Green laser help?

[Georgy291]

I recently bought a green laser pointer from ebay, its 5mW power, but i know that the 5mW lasers are exactly the same diodes that are used in the 20mW, they are just limited to 5mW so that they could stabilise the output power on them.

Here is the tricky bit

I can re desighn the contol circuit for the laser so that it outputs the full 20mW from any powersource between 3v and 30v

the only thing i need is the circuit schematic for the original control board, its a pain in the backside to draw it out since they done a nice job painting over it

if anyone has done a similar thing to this before or knows any information that could be helpfull id realy appreciate it

thank you

PS if you want i can try to post the new control circuit so you can try modifying your laser to

[Mousemat]

Well, that would put it over the general public legal limit. In fact I think the limit in the UK was reduced to 1mW because of all the idiots who thought it would be a good idea to shine them at pilots. IIRC the higher power ones have to be registered.

[Agent]

There is normally a resistor on the board (SMD) - kill it with an iron / bypass it.

[Whiternoise]

If you bought it from eBay it's unlikely it has anywhere near 20mW - the diodes are crap. If i recall correctly, most 5mW ones almost never reach that. If you want a decent (stable) power output, the only surefire way is to buy one that costs a fair bit more i'm afraid. Some of them will have potentiometers inside them, so you can just pot mod it. Failing that, how about just removing the diode and wiring it up to a voltage supply directly (with a resistor of course).

http://www.wickedlasers.com/ are some of the best.

[Stoo]

I keep meaning to buy one to mount on my telescope to aid calibration

Edit: Hahaha, Photonic Disruptor!

[Georgy291]

thats exactly what i done today,

took the diode out,
and fond out that it works in a rather different way
it first consists of a infared laser off 808nm then it has got a crystal thats green in colour and couses the 532nm light

i measured the current going in to the control board to the diode and it turns out its 250mA and it runs from 1.5V
do the math 1.5*0.250 and you will see its slightly 5mW already, having done this
i desided best thing to do is to make a different current source and leave it there.

As for the pilots, LOL who would be stuid enough to do that?

il poston the new idea for the current source tommorow, since i cant find the data sheet for the controll chip right now

[Blaineoliver]

Yeh give it a go!

[SamanthaCarter]

I've had pretty extensive experience modding green lasers in the past. It is not anywhere as simple as you make out. The diode is NOT the deciding factor on the output of a green laser.

DPSS - diode pumped solid state. These 532 nm wavelength green lasers use infrared diodes shined through a collection of very expensive crystals - to get from 808 to 532nm. Crystals vary in quality HUGELY. Also- power output is NOT linear to how much you pump through the diode. Crystal efficiency may be infact, higher at lower current draw. Usually the circuits have a built in potentiometer. But if not- selecting the correct resistor and finding a suitable one as replacement may increase power output.

Check out www.greenlasers.co.uk.

Through the leadlight 105's have sort of phased out of existence with the introduction of very cheap, low quality, misleading power output designs (IR filter removed to mix the green with infrared (to burn stuff..very dangerous and not any brighter)) maybe you can learn something from the guides which are already there. I hope this helps. Again, I stress...DPSS modifications is not simple, at best...it's a lottery.



Mid powered one that i modified from 5mw to about 35 in this case. My best mofidication took a <5mw to about 65 peak - stable 50mw. It was friggin intense.

The pointing at air planes thing is somewhat of a myth. Unless you're standing on a run way shining them at pilots while they take off. Over 30,000 feet the beam divergence (~1.5mrad) is pretty huge and over that distance a 5mw laser isn't really going to get very far. Sure they'd see a small green flash on ground level. Nothing worth shielding the eyes for...

[noTHINGface]

.. For what purpose? Is this a 'cos I want to and I can' thing?

[SamanthaCarter]

so you can have a brighter beam which is more viewable to otherpeople when you're pointing at the sky showing constellations cause you take an interest in astronomy?

That's not me though I did it because it was interesting and I'm now an electronic engineering under graduate student.

[watercooled]

Make sure your ebayser has an IR filter - lots don't and the emitted IR laser light can cause permanent eye damage. More expensive lasers are more expensive for a reason - they use high quality diodes and have IR filters so emit only tiny amounts (if any) of IR. I'd recommend wickedlasers.

[Whiternoise]

The pointing at air planes thing is somewhat of a myth. Unless you're standing on a run way shining them at pilots while they take off. Over 30,000 feet the beam divergence (~1.5mrad) is pretty huge and over that distance a 5mw laser isn't really going to get very far. Sure they'd see a small green flash on ground level. Nothing worth shielding the eyes for...

They're not talking about cruising altitudes (i would be seriously impressed if someone could hit a plane from ground level to 30k feet up with a laser dot..), they're talking about low flying (most often police) helicopters, planes on final approach/take off and generally low flying aircraft where you're under i reckon < 3-5000ft (ie mostly under a mile up) and you don't really want a flash in your eyes because it can throw your awareness in a second.

This is the danger, yes you would have to be at the end of a runway to do it - but what if a group of idiots thought it would be fun to do next to Heathrow?

[Funkstar]

The pointing at air planes thing is somewhat of a myth.

Quite the opposite.

City plane scare brings action call over sale of high-powered lasers

[Lee H]

That's not me though I did it because it was interesting and I'm now an electronic engineering under graduate student.

Aww.... I thought you'd be doing a Ph.D. in Theoretical astrophysics with a name like that

For those who don't watch star-gate... you'll not get that reference

Lasers are something you need to be careful with. there was a case recently of lots of Russian Ravers having eye issues due to the wrong strength of laser being used for the light display at an event.

[SamanthaCarter]

Aww.... I thought you'd be doing a Ph.D. in Theoretical astrophysics with a name like that

For those who don't watch star-gate... you'll not get that reference

Lasers are something you need to be careful with. there was a case recently of lots of Russian Ravers having eye issues due to the wrong strength of laser being used for the light display at an event.

hehe, if i knew there was a Samantha Carter equivalent in existence...I would =D Besides... Samantha Carter is way too clever *sniff*. She'd breeze through my course at about 15 years old even though it's thought to be the hardest engineering faculty at my uni (imperial college).

Theoretical Physics is intense though. To be at the top of it...literally the hardest field in existence i reckon.

[greenalien]

http://www.photonlexicon.com/forums/index.php is a great resource for all things laser...