"Jeff Liebermann" wrote in message
...
On Tue, 20 Mar 2012 18:42:03 -0000, "Arfa Daily"
wrote:

Hows about the lens from a an old CD laser ? Just thinking out loud ...
Arfa

Maybe. The common DVD laser diode is 632nm, which is in the visible
light range. Laser printers and CDROM drives are 780nm, which is near
IR. Since outside light sources do not enter into a CDROM drive,
there's no need for an IR bandpass filter. I couldn't find anything
on the optical characteristics of the CD or DVD lens. The dark ones
might be a possible bandpass filter. The clear lenses are probably
not.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


DVD lasers operate at visible red as you say, whilst CD lasers are near IR.
CD laser lenses often appear to be optically coated, but for what reason
exactly, I'm not sure.

Arfa