Homebrew PCBs

>I was planning to use one that I believe comes from a Blu-ray device.
> I believe that the one used for recording in early CDR's was IR, but
>I don't know so much about more recent DVD, Dual layer, and high
>density recording devices.

     Yeah, generally CDR = IR, DVDR = both IR and Visible red, in two 
separate diodes, Blu-Ray = red and violet in the same component. - Insert 
laser safety paragraph here - .

     Interesting links:

http://www.fineartradiography.com/hobbies/lasers/blu-ray/index.html
http://www.die4laser.com/dvd-rec/DissectionofaDVDwriter.htm