Custom dichro for mixing 635 nm with 660 nm

Hey folks...

There's been a lot of talk about how nice it would be to have both 658 nm red and 635 nm red in the same projector. I looked into this about a year ago, and it's expensive, but it can be done. At the time, we were looking at around $165 a piece for a 1 inch diameter dichro that would do the job, but we'd have to order 10 of them at a minimum.

Several people mentioned their renewed interest in this idea at SELEM 2008, and it's popped up a few times in other threads recently as well, so I thought I'd see just how much interest is out there for this...

First, a few details: We'd have to order this as a custom dichro from Semrock. It will take about 2 weeks from the time we place the order. Also, we're paying by the square inch. So there's no difference in price between a round 1 inch dichro and a square one. (But the round one will fit in a dichro mount easier.)

Efficiency will be around 98% for the reflected beam, and 96% for the transmitted beam. (Note: those aren't guarenteed figures, but the woman I spoke to said that the performance should be close to that.) These are based on 45 degree angle-of incidence for the reflected beam.

So, assuming that the cost of the dichro is around $165 per unit for a 1 inch diameter piece, how many people would be interested in buying one? Also, does everyone want a round dichro, or would a square peice be better? (It makes no difference on the cost.)

I'm thinking that the best way would be to spec the dichro to reflect 660 and pass 635, but it might have to be made the other way. I need to check to be sure.

But before I spend another half-hour on the phone with the people at Semrock, I want to know if this is doable or not. If we don't have 10 orders at a minimum, it's not going to happen.

If you want one of these things, and would be willing to pay up to $175 for one, then reply below. If we get 10 people that are interested, I'll head up the group buy. (The first step, once we have 10 people that are willing to participate, would be to contact Semrock and get a written price quote that includes specs and delivery details.)

Adam

I'll bite, I got that much back from the SELEM raffle... :D count me in for one.

I could do one at that price -

Anybody got a cheap, powerful 635 nm diode laser they want to sell as well :D

Randy

Please can you put me down for 2 of them Adam?

Thanks for sorting this out :)

We would be interested in grabbing a couple of these 2 :)

Wow! That's more interest than I though we had. Less than 24 hours and we've got enough interest for 7 pieces (including me). Guess I need to get on the phone to Semrock this week! :D

Re: cheap 635 nm red... Dave and Adrian have pretty decent prices on their 635 CNI's. I was thinking about adding around 100 mw or so. My hope is that if you stick with a lower power 635 nm laser, the beam quality won't be so awful. (And really, 100 mw of 635nm red is going to look brighter than 400 mw of 658 nm red from a pair of Maxyz modules, so you'd effectively be doubling your red...)

Of course, my next problem would be finding a place to put the damn laser in my projector. I've got no room left!

If anyone else is interested in this, please reply below. I'll get started on the details...

Adam

put me up for 1. :)

put me down for 1

Steve

Hi Buffo -

What's the quantity required for a second price break?

Tim

Tim;

I'm not sure. I would guess probably in the high twenties or so. I know that if we can get up to a quantity of 100 pieces the cost comes down by about 50%, but that's pretty optimistic.

I called Semrock 3 times today, but the woman I wanted to speak to wasn't in. Will try again tomorrow.

Adam

I think "pretty optimistic" is quite the understatement!! :D

ill take one depending on price


**

ignore that i just read it again, expensive for me

sorry

What about 650nm? If so I would like to grab a couple as well.

Sorry Doc, 650 nm is going to be too close to the cutoff for this dichro. You'd end up loosing a lot of power (like 40% or more).

Update on the dichro... It seems that Colleen doesn't work for Semrock anymore. However, I got in touch with her replacement, and the new guy sent me this response curve for the dichro we're looking at:

http://www.photonlexicon.com/gallery...3-1/dichro.jpg


As you can see, the reflectance at 635 is really good - around 98% is reflected and only 1-2 % gets transmitted through. However, when you get to the 660 nm end, the efficiency isn't quite as good. Looks like around 93-94 % makes it through.

Still not to bad though. I asked him to give me a quote for a minimum order of 10 pieces that are 1 inch in diameter. I also had him quote me the standard size, which is a rectangular shape. We'll see what the price difference is. I should have an answer in a day or two.

Adam

shaking with an arsenal of 600mw of 660nm and 250mw of 635nm at the ready...........

Quote:

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Originally Posted by buffo

Sorry Doc, 650 nm is going to be too close to the cutoff for this dichro

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Adam, did the guy at Semrock mention if these filters can be "angle tuned" to shift those specs, as with more broadband dichro filters?

