A method for generation of optical FM signal through injection locking

This paper proposes a scheme for the generation of optical frequency modulation (FM) signals through direct modulation and injection locking of semiconductor lasers. The method is simple and effective. The amplitude modulation of the AM-FM optical carrier generated through direct modulation can be drastically reduced by an injection-locked semiconductor laser. For this purpose, the AM limiting property of the injection-locked semiconductor laser has been investigated theoretically in detail. The FM index and the second harmonic distortion of the resulting FM signal at the output of the AM limiter has also been calculated