Great way for smear free optic cleaning

[steve-o]

Darn! And I just bought an EO blue bounce dichro. Are you saying 90 degrees as in the beam angle and the dichro being at 45, or am I reading this wrong? Also I was laying out the new table for G->R->B-> scanners. Now I'm reading it should be G->B->R-> scanners. Is this the optimal layout for max power output? Why would it make such a difference?

[stanwax]

Steve
The layout only makes a difference if the dichros let a lot of light through. The EO blue bounce dichro when placed at 45 degrees to bounce the beam thru 90 is rubbish. The laserwave ones have a transmission of about 0.5% whereas the EO ones transmit more like 15% in my tests. You dont need hard figures though to see this - a blue laser with a LW blue bounce dichro leaves a barley detectable dot after the optic, but EO you get a beam!

In my tests with the EO optics I found that the total mw of losses across all colours add up to roughly the same which ever layout you choose - give or take. With LW optics this is not the case though I need to get solid results to back this up - which I dont have yet

Rob

[laser steve]

Darn! And I just bought an EO blue bounce dichro. Are you saying 90 degrees as in the beam angle and the dichro being at 45, or am I reading this wrong? Also I was laying out the new table for G->R->B-> scanners. Now I'm reading it should be G->B->R-> scanners. Is this the optimal layout for max power output? Why would it make such a difference?

I had 1 watt of of green 800mw red and 800mw blue. my mix was start with a red beam,then mix the green,with a reflect green dicro,then mix the blue with a reflect blue dicro. then on to galvo. but due to the power of the colours i had. this was not the wright way for me.

i changed it to. start with a green beam,then used an edmonds reflect blue to mix blue,then used an edmonds reflect red. then galvo.

Changing to edmonds dichros and changing the order in which i mixed the colours. gave me a white light that was twice as bright,as before. that was without changing any lasers,although i did add a maxi red aswell. the total cost for the double power was about £250 and a few rucks with the mrs about what time im coming to bed. lol. yes it did take a while.

the order you need to mix the colours depends on how much of a good colour balance of lasers you have in the 1st place. ie if i had that sexy 4watt at the laser meet as my red. then i would have started with a red beam.
id say and some may correct me here

you need,for a good balance about

15% green
40% blue
45% red

so if dor example you have a

400mw blue
100mw green
200mw red

u'd mix it
blue-green-red-galvo

the order changes according to your lasers powers.

[stanwax]

Why would it make such a difference?

The reason it can make such a difference is that you will always loose some light on each dichro and if that ammount of light - as in the blue bounce EO dichro - is a lot then a different layout may not yield as much loss. Everyone assumes that the blue should go last as its the most precious however if you loose 15% of it on one dichro it may be better to shoot it through a green reflect dichro (loss of 9%) and then a red reflect dichro (loss 1.5%) Still more than you want to loose but this clearly shows the green bounce dichro is better at bouncing blue than the blue one!!!!

Rob

[carmangary]

FWIW I have an EO blue dichro and I don't get much loss at all bouncing off of it. Most of the losses I am seeing in my projector are when passing through dichros and when bouncing off my galvo mirrors.

[laser steve]

I found with my old dichro,the blue was superb at bouncing. but the passing through of the green ment i was losing over 400mw. edmonds boast, 98%+ reflective of bounce colour. and less than a 10%loss on transmission of all other colours.

by the time my green went through its old reflect green and transmit blue dichro's then through the other mirrors and galvo. my total output from the front window was a tiny 150mw ish.

[carmangary]

Sounds about like what I have going on. Combined total power from mine is 300mw but I only get about 100mw out the front. Cleaning my optics should help some, though. I have some serious speckle and halo going on.

[steve-o]

Wow!
As usual, a lot of great and useful information. Thanks, you-all. My Blue LaserWave 100mw and Lasever green 80 are superb, but my reds (home-brew 636nm) are brighter than 660 but a weaker visible beam compared to the other two, so they will probably be last in line right next to the galvos. That's going to simplify my layout though; especially because I havent started building the 2nd red yet.. As far as the blue dichro goes, I guess I'll just have to live with the losses and buy 1 from Bridge as soon as I can scrounge up some spare green

[mixedgas]

Wow!
As usual, a lot of great and useful information. Thanks, you-all. My Blue LaserWave 100mw and Lasever green 80 are superb, but my reds (home-brew 636nm) are brighter than 660 but a weaker visible beam compared to the other two, so they will probably be last in line right next to the galvos. That's going to simplify my layout though; especially because I havent started building the 2nd red yet.. As far as the blue dichro goes, I guess I'll just have to live with the losses and buy 1 from Bridge as soon as I can scrounge up some spare green

The offer still stands, ship me a dichro, specifiy a angle, and I'll run it through a spectrophotometer. Enclose a self addressed box and return postage on the box. Takes about a day. No dichroms or mirrors smaller then the spectrometer beam diameter of 7 mm.

Steve

[liteglow]

EO ? Edmund Optic.... ?

But yes I did buy some optics from him..
Basicly I did buy 3 diffrent mirrors..
But found out whatever I did do, there was no need to use the last one

Anyway, my setup is green goes last, then red joins, and then the blue is last lasers that reflect into the galvo !

Have not measure the blue after the dichro, but to my eye it does not look like a huge loss of power... less than 1-5mW