부산대학교 도서관

An optical transmitter apparatus capable of a transmission rate of at least 100 gbit/second comprises at least three input transmitters that each provide at an output an NRZ optical signal, at least two of the NRZ optical signals having substantially the same bit rate, each of the signals having a bit rate which is less than 100 Gbit/s and the sum of the bit rates of all of the at least three transmitters being at least equal to 100 Gbit/s, an NRZ to RZ converter associated with each transmitter which converts each NRZ signal into an optical RZ signal with the signal remaining in the optical domain during conversion, the optical RZ signal having the same bit rate as the corresponding NRZ signal, an optical time division multiplexer which converts the RZ signals into at least two further signals, one of the further signals being formed by bitwise interleaving the bits of the at least two of the RZ signals which have the same bit rate, and a polarisation multiplexer which processes the two further signals to provide two output signals of differing polarisation, each of the two output signals having the same bit rate as a respective one of the two further signals. The NRZ to RZ converters may be implemented using a SOA based device.