| 摘要 |
PURPOSE:To attain communication with a wide transmission band and high S/N by applying intensity modulation to a transmission optical signal which is generated by direct modulation or the like of a semiconductor laser or the like and simultaneously acompanied with the variance of signal in wavelength and performing the signal processing in a reception part in accordance with the wavelength so that the degree of a relative ratio of intensity modulation of a multilevel signal is emphasized. CONSTITUTION:This system consists of a transmitter 1, an optical fiber 2, a wavelength selecting element 3 as the Fabry-Perot wavelength selective signal processing means, and a receiver 4. Modulation with time of a transmission optical output PT and a wavelength lambda is shown in the figure, and the intensity modulation of on/off is applied as well as the output wavelength for turning-on and that for turning-off are modulated. The binary signal subjected to intensity modulation and its wavelength is modulated is sent from the transmitter 1 having a light source means. Thus, S/N is improved to extend the transmission band even if the laser value direct modulation system or the like is adopted. |
