Low-loss cascaded mach-zehnder multiplexer integrated 25-Gbits × 4-Lane EADFB laser array for future CFP4 100 GbE transmitter

Takeshi Fujisawa, Shigeru Kanazawa, Yuta Ueda, Wataru Kobayashi, Kiyoto Takahata, Akira Ohki, Toshio Ito, Masaki Kohtoku, Hiroyuki Ishii

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


A 4 × 25-Gb/s electroabsorption modulator integrated with a distributed feedback (DFB) laser (EADFB laser) array monolithically integrated with a low-loss optical multiplexer (MUX) is developed for 100 GbE transmitters for the first time. A cascaded Mach-Zehnder (MZ) filter, which has no intrinsic loss, is used as the MUX. The design and fabrication of the MZ-MUX for 100 GbE are thoroughly described. The measured loss of fabricated MZ-MUX is 2-3 dB, which is improved by 4 dB compared with that of the conventional 1 × 4 multimode interference MUX. The MZ-MUX is monolithically integrated with a four-EADFB-laser array and the output power of the chip is increased by 3 dB compared with that of a conventional 4 × 25-Gb/s monolithically integrated chip. With the folded layout, the size of the chip is similar to that of the conventional chip. The fabricated chip is packaged into a very compact transmitter optical subassembly (TOSA). The system requirements are satisfied with semi-cooled operation, and very clear eye openings are obtained after 10-km single-mode-fiber transmission. The adjustment of filter spectra by current injection is also shown, and fine tuning is possible with very low injection current.

Original languageEnglish
Article number2284242
Pages (from-to)1001-1007
Number of pages7
JournalIEEE Journal of Quantum Electronics
Issue number12
Publication statusPublished - 2013
Externally publishedYes


  • 100 GbE
  • Electroabsorption modulator
  • Low-loss multiplexer
  • Mach-Zehnder filter
  • Monolithic integration

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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