Wide Bandwidth Wavelength combination for 50G-PON through adiabatic 3-dB coupler based on asymmetric MZI

Photonic integrated wavelength combination through an asymmetric Mach-Zehnder interferometer was proposed. It contains an adiabatic 2×2 coupler and a multi-mode interference splitter, which enables the input of 1342 and 1490 nm to couple into one output port. The transmission efficiency of the wavelength combining is more than 90% at the wavelength of 1342–1577 nm. The wavelength beam combination scheme proposed above is an attractive candidate for 50G-PON wavelength division multiplexing based on the TFLN photonic integration platform.