Integrated optical transceiver apparatus and optical line terminal

An optical line terminal comprising a plurality of optical modules, wherein any one of the plurality of optical modules comprises an integrated optical transceiver apparatus, wherein the integrated optical transceiver apparatus comprises:

• a planar lightwave circuit structure, wherein:
• an optical device is integrated in the planar lightwave circuit structure, and the optical device comprises a first splitter and a second splitter;
• the first splitter has a first end, a second end, and a third end, and the first splitter is configured to output, from the second end of the first splitter to an optical fiber, a signal light of a first wavelength and a signal light of a second wavelength that are received by the first end of the first splitter, and output, from the third end of the first splitter, a signal light of a third wavelength and a signal light of a fourth wavelength that are received by the second end of the first splitter from the optical fiber;
• and
• the second splitter has a first end, a second end, and a third end, the first end of the second splitter is connected to the third end of the first splitter, and the second splitter is configured to separate the signal light of the third wavelength and the signal light of the fourth wavelength that are output from the third end of the first splitter, and output the signal light of the third wavelength from the second end of the second splitter and output the signal light of the fourth wavelength from the third end of the second splitter;
• and
• an electrical device located on the planar lightwave circuit structure, the electrical device comprises a first optical detector and a second optical detector, the first optical detector is configured to convert, into an electrical signal, the signal light of the third wavelength that is output by the second end of the second splitter, and the second optical detector is configured to convert, into an electrical signal, the signal light of the fourth wavelength that is output by the third end of the second splitter, wherein
• the planar lightwave circuit structure has a top surface and a side surface, the side surface surrounds the top surface, the first optical detector and the second optical detector are located on the side surface or the top surface, and an end surface of the optical fiber is disposed opposite to the side surface.