All-Optical OOK to Multiple-Level PSK Format Conversion Using a Self-Generating Optical Clock

We have demonstrated all-optical format conversion from ON-OFF-keying to multiple-level phase-shift-keying based on self-generating optical clock scheme. This scheme enables us to generate an optical clock synchronized with an input data signal without a clock recovery circuit and an optical pulse source. In this letter, we have evaluated and compared the format conversion performances using a conventional optical clock and the self-generating optical clock in terms of bit-error-rate measurement. As a result, we have successfully achieved the low power penalty to the conventional scheme of <;0.3 dB.