A Clock Enhanced Loop for Simultaneous Error-Free Demultiplexing and Clock Recovery of 160Gb/s OTDM Signal Single-Channel Transmission over 100km

A simple clock enhanced loop of cascaded electro-absorption modulators （EAMs） and 10 GHz clock recovery modules is presented. The intensity of harmonic of clock-frequency component is analyzed theoretically and verified experimentally in a 160 Gb/s OTDM 100 km transmission system. The 10 GHz clock component is enhanced obviously before launching into the clock recovery module and the recovered clock signal exhibits low rms jitter of 〈400 fs. Moreover, completely error^-1free （10-12） transmission is observed for more than two hours without using forward error correction technology. The power penalty is about 3.6 dB. The proposed loop has merits of enhancing base clock component, simultaneously de-multiplexing and clock recovery, which make the performance of this loop more stable and high suppression of non-target channels.

A Simple Loop for Simultaneous OTDM Demultiplexing and Clock Recovery

A simple and stable loop consisting of a pair of concatenated electroabsorption modulators （EAMs） and 10 GHz clock recovery module is presented and demonstrated experimentally for simultaneous demultiplexing and clock recovery for OTDM networks. The 10 Gb/s demultiplexed signal and 10 GHz recovered clock are successfully implemented from 80 Gbit/s and 160 Gbit/s OTDM signals utilizing the loop. The loop based on EAM-PLL can provide excellent tolerance range （〉 5 dB） of the OSCR of the source laser, and the recovered clock signal exhibits low rms jitter over a dynamic input optical power range of 15 dB.

Multi-wavelength fiber ring laser based on semiconductor optical amplifier and sampled fiber Bragg grating in a Sagnac loop interferometer

Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.

40-to-10-Gb/s demultiplexing using an electro-absorption sampling window

The demultiplexing experiment from a 40 Gb/s optical time-division multiplexing signal is completed by using electro- absorption sampling window based on electronic phase-locked loop circuit for clock recovery. Error-free demultiplexing is achieved when the launched optical power into electro-absorption sampling window reaches 5.5 dBm without optical filter following the EDFA.