Source for cheap low power lasers w analog mod (and RG[B/V] mw power pairing values?)

[macpod]

Hey folks,

I'm designing some open-source usb laser showcards. When the 2nd pcb version gets back from fabrication, I'll post more about that. I don't like to release things till they are done...

While I wait for the pcbs to be fabricated, I need to get some lasers! I have a 50mw green laser pointer (no modulation) that I used for initial testing and found if anything, that it was too bright so I would like to stick with this power level... what I need now is:

1. What mw power red and blue/violet lasers values should I be considering to pair with a 50mw dpss green laser? Is there a general rule of thumb?

2. Where can I get a cheap 50mW green laser with analog modulation? Any color would do really, I just need something to test the analog circuitry. Thus far I haven't found anything pre-made.. It seems like buying a laser pointer module (~15 bucks off ebay), removing the power circuitry, adding an IR filter, and then make my own own driver will be the cheapest. I'm quite surprised there aren't more cheap pre-made analog drivers out there. I'm an embedded sw engineer more-so than an ee, but it seems like an op-amp that controls a mosfet (with feedback via a shunt resistor setup) and perhaps some adjustment/safety circuitry should be enough?

Thanks

[slicklasers]

Flexmod P3 and the Quad Drive from Badip are some of the analog drivers already out there, easy and cheap...

[macpod]

Thanks slick. I just took a look at these two drivers. Looks like the flexmod is out of stock and the quad drive is a bit high in price. Are there any out there for lower wattage lasers that are less expensive?

Just based on components I see in the pictures (big honkin resistor and a fet), it looks like their drivers work exactly how I was thinking of making mine (except theirs have more bells and whistles)

[edison]

There is also a dual version available (quad driver split in half ) You can driver also 2 diodes in series if nessesary. The dual driver has also beamsupression. The quality of the drivers are very good so its the best option

[LaNeK779]

You can match your green with 50mw or red and 50mw of blue (or slightly more)

a good source for diodes would be here (member DTR)

https://sites.google.com/site/dtrlpf...m-pl450-diodes

https://sites.google.com/site/dtrlpf...le-mode-diodes

[macpod]

I've done research on the color thing and find everyone is using much higher blue and red values compared to green power value. Are you sure 1:1:1 ratio for rgb would work?!

[LaNeK779]

I've done research on the color thing and find everyone is using much higher blue and red values compared to green power value. Are you sure 1:1:1 ratio for rgb would work?!

no i am not, as my set of eyes may work different to yours in terms of what is white (and i mean this literally, don't think i am joking).
but many people here tend to favour this analogy

in case i am wrong, the red diode i linked above can go up to 110mw and the blue can go up to 80mw, so still you're ok

[kitatit]

+1 for what Chris said. Those diodes he linked to would be great. If you are using it for beam show maybe more blue, but for graphics this will be a great match. Also as Chris mentioned the little 445nm blues can easily do 80mW. Regarding the red, at 638nm you will have plenty of red. With all these at full power it would probably look slightly pinky/reddish but you will have plenty of room to tune a perfect white with this combination.

Good Luck
Kit