Help build Multi colored/low power/low budget Laser

Greetings,
I'm new to the laser arena but have some skills handling electronics, building and modifying LED flashlights etc...

I now need a compact handheld laser for short range experiments in my lab.
It requires a good visibility 532nm Green and 650nm Red (~5mW) and a bit stronger 405nm violet (10mW-20mW !?).

It doesn't have to be too fancy - I don't need to burn anything, have extremely long range or operate these for more than few seconds at a time- just an elegant and compact as possible device I can carry around for demonstrations.

From looking around the forums here I saw many COOL projects with some clever ideas - but mostly way too powerful or too big for my needs.

I saw few of those 2in1 pointers at DealExtreme/DinoDirect for $20-30 - but they only have 2 colors (usually Red/Green or Blue/Green).

So I wondered if its feasible to house 3 small modules inside one of these compact $2 9-LED 8000mcd White Light Flashlight with DX Logo - Black (3*AAA) or the multifunction 2-in-1 7-LED Flashlight with Laser.

Can anyone recommend a suitable setup/ host/ laser modules source for that small project?
I'd like to keep it as compact as possible and on tight budget (<$30 !?).

Perhaps even getting cheap pointers as a source for the laser modules etc...

Thank you guys for the help and happy holidays,
Gal

That would take a lot of work to put all 3 in 1. Try this Purple/Green/Red Laser Pointer Combo 3 Pcs US TOP SELL - eBay (item 280578085711 end time Jan-18-11 13:33:53 PST)

Thank you for the fast reply :thanks:
I don't mind investing some time and work - it's part of the fun and usually a great learning experience.
Having something unique worth the troubles if I can do it myself.
The linked items could have been a good source for the modules but are not powerful enough...
So - any other insights/recommendations?
Gal

The violets have been averaging 45mw and up to 70mw, some of the greens have been upto 100mw and the red I can't remember. They are all way over 5mw.
Do a little research on LPF and you will find that with the change of optics and the violet will burn things.

If all you are interested in is three different colored dots then the three different laser pens that is on ebay should work, now if you plan on having them blend there colors in one dot then you will not be able to realize that for $30.00 sorry...

gal said:

I'd like to keep it as compact as possible and on tight budget (<$30 !?) Gal

Click to expand...

30$ Will get you three China pointers and two rubber bands.

der ya go!!!

Guys - were's your Xmass spirit :san:
I don't need to mix colors into a single beam- just having a compact and elegant device with 3 colors ...

I'd settle with this if it was a bit cheaper 2 in1 30mW 532nm &30mW 405nm Mid-open Violet Purple Blue and Green Laser Pointer Pen (2 x LR1 Batteries Included)

How about modifying this one by replacing the LEDs with small RED and GREEN lasers: 3-in-1 50mw 405nm Handheld Violet Purple Blue Laser Pointer& 6-LED Flashlight - not that compact but perhaps easier to mod?

Any creative ideas?
(Preferably w/o using rubber bands...:crackup

...I hope I won't be baned from this forum due to limited budget and low power requirements...

Thank you guys,
Gal

Well, if you don't want a full RGB set and is enough a pointer where the color can be changed almost linearly from two, like red and blue, as example (and overall, low powered), you can use one of my designs ..... mix red and blue with a PBS, and then place a polarized filter in front of the assembly.

Cause the mixing of the two beams is made from a PBS, one is polarized horizontally and one vertically, in the beam, so rotating the front polarizer, you can change the color almost linearly from red to blue, cause the polarizer left pass different percentages of the two wavelenghts for different positions ..... ofcourse, the power is low, cause you may have less than the 50§% of the total power out from the polarizer, but the final effect must not be so bad

With red and green, it's a bit more difficult, cause usually green modules are not polarized stable and constant and predictable, so the final result can be weird someway.

RGB can be done too, but it requires bigger diameters and some complex optics alignments ..... i have plans for similar "toys", but no access to machines, and around here machinists asks you a lung and an eye, for works like the ones i've designed, and i don't have money, so, for now i'm stopped

Thank you HIMNL9 for the insights
I don't really need to mix the beams together - just be able to project these 3 different wavelengths from a single convenient device (I use it to demonstrate different particles inside aquas suspensions and excite various Fluorescent materials).
I'm actually able to do some machining myself - perhaps not producing the whole thing as professionally as things here are done - but more than enough to modify a decent host for the laser modules.

My main challenge currently is to figure out the correct configuration of modules and power source to fit a compact as possible host - and to source the required components.

I have few Red lasers and flashlights around to experiment with - but still look for suitable Violet an Green modules to go with...

Any good deals or ideas for a suitable host and laser sources?
Gal

some of the multiple LED flashlights have a large enough head that a machinist could fabricate a heatsink that can accommodate 3 Aixiz modules. Check with one of the Guys in the Laser PRO Shop section, and I'm sure that You can come up with something.

Well, if the main purpose is to use it as demonstration unit, the more easy way for build it is using a small project enclosure, not a pen/flashlight style handheld pointer .... i planned it in the flashlight style for the purpose to mix the beams, but for separate beams, it's a waste of time, money and efforts, imho, to do it in the more hard way .....

For this type of use, a small SC700 box (like a cigarette pack, just a little less) can hold 3 modules one near the other (and a heatsink, if needed), the batteries, and all the rest of the circuits, and still remain some space

Well... I guess it doesn't HAVE to be pen/torch style...
But still need to be handheld conveniently and as compact as possible (to carry in a big pocket !?)
Can you give me links to suitable "enclosures"?
I'll prefer something a bit longer and thinner than short and thick p)
Gal

The closest thing you'll get for $30 is buying three laser pointers (or a 2-in-1 and a second) in those colors and taping them together so they look like one. Otherwise you're going to be overbudget trying to source hosts, power supplies, batteries, etc. to get it to work.

I'd just buy a 2-in-1 red/green, and a violet, preferably Newwish-looking models (#1, #2) so they're roughly the same size. Then get some electrical tape and tape them together. It'll be a 2-wide laser pointer with three buttons. The violet lasers are usually always overspec (10-30mW), but even so, will still look dim compared to the red/green because of our eye's color sensitivity.

the ones i was referring are these ones (page in Italian, sorry i can't find the equivalent in English), but i suppose any case that can hold 3 modules and a pair of CR123 batteries can be ok .... there are also smaller ones similar, like this one, or this one, or this one, but then you need to check if the inside space is enough for hold all .....

Well... After looking around a bit more - it does seem to be cheaper to buy ready made pointers, take them apart and host the internals in a nicer host of some kind (perhaps build myself from Alu. profiles or something...).

I still wonder if at a similar budget I could find decent modules of 5-10mW Green and >15mW Violet that can be operated from the same power source (2-3*AAA / 2* CR123!?) and offer a bit more flexibility with adjustable optics etc.. - which modules would you recommend and where would be a good place to source them?
(Assuming I'll recycle the Red laser, host and other parts from what I already have).

Or is it too much to ask for ~$30 ?

Any good offerings somewhere?
(there are so many "sales" that I'm a bit lost...)
Gal

Not sure, but, i think that for modules alones, there's not too much flexibility, if wanted for use them with the same power sources (almost all 3 to 3,7V for greens, and different values for reds and violets) .....

In this case, the cheapest solution can really be the one to get some cheap "newwish" style pens from ebay, dismantle them, and use the inside modules, cause basically all them are planned for be used with 2xAAA cells, so it can be enough to use a single CR123 (or a rechargeable CR123 with a diode in serie, for the 3V), with independent buttons (CR123 just cause so it can be built smaller than with a pair of AA cells, but can be also used just two AAA cells, if the case is too low)