US Patent 9768907 Optical transmission apparatus and wavelength calibration method

An optical transmission apparatus, includes: a reference-wavelength light source configured to generate reference light; a reference wavemeter configured to be calibrated by using the reference light; a receiver configured to receive measurement light transmitted from another optical transmission apparatus and wavelength information about the measurement light; and a controller, wherein the controller configured to: detect error between a first wavelength of the measurement light detected by using the reference wavemeter, and a second wavelength included in the wavelength information; and send error information that represents the error to the another optical transmission apparatus.