Integrated polarization multiplexing IQ modulator based on lithium niobate thin film and all waveguide structure

The integrated polarization multiplexing in-phase and quadrature (IQ) modulator based on lithium niobate (LN) thin film and all waveguide structure is designed. It consists of polarization demultiplexer (PDM), polarization multiplexer (PM) and two IQ modualtors (IQM). Each of IQM contains two different couplers and two Mach-Zehnder modulators (MZM). The theory of multimode interference (MMI) is used to design the PDM, PM and IQM. For PDM and PM, the extinction ratios of TE and TM polarized lights reach 23 dB and 21 dB. Quadrature Phase Shift Keying (QPSK) and 16 quadrature amplitude modulation (16-QAM) are achieved well with the integrated modulator.