All-Optical Clock Recovery of 20 Gbit/s NRZ-DPSK Signals Using Polarization-Maintaining Fiber Loop Mirror Filter and Semiconductor Optical Amplifier Fiber Ring Laser
Source: Reed Elsevier
Ultra-Dense Wavelength Division Multiplexing (UDWDM) concept originates in long-haul fiber-optic communications, it is also expected to be a key enabling technology for future massively parallel computing systems. As fiber-optic transmission systems approach 10 Tbit/s capacity, the utility of employing simple NRZ or RZ modulation is questionable. Therefore, more sophisticated modulation formats are developed to increase spectral efficiency, and improve tolerance to fiber nonlinearity induced distortion. One of the interesting candidates is Differential Phase-Shift Keying (DPSK). All-optical Clock Recovery (CR) is a vital ingredient for many key functions such as 3R regeneration, all-optical demultiplexer, and so on.