Dye Laser Comes to Life!

[Seoul_lasers]

yes, I was wondering about the Air flash lamp. Other versions of dye lasers use a TEA Nitrogen laser as a pump source, same idea... more or less. How was the price for the Rhodamine 6G and other dyes you used?

 

[Anthony P]

I don't have the invoice anymore. 1 gram of granulated laser dye makes a whole bunch of solution. Keep in mind the price of an analytical balance.

https://exciton.luxottica.com/checkout/cart/

 

[Eddie H]

For dye I found that a stabilo pink highlighter was more or less R6G, it was the simplest laser ever that I had it working as. I pumped it with a TEA laser made from a brass carpet door strip cut in half, foil and a binder divider as the dialectric, foil and folder polypockets rolled up for leyden jars and fed by an acrylic sheet rubbed with a cotton cloth by a car wiper assembly. It fired once every 4 or 5 seconds and had miles of scope for improvement but in the dark the weird yellow/orange colour flashes looked amazing. Though I only saw them on camera I was impressed they came out that colour as usually yellows turn green on camera for some reason. I'm keen to build a similar but scaled up one next powered by wimshurst exercise bike, but I'm also in the middle of putting together a magnetron CO2 slabby so unless I get frustrated and need a break the big-T probably won't be til end of August. I do have some nice pvc pipe, a pair of 4' alu 2" angle for electrodes and a few bottles of welding nitrogen... hmmm...

 

[Anthony P]

For dye I found that a stabilo pink highlighter was more or less R6G, it was the simplest laser ever that I had it working as. I pumped it with a TEA laser made from a brass carpet door strip cut in half, foil and a binder divider as the dialectric, foil and folder polypockets rolled up for leyden jars and fed by an acrylic sheet rubbed with a cotton cloth by a car wiper assembly. It fired once every 4 or 5 seconds and had miles of scope for improvement but in the dark the weird yellow/orange colour flashes looked amazing. Though I only saw them on camera I was impressed they came out that colour as usually yellows turn green on camera for some reason. I'm keen to build a similar but scaled up one next powered by wimshurst exercise bike, but I'm also in the middle of putting together a magnetron CO2 slabby so unless I get frustrated and need a break the big-T probably won't be til end of August. I do have some nice pvc pipe, a pair of 4' alu 2" angle for electrodes and a few bottles of welding nitrogen... hmmm...

If this link works, here is my N2 Dye Laser: https://laserpointerforums.com/threads/n2-pumped-dye-laser.105001/

As for the current flashlamp dye laser, the work progresses. I believe I have resolved the metering issues with some help from Cyp. I am almost done with the Frankenstein relay that will disconnect the meter during firing. Also, I abandoned the 4 stage multiplier circuit and went straight to a 15KV transformer with variac control and HV rectifier.

The end of this project is drawing near. Sometimes I think that the worst thing you can do with a project of this nature is finish it.

 

[safetyman]

I did the first test fire of the dye laser today. To my surprise, it worked the first time. All I could think was," Wow! That's a lot of yellow."

The cell itself is 4mmID x 110mm long. The electrode spacing on the lamp is 114mm. 1uF cap charged to 15KV. It even worked with the OC removed. With the OC in place the spot on target is cleaner and somewhat more intense. Dye is Rhodamine 590 chloide in 99.9 ethanol ( makes me wish I had not quit drinking...LOL). The beam is somewhat divergent as expected.

Moving forward, I need to figure out how to photograph output to get you guys some good pictures. Also, I will experiment with collimating lenses to tame divergence. There is more to do... but at least it works.

Merry Christmas

https://imgur.com/5jF06XM

Indeed, pure solvents are not necessary. I have read of people successfully using vodka or rubbing alcohol. Use of pure solvents just eliminates a variable... one less thing to worry about.
As far as CNC, the most sophisticated tools I own are a vise and drill press. The trick is that anything that requires precise alignment needs to be designed to be adjustable.

Nice build! Your post on Dye Lasers brought back memories to 1980. Back then I started gathering parts and pieces from North Country Scientific in NH, a successor of Henry Prescott the original owner). The phone number was disconnected. Unfortunately nearly 40 years of being stuffed in a parts drawer took it's toll on the glass parts. I would have to believe North Country is long gone. I still have the cut sheets with part numbers and pricing, along with a copy of "Light and it's Uses". I have most of the small electronic components, the dye cell, flashlamp (glass damaged), missing 1 window, etc.. home made mirror mountings intact, mirrors tarnished etc. Any idea if this company is still around by another name?

Thanks,
Safetyman

 

[Anthony P]

North Country has been gone for around 20 years. The quartz parts can be made by TGP in Ohio. https://technicalglass.com/about/
Windows and mirrors are available from Edmund Optics or Thor Labs. https://www.thorlabs.com/navigation.cfm?guide_id=2264

It is important to note that the tubing parts must be quartz, not glass. Eagle Laboratory Glass can also make custom glass parts, and quartz on special request.

I wasted a lot of time on a voltage multiplier circuit to charge the cap. Now I am using a 15kv 30mA NST rectified which has proven to be rugged and reliable. If you are going to attempt this project, start shopping for your capacitor now. It was very difficult to find something suitable.

Last note, Light and its Uses suggests $100.00 project... Not even close. Assuming you already have some vacuum and high voltage equipment, plan on $1000.00 minimum to get started.

Hope this helps.

EDIT:
North Country's mirror were very old soft coated. The coating were actually water soluble. Modern dielectrics are much much better.

