周期极化反转铌酸锂(PPLN)光波导以其响应速度超快和无自发辐射噪声影响等独特优点在高速全光信号处理中表现出优越性能并获得广泛应用。传统上主要利用PPLN光波导对比特速率和调制格式透明的特性实现全光波长转换、全光逻辑门和全光码型转换等功能。我们发现PPLN光波导其实也存在其不透明的一面。当携带相位信息的信号光置于PPLN光波导准相位匹配(QPM)波长处 Periodic Polarization Reversal Lithium niobate (PPLN) optical waveguides show superior performance and are widely used in high speed all-optical signal processing due to their unique advantages of fast response and no spontaneous emission noise. The traditional use of PPLN optical waveguide on the bit rate and modulation format transparent features to achieve all-optical wavelength conversion, all-optical logic gate and all-optical code conversion and other functions. We found that PPLN optical waveguide actually has its opaque side. When the signal light carrying the phase information is placed at the PPLN optical waveguide quasi phase matching (QPM) wavelength