With my RGB getting ready to fire up and FINALLY pull out of the garage....NOW.....even B4 this happens.....a possibillity to add 635 !!!!! to my current Maxyz Duals......mmmmm???? But....no more room....unless....
I add the 635,,,,,ATOP the Maxyz...do a 90 reflect ...down....and put the Dichro/Holder on its side in the beam path.....only down side is the 1% loss associated with the bounce mirror !!! This layout would give Salvodor
Dali a nightmare !!
Next question......What is the MAX mw....with decent beam specs....and a reasonable price ( < 1k ) can one get in a 635 ??? and where??? and how do you modulate the beam power......just put it on another ILDA color channel I assume ???
OK...I MIGHT be interested...especially considering the eye responsivity to 635 !!!.....and it IS a great colour !!
In closing....I have another dream ( nightmare ? ).....do this same stack concept with the new 443 DI ( When and IF they get real on the price !! )...to give the blue area ahelva kick in da pants ????


PS....So VERY sorry I had last minute family commitments....and could not be at SELEM 08.....that truly sucked !!!

CDBEAM/Bob...and Terrawatt too !!

No problem Bob - family comes first! You were missed at SELEM, however.

Sorry to increase your choices for your projector like that... Especially since you're so close to being done! I was planning on adding around 150 mw of 635 to my projector (I've got the dual Maxyz setup too). Don't know how bad the beam specs are for the lower power 635 reds, but I'm hoping they'll be reasonable.

Modulation: Two choices... Use another color channel (if you have Pangolin LD-2000), or wire all your reds together on the same channel and live with whatever balance you get with it. (Might see some shift from red to orange if you do this, but the effect should be very subtle.)

P1t8ul;

I didn't ask him about angle tuning. I did tell him that we would be working with a nominal angle of incidence of 45 degrees though. I'll check on the angle tuning. (My guess is that it won't make much difference because the cut off band is so narrow to start with, but I'll ask.)

Adam

Quote:

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Originally Posted by buffo

I'll ask

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Cool, thanks :)

Ok people, more info on the dichro order. The standard rectangular shape that they normally sell the dichro in is 25mm by 36 mm. Those are more expensive, however, because they are larger. (They go for $195 + shipping.)

The 1 inch diameter round dichros are smaller, so they cost less. However, there is a "sizing fee" applied to each order. This sizing fee is the same whether you order 2 dichros or 20 dichros. It's a flat fee of $100 that gets tacked on to the order. Still, I think this is the way to go, since it's still cheaper this way, and the 1 inch round dichros will fit the vast majority of the mounts out there.

Now for the pricing: If we order 10 or more units, we can get them for $145 each. If we can get up to a minimum order of 20 units, we get a $10 discount on each piece. Note that shipping from Semrock will still apply in either case.

So here's how it breaks down: $1450 for a lot of 10 dichros, + $100 for the sizing fee, + $23.50 for shipping to me (ground), gives a total of $1573.50. Divide that back by 10, and you get a total cost per dichro of $157.35

Now add in USPS priority mail shipping to you (with delivery confirmation) for $5.50 and paypal fees ($5.02 per dichro) and you get $167.87 each. Note - if you want insurance on the package, that will add another $2.60 to the cost.

International deliveries will of course be more expensive. A good guess for international shipping will be between $15 and $25. PM me with your details and I'll get an exact quote to you. I think insurance should be mandatory for international shipments, because delivery confirmation isn't always available. EDIT: Just found out that international shipping is going to run around $30 to most destinations. You have to upgrade to either Priority or Express shipping in order to get insurance on an international shipment, and that increases the cost. Thus it will cost $193 to ship one dichro internationally, or $355 to ship two of them internationally.

So, our price ended up right about where we figured it would be. $167.87 for 1 dichro delivered domestically. $170.47 if you want it insured. (Note: If you want two dichros, the shipping amount will be the same, so double the price and then subtract out the extra $5.50 for shipping on the second one. Insurance rates will still apply though.)

If you guys want to do this, they (Semrock) need a 1 week lead time to get the dichros sized for us. After that, they'll be sent to me, and I'll have to re-package them and ship them back out to you. Also, I should point out that I'll be on vacation (and out of Internet range) starting on September 6th, and lasting until September 14th.

It would be great to get this wrapped up before I leave for vacation, but maybe it would be better to wait until I'm back.?. You guys think it over and let me know. But I'm ready to pull the trigger on this group buy if you are.

If we want to do this before I leave, I would need to close the group buy on Friday, September 5th, so I could get the payment sent to Semrock before I left. Otherwise, I'd need to leave it open until at least the 16th or so. You guys decide what you want to do.

