589nm Yellow Laser build (Beam Combining)

[hyomocha]

Greetings all...

I am attempting to build a 589nm "semi" frequency selectable (by changing the amount of 532nm light) laser. Pictures are at the link provided below.

Currently this build uses a 1W 650nm red laser and a 120mw 532nm green laser. The beams are combined using a 50/50 beamsplitter which creates two combined beams at half power. So, I believe that the pictures at the link show my combined beam at about 500-550mw of power. The beam seems "less" orange in person than in the pictures, but it is still mostly orange. If I had to guess, and I do cause I don't have a device that can measure wavelength, I would guess the beam to be around 600+nm.

My goal with this project is 589nm or as close as I can get to it. Based on professional devices that I have seen, 532nm to 650nm is about a 4 to 1 ratio. 4mw of 650nm to 1mw of 532nm. I'm not sure if that yields a beam of 589nm or not, but I think it should be close. Based on my math, equally "visible" beams of 650nm and 532nm should yield very close to the 589nm mark. I am going to buy some beam splitters at various transparencies to "tune" the laser to what I want.

Enjoy the pics that i have for now. I will post more as I complete the project. I ordered a 300mw 532nm green laser for this project and I have ordered a cylindrical lens (AR coated) and several plano convex and convex-convex lenses to play around with collimation of the beam.

My inspiration for this project are the incredible Laser Guide Star devices. They are greatly collimated and focused lasers to a point at 90km above the Earth. Doubt I will hit that distance, but I'm going to see what I can do.

More to follow!

Phase I of the Yellow Laser Project

https://plus.google.com/photos/102430102471833723587/albums/5772877002752848033?authkey=CJPBg4DUgc2VEA

Phase II of the Yellow Laser Project (Added fairly nice beam combiner)

https://plus.google.com/photos/102430102471833723587/albums/5774698877693428001?authkey=CLCX6ILn6r7STA

 

[DJNY]

Great what you did there.

Can´t wait to see more of it!

 

[hyomocha]

Thanks! I should have my "professional" beam combiner this week and hopefully my better 532nm laser as well.

 

[ZRaffleticket]

Sweet project! I've been meaning to do something like this to make an orange color.

I'm also curious about your 1W 650, what's the beam like? Is it square?

 

[Meatball]

Hey it looks great on camera! I recommend expanding your green beam with a 3x expander so that it becomes easier to align and look much more satisfying to the eye.

 

[lowell389]

That is a very nice color beam you got out of it.
I'll be checking back to see what difference the professional beam combiner makes.
Good job!

 

[Soren]

You're not really creating a 589nm laser, you're just combining 532 and 650. Regardless, it looks excellent! :beer:

 

[ZRaffleticket]

Probably a good idea to point that out. 589's would be cheap if it were that easy

 

[Things]

Yeah, you're not actually combining wavelengths, you're simply overlapping them so the eye is tricked into seeing another colour, your laser is still 532 and 650nm

 

[Meatball]

I think he is just aiming for the color balance which gives the allusion to a 589nm beam. And how else do your describe that color than by saying it is 589nm?

 

[Things]

Calling a combined red and green yellow beam 589nm is like calling a CRT an LCD, they're physically not the same thing

Most people just tend to call it a combined yellow.

 

[weeba2kv]

Come on he did a great job

 

[hyomocha]

I think he is just aiming for the color balance which gives the allusion to a 589nm beam. And how else do your describe that color than by saying it is 589nm?

Yes, Meatball, you are correct. I should have realized that posting 589nm on this board would meet with criticism, when in reality I am just combining 532 and 650.

For all those who thought I literally meant 589nm, I understand that I am combining 532nm with 650nm and that I will be "tuning" (by increasing or decreasing 532nm light) to give the appearance of 589nm yellow.

I believe I got the beam combiner in the mail today (I have a receipt for a package to pick up) and I will post pics of that today if indeed I did receive it.

So, to sum up, this is just a beam combining experiment to give the appearance, as close as possible, to 589nm yellow. I hope that clarifies to everyone what this project will achieve. Not true 589nm wavelength.

 

[hyomocha]

Hey it looks great on camera! I recommend expanding your green beam with a 3x expander so that it becomes easier to align and look much more satisfying to the eye.

I will definitely be using a beam expander to make the beams overlap better. You can even see in some of the pictures that the green beam is riding right down the middle of the red and is somewhat yellow-orange surrounded by the red.

@ZRaffleTicket
The 650nm 1W beam is pretty much a standard diode square beam. At the aperture it is approximately 5mm x 5mm. The divergence was listed as <2.5mrad. I think that is only on the X axis as the beam becomes more rectangular over distance. Other 650nm's that I have seen show the divergence as 2x5mrad, which is what I believe this one is.

I have already ordered an AR coated cylindrical lens to correct the Y axis divergence. This is my first time playing around with beam shaping so I'm a little excited to see how well it works. I'll be sure to post pics of all the optics once I get it setup.

 

[hyomocha]

Also, I want to say thanks for all the replies. This is my first time participating on a forum for lasers like this. I have been a long-time fan of Sam's Laser FAQ. Not sure if you guys remember the laser plans found in SciAm, but I started building homemade lasers in 1986 (yikes, I was pretty young then)with my first HeNe (hene tube with powersupply kit), right after building a Tesla Coil (which was a lot of fun). Since then I have been hooked on lasers.

Any other helpful hints are greatly appreciated. THANKS!

 

[Flaminpyro]

Good work your laser looks fantastic

Can't wait to see what you do with it next.