•Small, efficient, cheap
•Only red wavelengths available at reasonable prices
(blue works, but still
problems)
•Mostly made of Gallium aluminum arsenide (GaAlAs)
•Emission ratio is varied by changing the ration of
gallium to aluminum in the
semiconductor
•Main use is CD players (now 2 in every household!! One
in the stereo and one in the
computer! And maybe one in the laser printer!)
•Biggest problem is not power - but lack of fluorescent
probes to be excited at
650-900 nm
•Problem is poor beam profiles for diode lasers
•Noise levels are generally 0.05% or less compared to 1% for air cooled argon and .02% with water cooled argon
lasers
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