If the driver is a proper one, it will give the diode the same amount of current no matter what the input is (as long as it meets the minimum requirement). The excess will be released as heat through the driver. So assuming it has a good driver, feeding it more current won't increase power output, but it will heat up the driver.
But I doubt the DX/Radioshack type lasers have a real efficient driver so adding an extra battery could kill the diode.
But that is interesting how much that little 5mW could take. The IR filter must have been connected to a photodiode. Removing the filter reduces obstruction to the beam, which lets more power out. If the photodiode was working, severing the connection could have led to an increase in power, because they are meant to monitor a fraction of the output power and adjust current to the diode if the power is too low or too high.
Unfortunately, the IR that your laser outputs is not enough to increase the burning power of you laser, so if you still want an IR filter for safety, installing one won't make the green light any less powerful (besides the <1mW that will be reflected/absorbed by the filter).
Putting more current through it will likely cook your diode. I think you have reached the maximum your little laser can handle.
Pullbangdead:
Yes that is reasonable, however I was only trying to illustrate that using IR goggles for 5mW of excess IR from his pointer is excessive.
It's just that the whole IR thing is blown out of proportion. Yes, it is dangerous, especially if you are very new to lasers or dealing with high powers, but it's not dangerous enough to require safety goggles for a 5mW green.
And yes, sometimes I use a video camera to view the IR, which I should have mentioned.
My pump diode example was just meant to say that even with something considered very dangerous, it can be used safely. Just like a gun, the most dangerous tools can be made safe to operate without a basic "safety"- given the proper level of maturity, precautionary measures and sense of responsible use.
To rephrase:
The IR output from a 5mW laser is not enough to cause damage.
Goggles are good for safety, but if you can't afford them, they are not completely necessary as long
as you take proper precautions and have some idea of what you are doing and take the proper steps to avoid accidental eye exposure.
Even though I never use them, I still recommend them for anyone who is unsure of the real dangers.
Hope that clears things up.
Oh- and the whole multimode diode thing; multimode diodes seem to diverge more than single mode diodes so I would assume they pose a smaller threat. There really is no significant difference, but there is a difference nonetheless.