Intensity modulation technique using a directly frequency-modulated semiconductor laser and an interferometer

Harmonic distortion in semiconductor laser direct frequency modulation is described with the aid of a nonlinear differential equation for the photon density including gain damping. Curves are presented showing the fundamental, second-order harmonic and third-order harmonic FM responses. It is found that systems using a frequency-modulated laser and an interferometer would exhibit lower distortion levels than those using direct intensity modulation of the laser diode.<
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