A theoretical model for all-optical modulation format conversion from amplitude-shift keying (ASK) to phase-shift keying (PSK) has been proposed using a reflective vertical cavity semiconductor saturable absorber (R-VCSSA). The R-VCSSA is a nonlinear device. The phase response of the device has been studied numerically with different input intensities. It has been observed from the simulated result that a maximum phase of ${{\pm}}\pi /{{2}}$ with the reflected signal could be obtained by properly adjusting the input intensity. The conversion of an intensity-modulated return-to-zero (RZ) signal to a binary phase-shift keying signal has been analyzed based upon the simulated result. The pump signal is considered to be an intensity-modulated RZ signal with wavelength fixed at the cavity resonance of the R-VCSSA device, and a cavity-detuned continuous-wave source is used as a probe signal to carry out this operation. This device could be employed in all-optical future networks as an all-optical nonlinear signal converter for ASK to PSK conversion.

中文翻译：

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使用垂直腔量子阱吸收器对从振幅键控到相移键控的全光调制格式转换建模

已经提出了使用反射垂直腔半导体可饱和吸收体（R-VCSSA）进行从幅度键控（ASK）到相移键控（PSK）的全光调制格式转换的理论模型。R-VCSSA是非线性设备。已经用不同的输入强度对设备的相位响应进行了数值研究。从模拟结果可以看出，最大相位为$ {{\ pm}} \ pi / {{2}} $通过适当调节输入强度可以得到反射信号。基于模拟结果，已经分析了强度调制的归零（RZ）信号到二进制相移键控信号的转换。泵浦信号被认为是强度固定的RZ信号，其波长固定在R-VCSSA器件的谐振腔，并且谐振腔失谐的连续波源用作探测信号来执行此操作。该器件可以在全光未来网络中用作ASK到PSK转换的全光非线性信号转换器。