[Mosc007]

ND:SFAP has been around since at least 1998 when the patent was applied for in the US.

It's very hard to get information on ND:SFAP as the publications have limited access. You need to be a member to download them.

In the patent there is an Emission graph when it's pumped with 808nm. There is a small spectral emission around 1130nm which when frequecny doubled with a KTP will give 565nm. It does not explain the 575nm though.


I have attached the Emission graph from the US Patent.

And a link to the US Patent document. ND:SFAP Patent

 

[Mosc007]

Can you label what I’m looking at for those of us playing along at home. It looks like a diode mounted on brass pointing up to a channel in the brass. Does the crystal go in the channel?

A C-Mount diode is different to a normal diode. The Output is verticle from the bar on top of it. When it's laying flat as pictured. The hole in the middle is for mounting. The beam will be pointing up towards the crystal.

 

[kecked]

Send me the links for the papers and I should be able to get them as I work for a university.

 

[Dr.Laser]

Here is a close up picture of the crystal, it seems that this crystal does all the work as the rest of the setup is just lenses.

 

[Mosc007]

Here is a close up picture of the crystal, it seems that this crystal does all the work as the rest of the setup is just lenses.

That does look like a KTP Crystal from a 532nm laser. Maybe it is directly pumped with 1130-1150nm IR.

What we need is someone with a spectro for IR. It's the only way we will know for sure how this works.

This thread has been about the impossable already. My money is on direct doubling a KTP Crystal with 1130-1150nm IR.

Am I correct in saying that direct doubling is still classed as DPSS ?

 

[Alaskan]

I was wondering if it might be a KTP doing something they aren't supposed to do, in theory, because the science is so pure, people don't normally do crazy stuff to see if it works, they follow down the same trodden paths, possibly missing some wierdness.

 

[Mosc007]

I was wondering if it might be a KTP doing something they aren't supposed to do, in theory, because the science is so pure, people don't normally do crazy stuff to see if it works, they follow down the same trodden paths, possibly missing some wierdness.

It's quite possible poorly manufactured crystals don't work exactly as the science says. 532nm +/- 40nm

 

[Alaskan]

Ha, maybe that's it, would explain how cheap they are.

 

[Nexgen]

I’ve contacted alibaba supplier and he said he can make 100mw 575nm or even stronger. They are going to manufacture them soon.
Let’s hope it’s real.

 

[CurtisOliver]

It is usually the coating that limits the wavelengths that a certain ktp crystal can frequency double. Not the crystal itself. Change the phase matching angle and you can then double other wavelengths.

 

[diachi]

It is usually the coating that limits the wavelengths that a certain ktp crystal can frequency double. Not the crystal itself. Change the phase matching angle and you can then double other wavelengths.

It does have a specific phase matching range which is around 990nm at the lower end, so it's no good for blue, which is why you see LBO/BBO being used there. Perfectly suitable for green/yellow applications though.

 

[CurtisOliver]

Yes that's correct. Also BiBO can be used for blues. :beer:
Was going to mention range, but it wasn't needed for the bands we're talking about.

 

[LSRFAQ]

It is a process I've seen in other mediums. I can tell that much from the pictures.

However it is limited by thermal conductivity of the host crystal microcrystal. You will NOT be overdriving this low cost one much, its designed for low power.


If I have time today I will have a friend who speaks a few different dialects do a little searching.

----------------------------- About "Guessing" from academic paper summeries on line...---------------------------
Unless it is a slam dunk fit, and you have read the whole paper, DON'T.

I have some of the SFAP papers already ... I'm not very sure at all this is SFAP, some numbers are very wrong, NOT matching by a long ways... SFAP suffers from poor heat conduction and is a $itch to make.. Guessing its ND:SFAP just because a few stated numbers /publications line up is a bad start.

Melles Griot has one of the patents on SFAP in the US, and had it for a long time. If it were that good at making a rainbow, they would have used it long ago. You sweep these crystals by pumping them with a tunable lab laser as a pump and looking for emission peaks. For a big company that is easy.

I have access to the spectrometer can check pumping out to 1200 or so, I can borrow something that goes further... If I'm really curious, I can beg for access to a tunable pump laser at a friend's lab. I'm not that curious. I just want my 575. I can also see what process is used easily enough.

Instead of trying to tweak, mod, overdrive .what is a carefully designed and made crystal, running in a reasonably reliable manor, how about just setting back and enjoying the ride?

Attached is a snippet from document. I'll leave it up for just 24 hours under educational use clause.



Steve

 

[Skittles]

I’ve contacted alibaba supplier and he said he can make 100mw 575nm or even stronger. They are going to manufacture them soon.
Let’s hope it’s real.

Tell him to make PORTABLES!!
He sent me a message about 575nm after I just checked the page, I didn't even know I had an account on Alibaba. :tinfoil:
I tried sending him a message but for some reason it doesn't work right now.

 

[paul1598419]

Well, last I looked mine is getting through customs in Los Angeles. It seems to be right on target to get to me tomorrow. Lots of great information here. :thanks: to NexGen for killing a pump diode to find it starts to foldover after 1400 mA. That certainly doesn't mean these tiny crystals can take that, but it is a starting point. And getting one to laser high enough in power to ignite a match is also useful information.

I can hardly wait for mine to get here tomorrow. It's almost like Christmas eve and I'm 5 years old again.