Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



My take on a quad red

andy_con

New member
Joined
May 24, 2007
Messages
3,394
Points
0
Nice setup! Nothing wrong with scrap metal, it looks good.
Are you going to post some burning?

i didnt build this for buning, i built it for my projector.

Very nice setup! It's funny that red is now the limiting color in hobby RGB laser systems, but it looks like you will have this covered. I don't know if I missed it, but what current are you feeding those laser diodes?

my next re design will be 1.2watts of 660nm with a beam of 3mm by 3mm @ 1mR polarized in one direction. so two modules could be combined together.

dont know the current, but 250mw per diode
 



x90z75ek

New member
Joined
Mar 17, 2010
Messages
217
Points
0
This is going to be in a projector? So you built this setup to match the 1W from 445nm diodes?
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
To match that, i suppose 4 diodes arent even enough to get proper white balance - but its a good start at least!
 

AJ_Dual

New member
Joined
Aug 10, 2007
Messages
527
Points
0
This is going to be in a projector? So you built this setup to match the 1W from 445nm diodes?

To match it from a viewer's color sensitivity standpoint you'd need somewhere around 10W of red!

I hope the screen is made of something suitably heat resistant. LOL... Although seriously, scanning at whatever the video refresh rate is, I suppose dwell time on any given point is pretty low.

What I assume the projector makers do is beef up the red output somewhat to match the blue and green, and then dial back the blue and green so they all meet in some happy medium. It also helps that since the natural human sensitivity to light is for everything, not just lasers, so if you're projecting an image of a red car against a blue sky, it's natural for the car to look darker, so the red does not need to be driven so hard anyway.

LCD and CRT's don't need to do something special to make the red dots brighter AFAIK, so presumably a laser projector is no different.
 

andy_con

New member
Joined
May 24, 2007
Messages
3,394
Points
0
To match it from a viewer's color sensitivity standpoint you'd need somewhere around 10W of red!

I hope the screen is made of something suitably heat resistant. LOL... Although seriously, scanning at whatever the video refresh rate is, I suppose dwell time on any given point is pretty low.

What I assume the projector makers do is beef up the red output somewhat to match the blue and green, and then dial back the blue and green so they all meet in some happy medium. It also helps that since the natural human sensitivity to light is for everything, not just lasers, so if you're projecting an image of a red car against a blue sky, it's natural for the car to look darker, so the red does not need to be driven so hard anyway.

LCD and CRT's don't need to do something special to make the red dots brighter AFAIK, so presumably a laser projector is no different.

WTF...

10watts of red......

where did you get that figure from?
 

AJ_Dual

New member
Joined
Aug 10, 2007
Messages
527
Points
0
LOL, sorry, I was thinking automatically of the 1W 445's everyone's talking about. I completely skipped past that you'd be using 500mW. It would be more like 5W, no?
 

andy_con

New member
Joined
May 24, 2007
Messages
3,394
Points
0
even with 1watt of 445 10watts of red is very OTT

with 1watt of 445 you would need 2watts of 660 and 1watt of 640
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
I suppose 635 and 445 are fairly comparable for brightness/mW indeed, so you'd need double or triple the power at 650-660 to match.

As far as projections go, these ratios are only important if you need maximum-brightness white. An approach often taken is to dial down the green (and now perhaps also the blue) if white is desired, but to crank the green to maximum when just shooting out coloured beams and projections.

Its not that often that you'd require absolutely white light. As long as there are other colors, the white will appear as such within reasonable limits... not because it actually is pure white, but because it is 'more white' than anything else projected.
 

ped

Well-known member
Joined
Nov 25, 2008
Messages
4,913
Points
113
Theroretically....how many more diodes could you add before beam shape/divergance becomes a problem?
 

BShanahan14rulz

Well-known member
Joined
Dec 29, 2009
Messages
3,151
Points
63
If all the diodes in that quad-red brick are polarized the same, you could mount 4 more in a similar brick, polarized 90 degrees off from the first set, and combine using red-coated PBS. Beam profile would be like 2 of the beams in the same place, but one turned 90 degrees.
 

andy_con

New member
Joined
May 24, 2007
Messages
3,394
Points
0
using the right optics you can combine 48 diodes two sets of 24 then use a cube to combine.

but you will run into patent issues doing this
 

Xtrm2Rick

Member
Joined
Oct 6, 2009
Messages
821
Points
18
i once where in the progress off combining a few reds and green modules... but i ran short on funds so it has been gathering dust for awhile and i totaly forgot it

but now you reminded me of it i might go and finish it some day soon i hope.

anyway awesome build man:gj:
 

andy_con

New member
Joined
May 24, 2007
Messages
3,394
Points
0
indeed this is true

seems a waste buil!dig an 8watt red or home use though
 

ped

Well-known member
Joined
Nov 25, 2008
Messages
4,913
Points
113
indeed this is true

seems a waste buil!dig an 8watt red or home use though

Are you kidding??

the brag points alone would be worth it!

Or take it to a show...8 watts...with a set of 30kbps galvos in front of it... <drools>
 




Top