| 摘要 |
PURPOSE:To attain relaying for transmission by applying phase modulation to an ultrahigh speed optical phase modulation optical wave by means of an optical carrier outputted from a ligh source whose frequency is superhighly stable, having high Q, single polarized wave and single mode, of the same characteristic as that for carrier phase-modulated at the transmission side and transmitting the result to an optical fiber transmission line. CONSTITUTION:An optical wave Somega transmitted from an optical fiber 1 is extracted by a Y circulator 8, led to a photodetector array 12 via a spatial coupling filer 11 having a transfer function Yomega=Somega of received light having a conjugate characteristic with the optical wave Somega, a Y circulator 9 and a lens 10, the demodulation is conducted in parallel processing, the signal is impressed to a waveguide 22 comprising an LD having a low Q which is adjusted to be on the verge of emission as an electric signal so as to irradiate a light having a center frequency of omega2, the light is superimposed on an optical fiber 5 as a phase modulation wave by an optical carrier having a center frequency omega1 outputted from an LD14 having a high Q, and the result is transmitted to an optical fiber 2 via the Y circulators 8, 9 . The optical wave from the LD13 having low Q and the LD14 having high Q and superimposed on the optical fiber 5 is phase- modulated on the optical fibers 5, 3 and 2, and the transmitted ultrahigh speed optical phase modulation optical wave is reproduced. |
