| 摘要 |
PURPOSE:To realize light frequency modulation without using direct modulation of a light source by switching light from >=2 light sources of different oscillation wavelength conforming to information signals, and sending out different wavelength for each information. CONSTITUTION:Light emitted from the first light source 1 and the second light source 2 is led respectively to input ports A and B of a light switch 5 by the first single polarization fiber 3 and the second single polarization fiber 4. Voltage impressed to the light switch is controlled by a signal generator 6. Thereby, the port A input is emitted from a port C, and the port B input is emitted from the port C at the time of transmitting a mark signal, and the port A input is emitted from the port D and the port B input is emitted from the port C at the time of transmitting a space signal. Accordingly, the output of the port C and port D differs in frequency according to information signals and the frequency shift keying (FSK) is performed. |
