"Dick Carroll;" writes:

Sam Goldwasser wrote:

(JURB6006) writes:

snip

For example a magnetron could come pretty close to being considered a MASER if
the proper output tubing/system were used. They consider that glorified LED in
your CD player a LASER, but it's not really a laser.

This is simply not true. The laser diode in a CD/DVD player/drive is true laser,
period.

IIRC, LASER means "Light Amplification by Stimulated Emission Radiation".
Can they do all that with a single LED, Sam?

Yes, absolutely. It's not just a glorified LED. It has a laser medium
(the semicondcutor), mirrors (on the ends of the cleaved crystal), and
excitation (electrical current). Trust me, it's a true laser.
Furthermore, it puts out a near diffraction limited beam that can be
focused to a spot less than 2 um in diameter at the surface of the disc's
information layer. You can't do that with any LED or non-laser light
source.

The laser diode in a CD or DVD player or drive is similar to what's in
a laser pointer or diode laser module, a laser printer, and diode laser
based barcode scanner (though the specific wavelengths and some other
parameters differ).

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
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