 

[safetyman]

North Country has been gone for around 20 years. The quartz parts can be made by TGP in Ohio. https://technicalglass.com/about/
Windows and mirrors are available from Edmund Optics or Thor Labs. https://www.thorlabs.com/navigation.cfm?guide_id=2264

It is important to note that the tubing parts must be quartz, not glass. Eagle Laboratory Glass can also make custom glass parts, and quartz on special request.

I wasted a lot of time on a voltage multiplier circuit to charge the cap. Now I am using a 15kv 30mA NST rectified which has proven to be rugged and reliable. If you are going to attempt this project, start shopping for your capacitor now. It was very difficult to find something suitable.

Last note, Light and its Uses suggests $100.00 project... Not even close. Assuming you already have some vacuum and high voltage equipment, plan on $1000.00 minimum to get started.

Hope this helps.

EDIT:
North Country's mirror were very old soft coated. The coating were actually water soluble. Modern dielectrics are much much better.

Anthony P: Thank you very much for providing links to current suppliers! I am curious....I wonder if anyone ever talked to the last owner of North Country and what was the outcome for the remaining parts? My mirrors look exactly like your description. I kept them dry and clean in a old contact lens case. Did not help much. $1K is alot but this can be an extended project for me. I will be watching your project .
Thanks!

 

[Anthony P]

Anthony P: Thank you very much for providing links to current suppliers! I am curious....I wonder if anyone ever talked to the last owner of North Country and what was the outcome for the remaining parts? My mirrors look exactly like your description. I kept them dry and clean in a old contact lens case. Did not help much. $1K is alot but this can be an extended project for me. I will be watching your project .
Thanks!

I did talk to North Country all those years ago. After Mr. Prescott passed away, his family was was selling off any remaining parts and shutting down. When I had my lamp and dye cell made, I had spares made. I might be willing to part with a set if you like the specs I have.

As for mirrors, I am using an Edmund Optics broad band dielectric 400-700nM 99% for HR and 70/30 beam splitter from Thor Labs for OC.
I originally use a set from a yellow HeNe... the current set seems better.
With the lock down orders for covid, I have had extra time and will be wrapping up the project soon. I need to get photos and some video clips made. I think a short gif will be the best way to photograph the beam shots. I will also try some coumarin 450.

 

[Anthony P]

Just a small update...

https://imgur.com/g5Z8D0b

 

[Jim H]

When you bought your dye, did you have it sent to a business address? I had a hell of a time finding someone who would sell it and ship it to my house.

 

[RedCowboy]

Need to see more pics.

 

[Anthony P]

Still fine tuning, and will also try coumarin 450. Then I promise lots of pics. I have a theory that reducing the dye concentration will reduce divergence. I will also try some collimating optics.

I do not remember if I had the dye shipped to my home or business. It came from Exciton. Also, check out "Right Price Chemical" for solvents.
PM me if you need a business address for shipping.

 

[icecruncher]

Wow. Thanks for sharing and the pics, post more please. I love yellow.

 

[Jim H]

Still fine tuning, and will also try coumarin 450. Then I promise lots of pics. I have a theory that reducing the dye concentration will reduce divergence. I will also try some collimating optics.

I do not remember if I had the dye shipped to my home or business. It came from Exciton. Also, check out "Right Price Chemical" for solvents.
PM me if you need a business address for shipping.

Exciton would not ship to my home. I ended up getting my dye and solvent from Chemsavers. It cost more, but it was the only place I could find that would send it to my home. I got coumarin 30. I don't think I looked at Right Price, I will have to check them out. Thanks for the tip!

 

[Alaskan]

My dye came from both Germany and Ukraine a couple of days ago, the 1 gram from Germany was 1/4 the cost of the 150 grams from Ukraine. What solvent should be used? I just want to put it in something and shoot a green 532 nm beam into it.

Rhodamine 6G powder, fluorescent dye 99% 150g | eBay

Find many great new & used options and get the best deals for Rhodamine 6G powder, fluorescent dye 99% 150g at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Rhodamine 6G (C.I. 45160) - 1 gram - Laser Dye | eBay

1 gram of Rhodamine 6G. C.I. Number: 45160.

www.ebay.com

I bought both to compare quality.

 

[Anthony P]

My dye came from both Germany and Ukraine a couple of days ago, the 1 gram from Germany was 1/4 the cost of the 150 grams from Ukraine. What solvent should be used? I just want to put it in something and shoot a green 532 nm beam into it.

Rhodamine 6G powder, fluorescent dye 99% 150g | eBay

Find many great new & used options and get the best deals for Rhodamine 6G powder, fluorescent dye 99% 150g at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Rhodamine 6G (C.I. 45160) - 1 gram - Laser Dye | eBay

1 gram of Rhodamine 6G. C.I. Number: 45160.

www.ebay.com

I bought both to compare quality.

I cannot answer your question about specific solvents, but I can share my experience. I have used both methanol and ethanol. The ethanol seems to have some advantages. Methanol is a more aggressive solvent so it tends to eat away at epoxy joints, tubing, and o-rings. Ethanol seems more reliable and consistent in producing a laser beam instead of just light (purely subjective observation). Also, ethanol is far less toxic.
If you are going for continuous or rapid fire output you may want to look into quenching agents. The simplest quencher seems to be simply bubbling pure oxygen into the dye solution for several minutes before use. This becomes critical if pump pulses exceed the order of 10's or 100's of ns.