| 摘要 |
A method of controlling the depth of modulation of an optical source 14 in a frequency shift keyed intensity modulation optical transmitter, the method including the steps of impressing on a digitally modulated drive signal for the source an amplitude modulation at a frequency less than that of the digital signal, detecting at 24 the envelope of the transmitted signal, multiplying the detected envelope signal with the impressed frequency and deriving therefrom a control signal to control the depth of modulation of the source. <IMAGE> |
