Analysis and testing of total ionizing dose effect on several commercial optical transceivers via gamma-ray radiation

In our Letter, we selected several commercial optical transceivers, which consist of single-channel transceiver modules, parallel transmitting and receiving modules, and Ethernet passive optical network(EPON) optical line terminal(OLT) and optical network unit(ONU) modules, to do the total ionizing dose(TID) testing via the gamma-ray radiation method. The changing of current and receiver sensitivity of optical transceivers is discussed and analyzed. Based on the TID testing exposed to a TID of 50 krad(Si) at a dose rate of about 0.1 rad(Si)/s,the performance of single-channel transceivers and parallel receiving modules has not changed after 50 krad(Si)exposure, the parallel transmitting and EPON ONU modules have not worked after 40 krad(Si) and 47 krad(Si)exposure, the EPON OLT module has bit error in the process of irradiation, and it can work well after annealing;the reason for the error of OLT is analyzed. Finally, based on the theoretical analysis and testing results, this Letter provides several design suggestions to improve the reliability for optical transceivers, which can be referenced by satellite system designation for various space missions.     

All-optical format conversion of NRZ-OOK to QPSK and 16QAM signals via XPM in a SOA-MZI

This letter proposes a scheme for the format conversion of on-off keying (OOK) signal to quadrature phase-shift keying (QPSK) and 16-ary quadrature amplitude modulation (16QAM) signals via cross-phase modulation (XPM) in a semiconductor optical amplifier (SOA). Theoretical and experimental analyses of the format conversion scheme are conducted to validate its feasibility. The phase changing is obtained because of the XPM in the SOA. The QPSK and 16QAM signals are converted from the OOK signal. The performance of the 10 Gb/s format conversion system is evaluated and discussed. The receiver sensitivities of the converted QPSK and 16QAM signals after detection are -27.25 and -23.5 dBm, respectively, at a bit error rate (BER) of 109 .     

Experimental and theoretical analyses of RSOA-based colorless-ONUs with 4PAM signal in the up-link

A scheme that utilizes the 4-level pulse-amplitude-modulated (4PAM) signal as the re-modulated signal of colorless optical network units (ONUs) based on reflection semiconductor optical amplifiers (RSOAs) is proposed. The system with 10-Gb/s non-return-to-zero (NRZ) downstream and 5-Gb/s 4PAM upstream signals is theoretically analyzed and experimentally verified. Simulation and experimental results reveal that the 4PAM re-modulated signal yields better performance than the NRZ signal in the upstream. A receiver power penalty of 1.6 dB is also improved by the 4PAM signal at back-to-back (BtB) transmission, whereas another receiver power penalty of 1.5 dB improved after 30-km single mode fiber transmission, where 4PAM signals are used as upstream signal.