A passive optical network (PON) is a fiber-optic telecommunications network that uses only unpowered devices to carry signals, as opposed to electronic equipment. In practice, PONs are typically used for the last mile between Internet service providers (ISP) and their customers. This network is suitable for building. This paper builds a high-bit rate dual polarization (DP) QPSK and 16-QAM modulation formats coherent optical transmission system for Passive Optical Networks (PON). Higher-order modulation formats could be used to provide huge data capacity, extended coverage, and long-reach connections. They're called “passive” because they don't require any electrical power to distribute the signal once it's sent across.