基于信号频谱变换的原理，利用微环谐振器的梳状谱传输特性，辅助以窄带滤波器，将全光归零(RZ)码信号的频谱包络转变为较理想的非归零(NRZ)码信号的频谱包络，从而实现RZ 码到NRZ 码的码型转换。详细研究了转换后的NRZ 信号眼图质量与设备因素，如窄带滤波器的选择、微环谐振器的耦合条件以及输入信号RZ 码占空比的关系。结果表明窄带滤波器为2 阶巴特沃斯滤波器时，微环谐振器的耦合条件以及RZ 码占空比对码型转换效果的影响较小。另外，通过调整微环谐振器的尺寸，设计的码型转换器能与不同速率的系统相兼容，能更好地适应未来光网络的发展。

Based on signal spectral transforming principle, an all-optical return-to-zero (RZ) to non-return-tozero (NRZ) format conversion is realized by using a micro-ring resonator with the comb transmission spectrum and a narrow bandpass filter. Influences of devices′ parameters, such as different narrow bandpass filters, coupling conditions of micro-ring resonator and duty ratio of the RZ input signal, on eye-diagram quality of converted NRZ signal are investigated in detail. Results demonstrate that 2-order Butterworth filter is expected to decrease the influences of coupling conditions and the duty ratio of RZ signal on the conversion performances. In addition, by adjusting the ring-resonator size, the designed RZ-to-NRZ format converter is compatible with system having several bit rates signals. This will be better adapt to the development of future optical networks.<网络出版日期.2015-01-09