Low-Chirp 85-Gb/s Duobinary Modulator in InP Using Electroabsorption Modulators

• Published in: IEEE photonics technology letters Vol. 21; no. 17; pp. 1199 - 1201
• Main Authors: Doerr, C.R., Raybon, G., Liming Zhang, Buhl, L.L., Adamiecki, A.L., Sinsky, J.H., Sauer, N.J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplitude modulation; Bandwidth; Chirp; electroabsorption; Indium phosphide; Indium phosphides; Integrated circuit packaging; Integrated circuits; Integrated optics; Mach-Zehnder interferometers; Modulators; optical duobinary; Optical interferometry; Optical modulation; Phase modulation; Phase shift keying; Phase transformations; Photonic integrated circuits; Photonics; quantum confined Stark effect
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2009.2024165

In 2005, Griffin showed that an InP phase-shift-keying/duobinary Mach-Zehnder interferometer (MZI) modulator could achieve good transmission performance at 10 Gb/s, despite modest residual amplitude modulation in the phase modulators in the MZI (ratio of real to imaginary part of index change was ~0.1). Here we show that even strong amplitude modulation in the ldquophaserdquo modulators (ratio of real to imaginary part of index change is ~1.0) gives good transmission performance. Allowing for strong amplitude modulation allows a significant increase in modulator bandwidth. We demonstrate low-chirp 85.4-Gb/s optical duobinary generation in a fully packaged InP photonic integrated circuit.