Who 'd like test our dichoric

[mixedgas]

If I were installing a projector at Grand Coulee Dam, or Disney, I might invest 450$ in RGB optics. Otherwise modern dichros are much better then what I was using 15 years ago, where 65% recovery of system energy was a good day. Ion beam coating and Rugate technology has contributed much to that improvement.

Steve

[Bradfo69]

So... if I'm understanding all of this correctly... and Lord knows I don't. In laymans terms, one of type A and one of type B will be $30 plus shipping and, one is pass green reflect blue and the other is pass green/blue and reflect red. I'm in. Probably two sets. And I order through Eric? I want to see if I can improve the loss through the back of the dichros on my CT Lasers 3 watt RGB. $30 to reclaim maybe 50-80mW or more works for me.

[planters]

Doc,

These R/T specs are REALLY good. Close enough to the Semrocks I use now that the differences (if there are any) are in the noise. I was told to expect this earlier by Bridge, but I had my doubts. A few things to keep in mind with this stress discussion is that any distortion should affect reflection significantly more than transmission. The glass does not change thickness and if it bends it behaves like a zero power meniscus lens. Regarding reflection, the beams are small relative to the glass dimensions and this reduces the effect of a curved reflective surface, but it will affect co-alignment if distinct beams are converging in the far field to a single point and it will affect each diodes collimation. However, both of these effects can be compensated with existing adjustments and should be stable.

If they send me a good supply then I can drop these in the post as needed. This should cost very little.

The way I do the math is if I have a 1000mW projector that with the DAC cost $2,000 then each mW = $2 or each 1% = $20. In the most extreme scenario if the projector is limited by a week color then each 1% of just that color = $20. This applies to the diode as well as the optics.

Daniel's work is well done and it might make sense for Bridge to send him the PBS cubes as well (if both are willing) rather than ship them to me only to have me forward them to Daniel.

[bridge]

Thanks Daniel, very well test.
To All, both side are coating, different is like reflect blue pass green and red, 1 side is coating reflect blue pass green and red, the other side is only coating pass green and red, if not coating on both side, loss will much.
We can accept and strict test, we know what dichroic we are doing.
Welcome who can sell to Newport, Thorlabs, Sermorock etc company contact with us, for those products, we are really good quality with reasonable prices.
Best regards!
Bridge

[The_Doctor]

Doc,

These R/T specs are REALLY good.

I know. Thinking of what Steve said, I remember looking at various optics catalogs in the past, I don't think I saw anything this good, and their prices were high. I was just wondering what the weakest link in the chain might be because if it could be strengthened with not too great a price increase, then awesomeness keeps on increasing. I realised on waking (still working its way through my tiny brain like an earworm) that adjusting a small difference in focus is a small price to pay if needed. I imagine the main thing is to make them round. I know a lot of people like rectangular ones for mounting reasons, but some small (1cm wide) round ones would be great. I imagine that small size might have similar benefits to thicker glass. What I'm not sure is whether that small diameter would override those benefits as a result of being smaller compared to beam width.

[bridge]

We also had 15mm round dichroic in stock.

[The_Doctor]

We also had 15mm round dichroic in stock.

I'm still at the 'dabbling in diodes' stage. And short of money... But thanks, those will be what I'll buy when I'm ready.

Edit: For future reference, what kind of glue is best to use? A slightly elastic type seems wise, rigid ones might cause flex like a bimetal strip in a small mount with thin brass. Is something like low modulus silicone acceptable?

[bridge]

Daniel,
Can you using 445nm laser to test reflect red pass green and blue, from you test curve, your test is much lower than we test. thanks.
some of your test is 100%, that's look like it is machine Error bring.
Best regards!
Bridge

[danielbriggs]

some of your test is 100%, that's look like it is machine Error bring.

Despite the numerous decimal places in the spreadsheet (these are calculated from reference light/dark spectrums, then compared with what the spectrometer is seeing), the figures are good for +/- 0.5%. i.e. 100% transmission is a rounding error from >99.5%.
I hope that clears things up.

Discrete wavelength tests on the power meter will follow at the end of this week.

Cheers,
Daniel

[Junktronix]

I'm seeing the same transmission results as Danniel so I set my experiment up to measure the reflectance at 45 degrees. Initial results are in these shared Google spreadsheets (with easy to read charts)

https://docs.google.com/spreadsheet/...UE&usp=sharing
https://docs.google.com/spreadsheet/...Xc&usp=sharing

The data are a bit noisy in the deep blue. My deuterium / tungsten light source is not working and so I used a tungsten-only source which doesn't make much blue. I'll try to fix the blue enhanced light source or find a filter that flattens the output of the tungsten-only source so I can get better data in the 400-450nm range.

I used a USB2000+ spectrophotometer and a custom test jig that can do both T and R measurements. I'll post pictures of my setup later today.