Optical signal transmission apparatus and optical transmission system

A system, comprising:

• a first optical module configured to send a first combined optical signal, wherein the first combined optical signal is an optical signal combining an optical signal of a first wavelength and an optical signal of a second wavelength;
• a second optical module;
• and
• an optical signal transmission apparatus, wherein the optical signal transmission apparatus comprises:
• a first fiber collimator configured to receive the first combined optical signal from the first optical module;
• a second fiber collimator configured to input an optical signal of a third wavelength;
• a third fiber collimator;
• a first filter and a second filter;
• and
• a first beam splitter configured to:
• receive the first combined optical signal from the first fiber collimator;
• split the first combined optical signal from the first fiber collimator into the optical signal of the first wavelength and the optical signal of the second wavelength;
• transmit the optical signal of the first wavelength to the first filter, wherein the first filter is configured to transmit the optical signal of the first wavelength to the third fiber collimator;
• and
• transmit the optical signal of the second wavelength to the third fiber collimator through the first filter and the second filter;
• wherein the second optical module is configured to send an optical signal of a third wavelength to the second fiber collimator;
• wherein the second filter is configured to transmit the optical signal of the third wavelength from the second fiber collimator to the third fiber collimator;
• and
• wherein the third fiber collimator is configured to output a second combined optical signal, wherein the second combined optical signal is an optical signal combining the optical signal of the first wavelength, the optical signal of the second wavelength, and the optical signal of the third wavelength.