If everyone is ready to do this, then send your paypal payment to adburns@sc.rr.com. I'm a verified business member, so you can use your credit card if you want. (I get hit with paypal fees no matter how you pay.)

And again, if you need international shipping, send me a PM with your delivery info and I'll get an exact shipping quote for you before you submit your paypal payment.

Adam

PS: I'm still waiting for an answer about angle-tuning with regard to this specific dichro. I *believe* they will be tunable, but I don't know for sure yet.

I have a credit card at the ready... >:)

Whatever works for the group works for me - probably won't really put it to use until early '09 (but then, I also wasn't planning on "Getting Pango'd" so early either!! :rolleyes:

Ready here....one unit confirmed for me please. Maybe set up a page for confirmation or just a talley of those who are getting one or more of these. Just a thought......

Ok - the majority wins! (Thanks for all the PM's guys!)

Go ahead and send your paypal payments now. I'll keep tally of who has sent payment and will update the total here in this thread. If everyone gets their payments in by next week Friday, I'll fire the order off to Semrock before I leave for my vacation.

BTW, it turns out that international shipping is pretty much the same no matter where you send it. The UK, Sweden, Australia, they all end up costing about ~ $30 when you include insurance for Priority International service. (And, of course, you can't get insurance unless you go Priority or Express.) So figure an extra $30 to ship them internationally. (Weight isn't a factor, so the shipping cost is basically the same for 1 or 2 dichros. The only difference is insurance, and it's trivial.)

Adam

PayPal headed your way -

Thanks for taking the lead on this!

Randy

Which way round do the reds have to go?

Pass 660 and reflect 635 or visa versa?

When will these things come down in price?

Update on group buy status:

P1t8ull was first out of the gate with a confirmed payment for 2 dichros
Stuka is second with a confirmed payment for 1 dichro
Buffo is confirmed for 1 dichro

6 more slots to fill...

Quote:

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Originally Posted by laserLips

Which way round do the reds have to go?
Pass 660 and reflect 635 or visa versa?

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Hi Graham! Been a while...

You had it correct the first time. These dichros will pass 660 nm red and reflect 635 nm red.

Quote:

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When will these things come down in price?

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Not anytime soon, I'm afraid. There isn't much demand for these dichros. I had to contact nearly a dozen manufacturers before I found Semrock. Most companies were unwilling to even discuss a custom dichro run, and none of them had anything that was even close to what we needed. Fortunately for us, Semrock had already developed a coating with these properties for another client. But they're still rather expensive. (Semrock in general is known for high quality optics, but they come with a high price tag too!)

Adam

Ok Adam thanks.

Yeah, long time no lase.

It's a shame they are so pricey, I have my maxyz's which I dont really want to part with and I'd like to see what wonderfull reds/oranges/yellows could be accomplished using 660 and 635.

this would of course demand that I upgrade my green from 100mw which in turn means more money, so it's probably a good idea that I can't get one of these.

Look forward to seeing some pics from you guys.

Graham

Understand your situation, Graham. We'll keep you posted of our progress.

Update: Just got the information from Semrock concerning the angle tuning ability for these dichros.. Straight from the horses mouth:

Quote:

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The specifications for these dichroics are for 45 degrees of angle of incidence. However, when the angle of incidence changes, then the spectra of the dichroic also shift and this can be used to adjust the cut off frequency.

The 50% transmission point of this dichroic can shift by about 55 nm (from 650 nm to about 705 nm) when the angle of incidence is changed from 45 degrees to zero. Similarly, when the angle of incidence is changed to 60 degrees (from 45 degrees) the 50% transmission point can shift to about 617 nm (from the 650nm, design specification). It should be noted that beyond the design specification (45 +/- 1.5 degrees) the reflection and transmission can be compromised.

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So, Dr. Laser, if you're still interested in working with 650 nm red, this might be an option for you. However, you'll probably loose some efficiency on the 635 nm end. Your call as to whether it's worth it to buy one to experiment with or not...

Adam

http://www.candlepowerforums.com/vb/...ies/paypal.gif

Update: We now have 6 confirmed payments!

allthatwhichis - for 1
buffo - for 1
dave - for 1
p1t8ul - for 2
Stuka - for 1

4 more to go and I send the order to Semrock! (Damn, this is moving fast...)

Adam

I now need to sell the argon to start the fund for set of Maxyz... :rolleyes:

LaserNerd is looking for an argon laser... Maybe you can work a deal with him. (Yours is multi-line, right?) Send him a PM...

