homemade red laser

[Thories]

Hello hello, i have a dvd reader/writer that i am very happy to sacrifice for a laser diode. ( how amazing just 3 weeks ago i did my first internet search on lasers now I've got a 50mW green laser in the mail and hoping to make a red one ) anyway i have some questions. Is there a way to find out if the laser diode is suitable (like not all IR) without opening it up. also I'm probably going to need some general help with designing the circuitry (does anyone have some general guide??) i have a basic understanding of some simple circuits ( amplifiers & rectifiers... doorbells and such) and i can assemble circuits well its just i have very little (Ok none) experience with laser diodes and the related circuits. OK i know this sounded noobish lol.... anyway any help with this will be really appreciated .

 

[SenKat]

Check out my post in the experiments and mods section regarding DVD-diodes !!

 

[Thories]

hey thanks, very useful however now i need some more help . i opened up the dvd writer and extracted the laser diode in its little module thing o.... I've found some stuff that looks like model numbers on it, so i googled it however i cant find anywhere that states the voltage that it needs or anything, the numbers are. KWS-280A and below that, there is D256511B there is also allot of stuff that looks like allot of squashed Chinese characters. i really cant get over how tiny the diode must be... like the lens seems to be 3-5 mm across... though i suppose they are pretty tiny.... anyway what should i do with it next, cos i don't know what voltage it needs or anything...

just a min... just checked another post....is there 2 diodes in the dvd burner/reader..... i suppose that would be logical...... i only saw one while in there tho.....

 

[SenKat]

Someone else posted here, or elsewhere that they could only find one diode in their dvd burner, too - makes me wonder if they are using combo diodes now - similiar to the blu-ray diodes that have red, blu-ray, and IR all in the same can ???

 

[Thories]

eek that probably means the laser will be quite dangerous right?
....wait tho this dvd writer is over 2 years old.... hmm odd

 

[SenKat]

Okay - in the optics carriage assy, there is a couple of cube beam splitters. Find them !
Now - to locate the diodes - look at EVERY side of the cube - follow it out to the outside of hte assy - you SHOULD be able to see the other diode.....look at it closely....

 

[Thories]

sorry im very new to lasers..... i cannot see any beam splitters, all i can see is one lens, i assume to get to the diodes i gotta dissect the part that was on the slider? and the splitters will be directing the diodes to the main lens? lol very sorry for lack of knowledge only been looking at lasers for bout 1 and a bit weeks

 

[SenKat]

No worries ! you are doing wel - yes, on the optics sled - you will find the main lense - remove that. Underneath that main lense, you will see a series of glass blocks (beamsplitters) that you can use to locate the diodes.

 

[Thories]

ok ive gotten to a big bluish glass block, is this the beam splitter?

 

[SenKat]

That is one of them - look on all four sides of that block - imagine a laserbeam bouncing off of it - follow it back to the source diode....

 

[Thories]

oh wow.... i got the back of and its amazing, ive found the two diodes, hard to imagine they were once playing my games .... one has a glass block on the front and one just a bluish lens

 

[SenKat]

Saweeeet ! You found them ! Allright - now make your laser !

 

[Thories]

thats an awsome thing to hear... now getting the things out, how sensitive to heat are they. Is there a safer way than de soldering?

 

[SenKat]

Use solder FLUX when you desolder the diodes - make sure to use a suction type desoldering iron, make good use of your brain - the primary failure reason for didoes is heat - you don't want to kill it before it even gets out of there ! Yes - they are very sensitive to heat - be cautious, take your time....half the battle is removing the diodes, once you get them out, the rest is cake ! Put hte flux on the solder joint, and apply high heat for very little time - if it is down to one connection - put hte diode in a GENTLE clamp, and pull away the offending wire, or mylar connection while you desolder - so you most likely will not need a desoldering iron at that point. TAKE YOUR TIME !!!!

 

[Thories]

thank you sooo much you are a CHAMP! i shall de solder tomorrow as its nearly midnight here..... i will take my time, to get them out.... i imagine i shall be online sometime tomorrow to say how i got on after that ill just need to make a simple circuit and put it into my stylish bright orange case.... *cringes* anyway thanks a HEAP dude i really cant thank enough. but now i got to go to sleep.

 

[Thories]

uhhh question, are laser diodes sensitive to static? should i be treating this in a special way...?