Title :
Influence of amplitude modulation induced by LD direct modulation on FM signal transmission
Author :
Yoshida, Seiji ; Iwshita, K.
Author_Institution :
NTT Transmission Syst. Lab., Kanagawa, Japan
Abstract :
Transmission characteristics of sinusoidally frequency/phase modulated signals near the zero-dispersion wavelength are investigated. It is shown that waveform distortion is suppressed by transmission at a little longer wavelength than zero-dispersion wavelength for an LD direct modulated signal. This is because the amplitude modulation component induced by LD direct modulation is canceled by waveform distortion resulting from FM-AM conversion. This cancellation occurs most effectively when the phase difference between AM and FM of LD direct modulation is pi /2, which is expected for high-speed modulation. Since waveform distortion is less in the case of a wide frequency range, waveform distortion for an NRZ signal is also considered to be suppressed by transmission at a little longer wavelength than zero-dispersion wavelength.<>
Keywords :
amplitude modulation; frequency modulation; light emitting devices; optical communication equipment; optical links; optical modulation; FM signal transmission; FM-AM conversion; LD direct modulation; NRZ signal; amplitude modulation; high-speed modulation; light diode; nonreturn-to-zero; phase difference; sinusoidally frequency/phase modulated signals; waveform distortion; wide frequency range; zero-dispersion wavelength; Amplitude modulation; Chirp modulation; Chromatic dispersion; Degradation; Frequency estimation; Frequency modulation; Frequency shift keying; Optical modulation; Optical receivers; Phase modulation;
Journal_Title :
Photonics Technology Letters, IEEE
