An optical gas identification system including a measuring cell (20), a
modulated light source (10), a microphone (22), and a signal amplifier
(30). The light source (10) comprises a plurality of laser diodes (12)
and can selectively illuminate the modulated light with specific
wavelengths. The gas identification system can determine the object
signal by use of the signal processor (70) and the database (60) with the
various signal patterns.