Laser Burnt off!!!

Well firstly this is my first post.....so i am really sorry if in the process i break any rule....

i am a novice to Laser.....i extracted red Laser diode from my DVD writer which is >=200mW.....we want that Laser diode for our project work(its a part of project)....yesterday when me and my friend were working on the Laser it just burnt off and now it is just emitting dim red light....what we did is that we connected the Laser Diode directly with the 4V Cell phone battery without any circuitary or resistors and kept it on for around 15-20 seconds.....it was ok for that period of time but it suddenly got dim....

we searched many forums and figured out that maybe we gave too much current to it.....

was browsing through the internet and found this forum really nice....can somebody please help us in rectifying the mistake we did....we can afford more Laser Diodes,but can somebody please help us in finding the exact(optimum) amount of current we need to pass through our Laser without burning it and also can anyone tell us how to connect our Laser Diode extracted from 20X DVD writer through Heat Sink....

your advice will grealty help us....

thanks in advance....

You answered your own question. You connected it directly to the battery which is why it died. You need a driver to regulate current, or at the least, a resistor.

Also, depending on the type of diode (open can or closed can?) I would run it anywhere from 200-400mA

i dont know much about the driver circuits or anything like that,can you please help in this regard??

You need a laser driver to keep it running properly, I owuld suggest buying a LPC-826 diode, and also a driver of your choice and run it at about 300-400mA for about 200-300mw of power

thank you so much for your replies.....the problem with me is that i dont know much about Lasers and nothing about their drivers.....i studied about Lasers 3 years back when i was in 1st year of engineering(being a computer science engineer,the Laser was not the subject for me).....but now i need a laser for my project.....

can you please tell me the exact driver circuit that will work for me and also about the heat sink??

grab a GhostDrive from lazorlabs (google search) it's the cheapest driver I know that works well, if you want to spend a bit more, contact flaminpyro and get a flexdrive, then install the diode into a aixiz module head, then solder on wires from the diode to the corresponding wires on the driver, then solder 2 wires onto the drivers battery input, then all you do is touch the 2 wires to a battery and you have light! simple

thank you so much....i am googling it...

one more thing i want to know is that does the DVD writer Laser Module also have heat sink in it or i need to add heatsink externally??

depends, if your planning on putting your laser into a host (flashlight) then it would be best to get a custom one made, contact Eudamonium for one, but if you want a project box or something, then just buy any heatsink of any size, aurora c6 ones are the most common, so you might be able to find some for $5, but usual price is $10

actually i am planning to make Laser Harp....almost made it and tested the other parts of the project.....i am left with the laser part only....

the specifications is that i need to turn on the Laser for 2ms and then turn it off for 3 ms and will repeat the sequence again and again....

now for this purpose do i need an external heat sink?

general rule is you need a heatsink for all laser diodes, otherwise you will have a really short duty cycle, and risk killing the diode. Also, check your pm's

Yes you should get one.

Edit: daawood beat me to it

i googled this...

Laser driver - It can be done

what say???

Up to you, do you want a professional driver or a homemade one

I suggest you buy a Green Laser Module of about 100mW , it already has driver on it you just need to feed it 3.7-4.2V for operation.. Buy a nice heatsink.. Thermal dissipation is the key for long runtimes like 3-5minutes. If you want more , use BIGGER heatsinks.

Read these threads, it will help you with the build.

http://laserpointerforums.com/f51/i-want-build-laser-thread-52972.html
http://laserpointerforums.com/f67/how-laser-diode-drivers-work-explanatory-thread-71513.html
http://laserpointerforums.com/f44/how-select-your-laser-parts-73851.html