Abstract: In order to provide an optical module capable of detecting a frequency variation at higher accuracy, an optical module includes a light source that outputs light, a first splitter that splits the light, a band filter that transmits one piece of light split by the first splitter with a periodic frequency characteristic, a transmitted-light detector that detects transmitted-light intensity transmitted through the band filter, a variation device that varies the transmitted-light intensity in a first direction, by varying a parameter of a signal being input to the light source, and a frequency variation detection device that detects a frequency variation of the light from the light source, when a variation of the transmitted-light intensity in a second direction being opposite to the first direction is detected, in a case where the variation device varies the parameter from the first value to the second value.

Abstract: Please delete the Abstract of the Disclosure, and replace it with the following: A wavelength variable optical transmitting unit is configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel for the first channel setting optical signal. A wavelength variable optical receiving unit is configured to, when the optical transceiver receives a second channel setting optical signal from another optical transceiver, transfer second channel information contained in the second channel setting optical signal and indicating a channel for the second channel setting optical signal. A control unit is configured to control the wavelength variable optical transmitting unit and the wavelength variable optical receiving unit.

Abstract: An optical reception device according to an exemplary aspect of the invention includes an optical front-end means for demodulating an inputted optical signal, converting the demodulated signal into an electrical signal and outputting the electrical signal, a pre-emphasis means for adding a high frequency component to the electrical signal, a digital signal processing means for receiving input of the electrical signal with the high frequency component added thereto via a transmission wire, and for performing a digital coherent reception process on the inputted electrical signal, an error detection means for detecting a signal error in the digital coherent reception process and a feedback control means for varying the level of a high frequency component added at the pre-emphasis means and, in accordance with signal errors detected at that time, controlling the pre-emphasis means.

Abstract: An optical reception device according to an exemplary aspect of the invention includes an optical front-end means for demodulating an inputted optical signal, converting the demodulated signal into an electrical signal and outputting the electrical signal, a pre-emphasis means for adding a high frequency component to the electrical signal, a digital signal processing means for receiving input of the electrical signal with the high frequency component added thereto via a transmission wire, and for performing a digital coherent reception process on the inputted electrical signal, an error detection means for detecting a signal error in the digital coherent reception process and a feedback control means for varying the level of a high frequency component added at the pre-emphasis means and, in accordance with signal errors detected at that time, controlling the pre-emphasis means.