Fig. 1. Experimental setup.

Fig. 2. Frequency response of 10 G-class EML and PIN at BtB.

Fig. 3. Receiver performance of 25 Gb/s PAM-4 with and without ASE filter and 10 Gb/s NRZ with ASE filter.

Fig. 4. Upstream 25 Gb/s PAM-4 signal BER measurement with different positive (left) and negative (right) dispersion values in the BtB case.

Fig. 5. Upstream 25 Gb/s PAM-4 signal BtB sensitivity variations with dispersion.

Fig. 6. Eye diagrams of 25 Gb/s PAM-4 signal with and without −500  ps/nm dispersion compensation in BtB, 20, and 40 km fiber transmission cases.

Fig. 7. BER curves of 25 Gb/s PAM-4 signal in BtB, 20, 40 km fiber transmission cases.

Fig. 8. Receiver performances of 25 Gb/s EDB signal with and without ASE filter and 10 Gb/s NRZ with ASE filter.

Fig. 9. Upstream 25 Gb/s EDB signal BER measurement with different positive (left) and negative (right) dispersion values in the BtB case.

Fig. 10. Upstream 25 Gb/s EDB signal BtB sensitivity variations with dispersion.

Fig. 11. Eye diagrams of 25 Gb/s EDB signal with and without −600  ps/nm dispersion compensation in the BtB, 20, and 40 km fiber transmission cases.

Fig. 12. BER curves of 25 Gb/s EDB signal in the BtB, 20, and 40 km fiber transmission cases.

Fig. 13. Upstream burst-mode timing sequences at (a) 1000 and (b) 100 ns/div.