Adam

Update: Oh hell. Looks like we may be looking for another buyer... One of the original buyers may have to opt-out of this group buy.

Anyone else interested in a custom dichro that will allow you to mix 635 nm red with 660 nm red?

Adam

Update number 2:

We have had 3 buyers back out of the group buy. :( The total right now stands at 6 confirmed (and paid) orders with 1 order pending payment. But we need a minimum of 10 to do the group buy.

The buyers that backed out said that they might be able to complete the group buy in a couple weeks - pending the availability of funds.

I am leaving it up to the rest of the confirmed buyers to decide if it's OK to wait on this. If you don't want to wait, I can refund everyone's money now, before I leave for vacation on Saturday.

Let me know what you guys want to do. I'm OK with waiting, but I want everyone else to have the chance to express their wishes.

Adam

I'm OK with waiting for a while....

Me 2
..............................

Hey guys;

Just an update. First - I'm back! Second, we're still short three buyers. I'm waiting for payment on one buyer, and if that comes through we'll be at 8 buyers. But we need 10 to complete the order.

So come on people! Where is all that interest in the custom dichro to reflect 635 nm red and pass 660 nm red? We've been talking about it for a year now. Surely there are a few more people out there that want to try this?

Adam

Adam

Will the dichro be o.k. for 637 or 640?, some of these seem to have better beam specs than the 635's (although more expensive). I'm considering combining my Maxyz with the above.

Cheers

Jem

Hi Jem;

640 nm is actually the designed cuttoff frequency for the dichro, so yeah, it will work just fine. You can also "angle-tune" the dicrho to shift the reflection band slightly, if you wanted to play around with 643 nm, for example. (But 650 is out of the question. Too far into the transmission band.)

Look at the chart I posted above. They claim 3% reflective loss at 640 nm. With angle tuning you could probably get that down to 1% loss, and still pass 95% or better of your 660 nm red.

Adam

Let me know when you need the funds for one of these...I still want one. BTW check out the GB I have started on the 635nm diodes. I want to place the order with my vendor this friday. They are the good diodes....I have baught a few and they all are just great! All way over spec and speedy shipment to me in the tray from the manu! I am almost finished with the 350mw 635 laser. This is a realistic power level.....I expect more from two 235mw diodes combined. Still locking down the optic mystery. Getting closer though...and no prisms!

Quote:

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Originally Posted by MechEng3

Still locking down the optic mystery. Getting closer though...and no prisms!

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1st law of optical physics. If the source is sh1t the result is sh1t:D

Aber ich habe mit dem sauberen, gut gepflegte Hafer angefangen und werde schließlich gutes Bier haben. So I should get better results than I have now. My laser is now doing as well as a lot of nice lasers that are on the market now. It is torn down again for optical improvements.I have all the designs in Winlase 2.1 and GLAD laser software. Very helpfull.

Was muss dies, mit Bier zu machen?
:confused:

Gerade Anzeigen über das Bilden von Qualitätsbier. Bessere Zutaten, schmecken Sie besser. Bessere Diode, besserer Balken!
Es wird in der Nähe davon..... pix angeschlagen beendet zu werden, sobald ich es beende.

Quote:

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Originally Posted by MechEng3

Let me know when you need the funds for one of these...I still want one.

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We're ready to complete the order now, Mike. Give me a call on the phone and we'll work something out.

Quote:

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I am almost finished with the 350mw 635 laser. This is a realistic power level...

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This is exactly what we need to talk about! :D We can work out a trade of sorts I think.

Adam

Ok people - we've got the minimum of 10 orders, so I'm ready to pull the trigger on this group buy. Here's the orders as they stand:

allthatwhichis - for 1
buffo - for 1
dave - for 1
p1t8ul - for 2
Stuka - for 1
MechEng3 - for 1
Jem - for 1
Mixed Gas - for 1
Max-84 - for 1

If anyone else wants to get in on this, send your paypal payment right now to adburns@sc.rr.com. Barring any last minute requests, I'm going to submit the order on either Tuesday or Wednesday of this week.

Adam

Cool!

Now all I need is an "affordable", no-machining-required, all-parts-included 635nm laser kit :D

Quote:

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Originally Posted by Stuka

Cool!

Now all I need is an "affordable", no-machining-required, all-parts-included 635nm laser kit :D

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HeHe, me too :D

Oh, and it's got to have Fab' beam specs too!!

Jem

how are you folks getting 660nm I am looking at side pumped brewsters yag into 1319nm resonator to pump some red coated ktp for 659nm is 660nm a argon line?