Symmetric Mach-Zehnder-type all-optical switches and ultrafast all-optical signal processing.

Symmetric Mach-Zehnder (SMZ) type all-optical switches, namely, the SMZ, polarization-discriminating SMZ (PD-SMZ), and delayed interference signal wavelength converter (DISC), are described in detail. All of these all-optical switches are characterized by push–pull operation and allow ultrafast switching not limited by the relaxation time of high-efficiency nonlinear optical materials that are suitable for low-power operations. They make possible a low-chirp switching window of a quasi-square type that is important in practice. Ultrafast all-optical signal processing with an SMZ, namely, 168 → 10.5 Gbit/s error-free DEMUX (using a hybrid-integrated SMZ, HI-SMZ), zero-penalty optical signal pulse regeneration at 84 and 168 Gbit/s, and error-free all-optical wavelength conversion are reported. In experiments with pulse regeneration and wavelength conversion, the error rate is evaluated after DEMUX to 10.5 Gbit/s by HI-SMZ because the signal light after signal processing has ultrahigh speed. © 2002 Scripta Technica, Electron Comm Jpn Pt 2, 85(2): 1–17, 2002 [ABSTRACT FROM AUTHOR]