Running a laser diode without a driver?

Hello.
Is it possible to run a laser diode without a driver?
(I am a newb so I don't know this)

Like the Kipkay way ? That isn't a good idea. It is possible but it can burn out your laserdiode.

http://laserpointerforums.com/f65/direct-drive-445-host-52918.html

It's a good idea to get a driver, just so you don't accidently kill your 45$ laser diode.

It can be done with the appropriate current limiting resistor, but you won't be able to use most of the battery's energy. Once the current output drops it will get dimmer and once the voltage output drops below the forward voltage of the cell it won't lase at all.

With the right resistor setup it should not harm the diode, but if it is off at all (too much current) very bad things can happen.

Drivers are not expensive though, not compared to 10years ago.

Depends on diode .. IR are very sensitive, but 1W 445nm are rather tough. Not that you CANT kill it. But I certainly did a lot of bad things to mine and it i fine. It can survive several seconds of reverse polarity for example (with battery, current driver would kill it).
Then it is all question of obtaining correct voltage. For example 1W 445nm diode works perfectly with 3 AA or AAA batteries, as it's working voltage is around 4.5V. Check my sig. for such direct drive build. It even has advantages - it's more effective as there is no driver and no power loses. On the other hand, the current will get low as the batteries get depleted and you won't be able to squeeze all the juice out of them.
If you feel lucky, go for it. It can be done, and it was done. If you don't feel like blowing the diode, don't do it.

Maplin;

It is fine if . . .

the diode voltage matches up with the peak battery cell voltage.

Here is a thread I did with a 445nm LD:

http://laserpointerforums.com/f65/direct-drive-445-host-52918.html

I have also done them with RED LD's . . .

but a resistor is REQUIRED.

My 1 watt Green matches up with the 4.35 VDC lithium cell overcharged slightly {~4.45}

Also you MUST have a good heat sink to maintain a stable temperature.

LarryDFW