Red Green Orange Yellow

Hello Everyone,

I just wanted to share a picture I took last night of my collection of colors....

Enjoy!

Awesome!

Really liking that 594nm one, such an awesome color

-Alex

Looks nice!

Tha Greenlander said:

Awesome!

Really liking that 594nm one, such an awesome color

-Alex

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Thanks. Everyone calls 594 yellow but it is really more of gold-yellow. I first saw a yellow Laser Chorus laser in 1989 at a club I worked in. I have been hooked on lasers ever since.

SilverFire said:

Looks nice!

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Thanks. I have been putting the collection together for a long time.

i say this in the kindest possible way but I hate you


Seriously though amazing collection. I'm still after the elusive 612nm to complete my HeNe rainbow. Someday I'll get around to shooting an updated pic of my RGY HeNe tubes since I finally have a high powered red tube.

The oranges are getting harder to find. Oddly enough it is getting a lot easier to find greens, I think because of the influx of direct greens pushing the hene's into surplus.

Sigurthr said:

The oranges are getting harder to find. Oddly enough it is getting a lot easier to find greens, I think because of the influx of direct greens pushing the hene's into surplus.

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greens have never been hard to find... and they're relatively cheap for their size. its just that the market for yellow and orange is very little. mostly just biomedical. so naturally the price is higher when you only produce a tiny fraction and its being sold for science rather than entertainment... IR ones its the same story. and they also therefore tend to live out their lives, rather than get used for 100 hours and then discarded.

Sigurthr said:

The oranges are getting harder to find. Oddly enough it is getting a lot easier to find greens, I think because of the influx of direct greens pushing the hene's into surplus.

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You can get them on ebay all the time, just need to know what to look for. PM me if you want the exact thing they are in. But, they are soft seal (or so bloom tells me), so there's a chance they need to be run for quite a while to get up to health, or wont work at all.

I don't count gas analyzers and stuff. We're talking actual laser heads crazy...but yes they do pop up in old particle counters and things sometimes. but they are designed for red, and are not always other color tubes. Just depends on what the original purpose of the device was.

All I meant was you can get them if you want, not strictly the heads. Maybe Bloom told me wrong, or maybe i misunderstood- or heck for that matter, maybe he just got lucky and assumed- but I thought the particle counters had orange tubes in them. Where have you seen they are designed for red? Not trying to argue with you, I'd just like to get it straight.

Sorry I guess I wasn't clear either. you're not wrong, it just depends on the model of the counter. it depends on what it is supposed to be analyzing. I've seen them be anything from red only to 11 lines or some wild something like that. (most of them IR lines) Orange isn't exactly a useful WL in most scenarios. therefore it is made in far lesser quantities. the mirrors are also far harder to make, as it's caught between a rock and a hard place. as they're closely related to the yellow mirrors, and the red has to be quenched heavily to get it to work right, so usually higher power oranges have other lines contaminating them, and lower power ones tend to be competing with red. almost every orange i've seen has a bug somewhere.

They're just inherently a pain, so a lot of places have discontinued them, or only make them in very small quantities. even REO is quite stringent with how many 612s they make, vs their error count.

Interesting. I assume you mean the REO equipment pulls and not stand-alone heads. I'm completely strapped of laser funds for a while but I'll have to try and remember to PM ya about specifics.

ultimatekaiser said:

Sorry I guess I wasn't clear either. you're not wrong, it just depends on the model of the counter. it depends on what it is supposed to be analyzing. I've seen them be anything from red only to 11 lines or some wild something like that. (most of them IR lines) Orange isn't exactly a useful WL in most scenarios. therefore it is made in far lesser quantities. the mirrors are also far harder to make, as it's caught between a rock and a hard place. as they're closely related to the yellow mirrors, and the red has to be quenched heavily to get it to work right, so usually higher power oranges have other lines contaminating them, and lower power ones tend to be competing with red. almost every orange i've seen has a bug somewhere.

They're just inherently a pain, so a lot of places have discontinued them, or only make them in very small quantities. even REO is quite stringent with how many 612s they make, vs their error count.

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If you happen to find out said model, do let me know. Ive been able to find absolutely nothing about them.

Some clarification on the REO/PMS tube/heads.

What you will usually find on eBay includes the whole kit 'n kaboodle. The large system that is displayed includes not only the tube, but also the additional external cavity that makes it tick (more on that later) and the accompanying electronics.

The purpose of the system is to ensure cleanliness in a clean room environment, by monitoring the particles (i.e. dust) in the air. In parts per million, to keep up on, and regulate the room. There are certain guidelines, and brackets to various "clean ratings". Not very unlike the way lasers are rated.

So. In detail of what the laser itself consists of, parts, external cavity, how it works, etc.

Inside, once you remove the head, you will see a generic metal cylinder very characteristic of REO's tubes. The HR end of this tube will, however, be hidden in some boxy "sciency" looking contraption. On mine, it's just a black box. Most look similar, but like much of REO, they're all special snowflakes, expect differences.

Inside this box is where the "magic" happens.

These lasers use 3 mirrors. Two standard mirrors to make 632.8nm single line laser. Very hot mind you, there's a ton of light here, relative to size. Upwards of 10-15mW+, wish I could meter mine to be certain.

