Compact, low power, inexpensive RGB or RGV - is it possible?

[mados123]

Hi guys. Full disclosure ahead - newbie to the Forum and the world of lasers and by the advice of drlava (after signing up for his recent group buy) it was suggested to post my question here. First off though, thanks in advance for considering this thread. Here it goes:

As stated in the title, I need to know if it is possible to design a system with the the outlined requirements, and if so what parts would be suggested and where should I consider obtaining them? As a reference, attached is a commercial one being offered using the 405nm.

1) I would like to have it in a design like the one mentioned below using a x-cube (cross prism). Is that practical?

2) I need to have the combined output of light to be around 50mW.
3) To keep cost down, can a 405nm violet diode be used with the right optics? My budget for optics and laser diodes is around $750.
4) Lastly, what are your thoughts on the system in the link below?
http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=001

Again, thanks for your time and I look forward to hearing from you guys.

mados123

[Laser Ben]

You can't use 405 as a replacement for a blue. It is too low on the chromaticity chart. You need to plot 3 or more points on the enge of this chart. You connect the dots and make a triangle You can get any color inside that triangle. You can't just put three dots. They have to between 430nm and 680 for it to work properly.



Also, don't buy that Aixiz system. It's TTL, on/off. You want analogue that can do 0-100% power based on a 0-5V system.

[mados123]

Thank you Ben for your reply. Please excuse my questions if elementary, but how is it the system in the attached pdf has one configuration using the 405nm wavelength? Are special optics being used that allow for the 405 to work?

Regarding the Aixiz system, (1) is there a significant difference in price regarding TTL systems and analogue and (2) can either TTL or analogue be used for strobing ability and brightness adjustment with the correct circuits used?

Thanks again.

[Laser Ben]

You can ONLY adjust the color balance with a Analogue system unless you want to modify a power supply to change the diode current. You want Analogue for sure, no doubt about it. The system you are looking at is probably not designed for something that is visually pleasing. The 405 is not used for color matching.


As for the price difference, there is a large one for some reason. The only change is a small circuit difference. If you are looking for low power, you can contact uk-laser here and ask for Die 4 Drive systems. Basically, small driver boards with analogue modulation and up to 2A output IIRC.

[buffo]

Mados123;

The .pdf you attached shows several different models, with blue wavelengths available from 405 nm all the way to 473 nm, and red wavelengths from 635 nm all the way to 685nm. Clearly, you select the wavelength you want and they build one to suit with the correct laser installed.

As to why they have one with a 405 nm diode in it - that's anyone's guess. Ben is correct, 405 nm will not give you very good color balance because a large portion of the color chart will lie outside of the triangle between the three points (405, 532, and 635). It *will* work, it's just that you will loose a lot of common colors. (405 nm isn't really blue - it's more of a nearly-invisible violet. Think "black light laser" and you've got the idea. So you don't have a real "blue", which means you don't get "blue-green" either and your white is going to look funny.)

As for optics, you have a number of choices. The X prism is one option, a trichro is another option, or you could use a pair of dichros like the unit in the .pdf file uses. (Note the geometry of the fiber feeds from the three lasers; that combining block has a pair of dichros inside it.)

It would be helpful to know what your goal is. Are you trying to build a laser display device? What are you going to use the white light beam for? Do you care about perfect color balance? Do you care that some of the lasers may have different beam specs (fatter beam, or greater divergence) than the others? And do you need to be able to vary the intensity of the white light beam between zero and full power, or is full-on, full-off only control enough for your needs?

Adam

[Laser Ben]

I've delt with this for him. It's an illumination source for a device.