Simultaneous Prescaled Clock Recovery and Serial-to-Parallel Conversion of Data Signals Using a Polarization Modulator-Based Optoelectronic Oscillator

This paper demonstrates a new type of an optoelectronic oscillator (OEO) that employs a polarization modulator (PolM) for realizing prescaled optical clock recovery and 1 : 2 serial-to-parallel conversion of optical data signals. By injecting the 40-Gb/s return-to-zero data signals along with the continuous-wave light, the PolM-OEO generates the 20-GHz clock and two 20-Gb/s data streams simultaneously. The OEO is based on the concept of the regenerative frequency divider, which ensures stable injection-locked operation at 20 GHz even in the absence of subharmonic tones in the input signal. The PolM-OEO is applicable to all-optical modulation format conversion from on-off keying to quadrature phase shift keying by combining it with a cross-phase modulation-based wavelength converter.