| 摘要 |
PURPOSE:To obtain the analog optical transmitter having an excellent distortion characteristic by selecting an oscillated wavelength of a signal semiconductor laser shorter than a gain peak wavelength of an optical fiber amplifier and specifying the phase difference of a distortion component. CONSTITUTION:The transmitter consists of a signal semiconductor laser 1, an optical fiber amplifier 2, a dispersion shift fiber 3 and a light receiving device 4. Then the signal light radiating from the laser 1 has a relation of ¦(OIMk+OFMj+OIMj+OFMk)/2-OKj¦<pi/2, where OIMk, OIMj are respectively phases of an intensity modulation(IM) components at modulation frequencies fk, fj and Okj is a phase of a quadratic intermodulation distortion component, and the oscillated wavelength is selected shorter than a gain peak wavelength of the optical fiber amplifier 2. Thus, the transmission distortion caused when the radiation light from the laser 1 modulated by an analog signal is amplified by the amplifier 2 is reduced in this way and analog optical transmission with low distortion is realized. |
