Custom wavelength adjustable 462-470nm 2.3w NDB7675 build 2.7a blackbuck M8

[paul1598419]

Actually, the wavelength has nothing to do with how bright the laser is. It has to do with the tint of the color, which at 462nm to 470nm is difficult if not impossible to determine with one's eyes. It can be done with a diffraction grating. One that is 1000 lines/mm could be set up to measure the wavelength to within a nm or two if it were carefully set up, and the math involved can be accomplished with any calculator with trig functions.

 

[badboybilly]

Someone in sydney have a spectrometer, would love to prove my statement!

 

[RB astro]

Someone in sydney have a spectrometer, would love to check the (EXACT) shift!

I wish I had one but I don't Billy.
Would have been cool to see what the shift is.

RB

 

[Atomicrox]

I'd rep you but the forum won't let me.

This is really cool, I've wanted to build something very similar for a long time but never found a proper pot-controlled driver (I already have the same diode here waiting). Mine wouldn't have a fancy host, though, just a box

If you don't mind I have a few questions about the driver:
-Is there are danger/reason why you don't turn the pot with the laser on?
-When set at 2.7A can it go down all the way to the lasing threshold with the external pot? I'm asking this because it the driver's ebay page says minimum current is 1.1A and that is well above threshold, I'd like to be able to modulate the laser down to ~100mW for indoors use.

 

[badboybilly]

Hi bro
More builders should try this it's crazy how much the tint-wavelength changes with the external ujustment, I turn the external pot to were I want all the time with the laser on without any issues and it will dim the diode to off if that is the setting you want, you should be able to set it to 100mw just fine with a LPM, I could check to see the minimum lasing output if you like!

I'll do another video when I get home, in the first one I only have one hand free other on my iPhone so I couldn't keep the momentary pressed while I changed the current!

Here u go buddy I'd be ordering a driver before there all gone!

https://youtu.be/GbwFSMTl8ck

https://youtu.be/H5sy8lERfk0

 

[Atomicrox]

Fantastic, I'm eager to see the new video!

I'd really appreciate if you could check the minimum lasing output. I might buy one of these drivers depending on your results.

 

[badboybilly]

So I've added some vids ubove,
i was able to set it to as low as 10mw,
I hope this helps Atomicrox!

 

[badboybilly]

How does this wavelength adjustment work?

The only way i can think of doing that is to control the diode temperature, but that typically has a change rate of something like 0.2nm/K, so to get 8 nm of adjustment range you'd need a temperature change of something like 40 kelvin/celcius.

From the photos it looks like the diode is very well thermally connected to the host directly with no TEC/TEH system in between.

Mechanical build is amazing though

Have you read any of RHD,s spectroing on these diodes budy
This thread here proves it possible to shift wavelength by 8nm! Just by adjusting current!

http://laserpointerforums.com/f40/spectro-ing-new-nichia-1-4w-462nm-470nm-ndb7675-89422.html

Also here's Cyparagons spectro on one!

 

[Atomicrox]

So I've added some vids ubove,
i was able to set it to as low as 10mw,
I hope this helps Atomicrox!

Thanks for the videos! This is certainly one the most wonderful lasers around here.

 

[Pman]

I can't believe I missed this build. Wonderful and yes you absolutely can see the differences with adjustment. Anyone can do it with a variable DC power supply to see for themselves. There are a few diodes that really stand out with current adjustments and I've mentioned and tried to show it over and over so others will really put some thought into how hard they want to push their diodes. My favorite is the 07 although it is unfortunately more expensive than most diodes. When you buy a diode like this its like buying a bunch of diodes in a general range and you get to choose the color you like the best. Its also why i prefer an adjustable driver as the diodes themselves may differ in wavelength. We all want new wavelengths but there is a way to get some really interesting shades with what we have right now so why not take advantage of them.
This is a most excellent build and I'm thoroughly impressed. I sure wish I could do what some of you can. Being a machinist and in this hobby is like a perfect marriage.
This reminds me that I have all these gratings now and haven't gotten around to using them yet. I've just been super busy with others lasers and life to get around to trying them out. I first need to see how a couple of known wavelengths come out before trying others.

Anyways, I HIGHLY suggest you buy another 07 with an adjustable SXD V-3 set to max which should be somewhere between 5.3-5.5A and be amazed at how different the color is. Unless the diode is wavelength is way low to start I would expect it to have some green tint and be night and day different from your other one.

 

[Sceeker]

What a really nice build !
Bravo !

 

[badboybilly]

Thanks Pman!
I might just do that but with adjustable blackbuck M8 at 6+amps and just watch that wavelength shift before my eyes, on the go, I might add a 6x pair and correct it also, now that would be a cool laser, so much I want to do and so little time, at the moment this adjustable build is my favourite but not for long, glad you all like it!

What a really nice build !
Bravo !

Thanks bro!