224-Gbit/s 4-PAM operation of a high-modulation-bandwidth high-output-power Hi-FIT AXEL transmitter

Area of Science:

• Optoelectronics
• Integrated Photonics
• High-Speed Communication

Background:

• Advancements in optical communication require higher data rates and improved transmitter performance.
• Existing technologies face limitations in modulation bandwidth and output power.

Purpose of the Study:

• To fabricate and characterize a novel optical transmitter for 200-Gbit/s/λ applications.
• To enhance modulation bandwidth and optical output power using integrated design techniques.

Main Methods:

• Fabrication of an optical transmitter integrating the flip-chip interconnection technique (Hi-FIT) and an assisted extended reach electroadsorption modulator integrated distributed feedback (EADFB) laser (AXEL).
• Utilizing wire-free interconnection and peaking control for increased modulation bandwidth.
• Incorporating a semiconductor optical amplifier (SOA) within the AXEL for enhanced output power.

Main Results:

• The fabricated Hi-FIT AXEL transmitter achieved a 3-dB bandwidth exceeding 66 GHz.
• Clear 224-Gbit/s 4-level pulse amplitude modulation (4-PAM) eye diagrams were obtained.
• A chip-output optical modulation amplitude (OMA) of over +7.9 dBm was achieved at specific DFB laser and SOA currents.

Conclusions:

• The integrated Hi-FIT AXEL transmitter successfully meets the demands for high-frequency and high-speed optical communication.
• The combination of Hi-FIT and AXEL offers a viable solution for achieving high modulation bandwidth and output power.
• This technology enables advanced optical transmission systems for future high-capacity networks.