| 摘要 |
<p>In a control signal transmission method for an optical transmission system, a control signal having a high signal to noise ratio is transmitted without providing any deterioration in characteristic to the information signal. Upon transmission of a control signal of the optical transmission system, an optical signal modulated (4) with an information signal (2) is polarization modulated (7) with the control signal (51), and the polarization state of the polarization modulated polarization modulation optical signal is varied (9) with a related control signal (52) to obtain a modulated optical signal, and the control signal is transmitted with the modulated optical signal. In a corresponding control signal reception method for an optical transmission system, a modulated optical signal thus produced is received, and the polarization modulated control signal is extracted by means of a polarizer (17), the output of which is converted (19) into an electric signal, and a control signal generated by circuitry including a bandpass filter (20). <IMAGE></p> |
