Authors:
Siti Sulikhah
1
;
San-Liang Lee
1
and
Hen-Wai Tsao
2
Affiliations:
1
Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
;
2
Department of Electrical Engineering, National Taiwan University, Taipei 10607, Taiwan
Keyword(s):
Electro-absorption Modulator, Optical Interconnect, Partial Grating, Quarter-Wave-Shifted, Uniform Grating.
Abstract:
High-speed electro-absorption modulated lasers (EMLs) with three DFB laser structures (uniform grating (UG), asymmetric quarter-wave-shifted (QWS), and partially corrugated grating (PCG)) are investigated here under 56-Gb/s NRZ signal modulation. It is known that the former UG-EML suffers from performance degradation due to the residual facet reflection (RFR) and facet phase fluctuation. PCG-EML with 300-µm long laser section, 175-µm long grating section, 100-µm long modulator section, and 10-3 front-facet reflectivity can produce about ~83.8% dynamic single-mode yield (SMY), improved average Q-value, and reduced low-frequency drop (LFD) in the modulation response. By choosing the optimal grating length for the PCG-DFB and applying an asymmetric QWS-DFB, the EMLs can maintain good static- and dynamic performances over a wide range of the linear gain coefficients.