power of 1.8 dBm was measured in the transmitter at an injection current of 50 mA. Based on the BPM simulation, the overall optical coupling loss of the transmitter part is 8.4 dB, which includes an LD-PLC coupling loss of 6.0 dB, a filter loss of 1.4 dB, and a PLC-fiber coupling loss of 1.0 dB. When compared with the measured output power of 11.6 dBm, this result indicates that the alignment accuracy after bonding was excellently achieved with an excess loss of 1.4 dB. Besides, the measured responsivity of PD is 0.52 A/W with the estimated coupling loss of 2.8 dB, which also includes a fiber-PLC coupling loss of 0.4 dB, a filter loss of 0.6 dB, and an excess loss of 1.8 dB. Figure 6 shows the measured bit error rate (BER) of the bidirectional transceivers using a 1.25-Gb/s pseudorandom bit sequence (PRBS) of 2 7 Ϫ 1 data. The transceiver exhibits a minimum sensitivity of less than Ϫ26.5 dBm at a BER of 10 Ϫ12 during an output power of 0 dBm in transmitter. These results indicate that this module is suitable for PON applications.
4. CONCLUSION
We have presented a FP-LD hybrid packaging scheme for a 1.25-Gb/s bidirectional transceiver. The filter-integrated PLC platform and PD insertion method were introduced in order to eliminate the unstable multiple flip-chip bonding process, and include only single-bonding of the FP-LD simplified packaging process for a low-cost transceiver. The measured performance exhibited a sensitivity of Ϫ26.5 dBm during full-duplex operation. The result successfully satisfied the criteria required by E-PON. Therefore, the proposed packaging scheme including integrated filter can be effectively used for a low-cost compact transceiver.