Abstract: An integrated optical transceiver apparatus and an OLT are provided. A first splitter and a second splitter are integrated into a PLC structure of the apparatus. The first splitter is configured to output signal light of a first wavelength and signal light of a second wavelength, and output signal light of a third wavelength and signal light of a fourth wavelength. The second splitter is configured to separate the signal light of the third wavelength and the signal light of the fourth wavelength, output the signal light of the third wavelength, and output the signal light of the fourth wavelength. A first optical detector and a second optical detector are disposed on the PLC structure, where the first optical detector and the second optical detector are configured to convert, into electrical signals, the signal light output by the second splitter and the signal light output by the second splitter.

Abstract: A optical chip includes: an optical splitter, configured to receive a first electromagnetic wave signal, and divide the first electromagnetic wave signal into two electromagnetic wave signals for output; and a first interferometer and a second interferometer, where the optical splitter, the first interferometer, and the second interferometer are sequentially coupled, and the first interferometer and the second interferometer are configured to receive one of the two electromagnetic wave signals, so that the one electromagnetic wave signal is interfered twice, to output a plurality of second electromagnetic wave signals. The other one of the two electromagnetic wave signals is output as a third electromagnetic wave signal, and the second electromagnetic wave signal and the third electromagnetic wave signal may be used to obtain wavelength information of the first electromagnetic wave signal through optical-electrical conversion. A wavelength measurement system is further provided.