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