# mods for red lasers?



## silver_pioneer (Dec 7, 2005)

Can red lasers be modified?If you can what will the power level be if I mod a 5mw?


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## AJ_Dual (Dec 7, 2005)

Yes, red lasers can be "modded", but what you can do is limited. Most everything you can do is basically over-driving the diode, which shortens it's life. The red laser consists of a red laser diode and a focusing lens, and that's all.

This is do-able though, because red lasers are so cheap, sometimes as little as a US dollar or two, or a Brititsh pound for a keychain pointer, you might not care if you burn it out while you play.

One of the easiest mods to a red pointer is to squash in an extra battery. This is easily accomplished on the keychain bullet style -pointers that use the tiny watch batteries. Sometimes you can just cram an extra one in, maybe snip off a spring from the battery cap to make room, or use a piece of tape to hold the extra battery on the end, and a small wire to make the contact.

Someone once posted a pointer from the UK that they discovered did have a turnable potentiometer inside, but most red lasers are very simple with little or no components to make them as cheaply as possible.

The reason green lasers can be modded more easily is because there's many steps in the process where you can improve the power. The laser diode is actually infra red, and is a model that's capable of running at several hundred mW so it can "punch through" all the crystals and filters that turn the infrared light into green. It has to be powerful because each step in the process is far from 100% efficient, and you lose power at each step in the crystals that are turning the IR laser light into visible green light. The diode is actually held back by the pot (potentiometer) and resistors on the driver board and turned down at the factory to output the desired <5mW, because they don't know at the factory how well the laser will work until they put it together, so they just turn the pot up or down so it's right. This also makes the "pot-mod" easiest of the green laser mods to do. (If your laser, usualy a Leadlight 105, has an accessable potentiomter you can turn…)

So the diode in these green lasers is much more powerful than a red pointer's diode to begin with, and it's much better able to tolerate being turned up. Then, there are variations in the crystals, their purity, their quality, and how well they line up with the infra-red pump diode, and each other. Each step is a point for potential improvement, or just the luck of the draw where they're all working better from the factory due to random chance.

A green laser is like a car, where there's several places you can tweak things to improve the performance. You can mess with the fuel, the air intake, the fuel injection or carburetor, the transmission gearing, the cam, the cylinders, the exhaust etc. etc. etc. A red laser is kind of like a unicycle. 

The good news is that red lasers, because they are so simple, even powerful ones are relatively cheap. You can buy a high quality and rather tiny 100mW+ module for around $250, all you need to do is hook the wires up to 3 volts of battery current, and you can make a very potent red pointer easily.


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## silver_pioneer (Dec 7, 2005)

This red laser has a pot and a few other things like two tiny transitors and a resistor.I don't know the brand but it cost around $20.Its the pen type of body.I did have a cheap $1 red laser at one time and I overdriven the diode it only lasted a few hours.


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## silver_pioneer (Dec 9, 2005)

I moded my red laser with the pot.Its much brighter but,I don't know how to measure power.Can someone point me in the right direction?


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## marshall (Dec 14, 2005)

Silver Pioneer:

Read the top "sticky" in this forum on green testing with an LED...I would 'assume' the same, or near the same theory applies...you just would need the correct color red diode (no clear diodes). You might want to post this question in that thread (maybe the answer is already there...I didn't get to browse the whole thread yet).

EDIT: 

On a second note guys, I would also assume, based upon diode theory, that if you could 'up' the cooling ability to the red diode itself, it would have much more capability...to an extent that is. Heat created inside the diode (from the reactive element) is the sole destroyer of the diode (right, photonic engineers?). Reason why you use a thermo-conductive grease or glue to attach the diode to the heatsink. If you could pull that heat quickly away, you have yet another added "tuning" ability which isn't normally thought about when working with the 635-650nm diodes. I'm sure you might have heard of thermo-electric cooling, but this is on a whole different level, and I myself don't believe it can be done in a pen-sized pointer (of coarse...as it takes additional power to cool thermo-electrically).

There was a member on here, who, a while back posted pics of a thermo-electric-cooled 300mw greenie he integrated into a Radioshack 'project-box'. Now we have pointers with no need for this sort f cooling, that are getting very near 300mw. I think 500mw+ in 650nm is very do-able from a correctly designed pointer...but others will speak otherwise. Give it time, and good things will arise. I've been battered down by my thoughts of huge outputs I spoke of last year, and now my thoughts are the ones holding true. Mainly why I don't speak too often in here. Sort of like Moores law with computer processors...things will advance continuously, just sit back and enjoy the show.


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