Highly sensitive 565 Mb/s DPSK heterodyne transmission experiment using direct current modulation of a DFB laser transmitter

• Published in: IEEE photonics technology letters Vol. 3; no. 9; pp. 838 - 841
• Main Authors: Clesca, B., Chesnoy, J., Biotteau, B., Jacquinot, J.C., Accard, A., Bissessur, H., Fernier, B., Lemaire, V.
• Format: Journal Article
• Language: English
• Published: IEEE 01-09-1991
• Subjects: Biomedical optical imaging; Differential quadrature phase shift keying; Distributed feedback devices; Intensity modulation; Optical feedback; Optical mixing; Optical pulses; Optical sensors; Optical transmitters; Phase modulation
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/68.84511

A comparison between external phase modulation and phase modulation obtained through direct current modulation of a multiquantum-well distributed feedback (DFB) transmitter is reported for a sensitive 565 Mb/s differential-phase-shift-keying (DPSK) heterodyne transmission experiment. A limited sensitivity penalty for direct phase modulation is expected from the driving current pulse shape, the transmitter FM response and the receiver characteristics. The experimentally observed 0.5 dB penalty is in agreement with theory and highlights the potential of direct DPSK modulation as compared to both standard DPSK and continuous-phase frequency shift keying (CPFSK) schemes.< >