Abstract: An optical transceiver, for receiving an optical signal on which a monitor signal is superimposed, includes: an extractor configured to extract the monitor signal from the optical signal received; and a reception processor configured to reproduce a monitor data from the monitor signal extracted by the extractor.

Abstract: An optical transceiver includes an optical transmitter transmit an optical signal; an optical receiver to extract a monitoring control signal from an optical signal, the monitoring control signal including first and second frames having the respective headers, and being separated in time; and a processing part to generate a bit stream from the monitoring control signal; generate a first byte stream from the bit stream; extract monitoring control data from a byte stream subsequent to the first byte stream, if the first byte stream is equal to the first header; generate a second byte stream from the bit stream if the first byte stream is different from the first header, the second byte stream having the same length as the second header; and extract the monitoring control data from a byte stream subsequent to the second byte stream if the second byte stream is equal to the second header.

Abstract: An optical transceiver, for receiving an optical signal on which a monitor signal is superimposed, includes: an extractor configured to extract the monitor signal from the optical signal received; and a reception processor configured to reproduce a monitor data from the monitor signal extracted by the extractor.

Abstract: An optical transmitter is disclosed, where the optical transmitter shows an emission wavelength kept stable in one of grid wavelengths of the WDM system during the boot of the transmitter. The optical transmitter includes an LD, a TEC to control a temperature of the LD, and a controller. Detecting the flag to enable the optical output, the controller increases the driving current of the LD concurrently with the decrease of the temperature of the TEC to compensate the self-heating of the LD due to the driving current.

Abstract: An optical transmitter is disclosed, where the optical transmitter shows an emission wavelength kept stable in one of grid wavelengths of the WDM system during the boot of the transmitter. The optical transmitter includes an LD, a TEC to control a temperature of the LD, and a controller. Detecting the flag to enable the optical output, the controller increases the driving current of the LD concurrently with the decrease of the temperature of the TEC to compensate the self-heating of the LD due to the driving current.

Abstract: An optical transmitter implemented with an LD whose temperature is stably controlled is disclosed. A temperature of the LD is continuously monitored; and a difference from the target temperature and a time derivative thereof are calculated. When the time derivative becomes substantially zero, that is, the difference becomes an extremum, the convergent range for the time derivative is changed depending on the extremum, or an average of the current extremum and the previous extremum.