They then add a third mirror that is broadband HR, this is what adds the other lines to the output. The output is useless come consumer end. That side of the laser serves no purpose to really anyone using the system, aside from perhaps output monitoring.

Inside that box, between the tube's HR, and the external HR, is a clean-room environment. With a massive lens, and very large photodiode (or similar electronic).

This box is sealed with 4 screws, and a rubberized and oiled disk underneath the square lid. It is sealed to be maintained. It is lastly vacuumed out, and sealed up to remain pure and clean. Then comes a polarizor, and HR. When aligned, internally you will likely have 50-75W+ of circulating power. They are using 2 super polished, super reflective, broadband HR's. That's a LOT of light to contain.

They use this light to check the particles in the air. A sample of the air is pumped into this chamber.

I have two theories on what happens next.

Firstly, I think, is the most likely.

They use the photodiode to measure illuminated particles in the sample. Counting them, thus the name. Since there's so much light, it will illuminate the particles very well.

Of course the photodiode will be continuously sending a signal due to the cavity's brightness, in this case, they'd measure the peaks. Though in theory the particles will all be illuminated simultaneously. So perhaps they measure the photon scattering onto the photodiode. This is a two part theory, I am 85% certain it's one of the above theories.

The second, less likely scenario, is a bit similar. The photodiode in this case is being used to measure a decrease in cavity intensity due to particles in the way. Though I don't see this being the real use, as pending particle size, position, and rotation, power can vary from 0 to max.

So that's their use, that's why they are generally so heavily multiline. Every mirror in these beasts is broadband, and very equally reflective on all of them. No significant troughs in the reflectivity allows this system to work.

There's also a wide bore on these, and they're INCREDIBLY multimode. Adding more reason to all the additional light. When mine's warmed up, the light is so multimode, that at quick glance, it looks TEM00. However, upon closer inspection, it's actually a HEXAGON composed of many, MANY spots. During warmup it resembles and Rorschach painting. Just spots on spots quickly moving, morphing, and "dancing" around the output spot. Going from TEM01 to TEM22, to 03, 12, 28, etc, etc. It's all over the place.

These are beautiful systems. What I need to heavily stress, however, before you get carried away. Before you want to see what makes these things tick.

!!!!!DO NOT UNDER ANY CIRCUMSTANCES OPEN THE BOX UNLESS YOU CANNOT ALIGN IT ANY OTHER WAY AND YOU'VE MESSAGES SAM/STEVE/ME AND THEY/WE'VE TROUBLESHOOTED IT FIRST!!!!!

LEARN from my mistake. Sam told me long ago not to open these as I'd likely be faced with something I did not understand, and possibly dirty the optics involved. I agreed to let her be. A couple months before SELEM, I finally grew the cojones to go against this advice. I learned that they were sealed systems, no b-windows, the box wasn't holding anything in place, should be fine.

NOPE.

Once you break that seal, you've done a couple things.

A. RUINED the clean environment the tube was sealed in. It's gone from a clean air environment. Or at least close to it. There may have been a little leakage, but nothing like the average residential air quality. By breaking that seal, you are sucking in contaminants, adding particles to the cavity, and mirrors, that will scatter and deflect the very precious particles you need for this system to work. Getting a regular 612 or 604nm laser to work, that is designated for such, already requires voodoo magic and 10th planetary alignment. A single spec of dust can ruin that without a doubt.

B. The force of breaking that seal likely jostled the alignment. Not much, but a couple fractions of a second in one direction, combined with dust, it's toast. Much of the damage will be dealt in the form of dust. However, even if you get it cleaned up, realignment will be more challenging that you understand.

So please. Do not get brave. If you've tried everything, and you have money, time, and a few handfuls of your own hair to spare, talk to one of the above three. Hell, even Kaiser can help. Him and I have put many hours of discussion into these. I even took it apart on skype with him after I learned how to fix/realign them from Steve at SELEM. So I'm sure he can help you out just fine.

Just realize that there's a likely chance that you could do more damage than good. So consider it a dead tube before you even attempt. Set your expectations low and hope to be surprised.

A bit grim, but my 1 line PMS/REO tube on the counter can attest to everything I've said. Trust me. It's not worth it.

Enjoy it for what it is, and it'll be everything you want it to be and more

bloompyle said:

/such info/

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Wow, very good to know. i wondered what that thing on the back of yours was. Not trying to sound like a broken record, but do you remember the model number for the particle counter yours came out of? Also, in your external cavity video (if its even still up) that you did quite a while ago, wasn't that the tube from the particle counter?

crazyspaz said:

Wow, very good to know. i wondered what that thing on the back of yours was. Not trying to sound like a broken record, but do you remember the model number for the particle counter yours came out of? Also, in your external cavity video (if its even still up) that you did quite a while ago, wasn't that the tube from the particle counter?

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1. Mine came without a casing. I was a lucky one that found just the HeNe itself on ebay. Bought it, and it went to Sam for revival.

2. No, I haven't done any external work with this one. That was all done with the REO LHOR-0150. The 4 line orange.

The REO/PMS by itself, nothing external (that's not already external) does all the lines. No extra work needed.