Abstract:Lithium niobate Mach-Zehnder modulator（MZ-LN）is one kind of waveguide-type optical modulators commonly used in optical communication. Based on introducing the principles and structure of MZ-LN, the performance curve of modulation, the half-wave voltage and the zero-point-voltage were measured. Experimental results demonstrate that the curve of half-wave voltage has offset voltage and the zero-point will drift during working. It was experimentally studied the impact of zero-point-drift on the NRZ code and DPSK signal. And it is indicated that one reason for zero-point-drift is the stored charge effects caused by the internal structure of modulator.
