Laser keeps me awake most of the night

[stanwax]

Ok chaps I was waiting for someone to pick me up on this. Yes I guess the Blue is most precious but I did a load of tests at the weekend - and repeated them over to measure the pass and bounce percentages of each dichro with each wavelength. From this I have concluded several things which I will write up at some point - one being that the layout that looses the smallest amount of photons overall is the one I have gone for. Trust me there has been a great deal of consideration gone into the layout. Though the blue beam looks bright its actually only about 2% of the blue beam overall - this is off a green reflecting dichro - if I had done it the other way with green through and a blue bounce dichro then I would have lost 15% green and about the same 2% of the blue - though ther is a way to improve the blue dichro perfomance which I will reveal when I write my results up but was not practical in my layout and the limited space I have.
Also yes the white beam does bounce off a 45 degree mirror and yes there will be a loss but can you suggest a way of getting the beam into the scanners any other way! without me having the lasers off in thin air to the side. Plus there is a big advantage as this is an adjustable mirror so it allows you to fine tune the position of the beam hitting the scanners to make sure its on target.

been finishing the dichro adjustable mounts tonight to get rid of some of the blu tak

Rob

[stanwax]

here are a couple more pix of what its doing tonight. First shot shows assembly with new optical mounts - still held down with blu tak - the others are just some nice fx
Still far from finished but Im bloody made up with it!

Rob

[Pitts]

Hi Rob,

Thanks for taking the time to explain your tests.
I look forward to your article on the how's and why's .
This is great timing for me as I am just starting to work on my layout setup so any info is readily absorbed.. ( read "Needed")

Thanks
Ray
NZ

[chad]

Those pictures are great!! Perfect smoke, awesome color!!

chad

[allthatwhichis]

I really like that orange!!!

[stanwax]

I really like that orange!!!

So do I

actually thats not a bad representation as the camera often distorts the colours - show them different from how the eye percives them - so I was pleased with how it looked on the camera as well as in real life.

Rob

[stanwax]

Some more pics - I just cant resist! Now the lasers are all screwed down as are the mirror/dichro mounts - just the turning mirror that sends the beam to the scanners to sort tonight

Rob

[p1t8ull]

Great colour balance there Rob.

What power is each laser spitting out? I seem to remember from the UKLEM you saying you had:
~350mW (was it?) red @ 660nm (ish) from your nice homebrew dual diode
>100mW blue (120mW?) from Fluff
...and how much green in the mix?

[stanwax]

The green is 80-100mW depending on how its feeling - its an old passively cooled CNI but has been a good old soldier and there life in it yet. Red about 320mW at the cube and the blue is around 100mW though Its a little unstable when being blanked but im hoping this will improve when It goes to analogue blank with threshold setting - so the diode never turns off.

Will post more pix when I get the rest of the electronics built and mounted and the thing doesnt look like its guts are hanging out

Rob

[p1t8ull]

Another quick one;

Have you measured the amount of loss of red off the 6800 mirrors out of interest?

I know there's been talk of the CT mirrors (in fact all scanner mirrors) losses, but I tested my RGB recently and found that with 350mW of ~660nm red measured immediately before the 6800HP scanners, after bouncing off the x/y mirrors I was only getting 280mW out.
Green and blue had much lower (acceptable) losses.

Perhaps the coatings reflectance curves are starting to rise at the longer wavelength, but it really doesn't look like mine is transmitting ~25mW through each mirror.

Just wondered how yours compared?