0.77-V drive voltage electro-optic modulator with bandwidth exceeding 67 GHz

Area of Science:

• Optoelectronics
• Materials Science
• Electrical Engineering

Background:

• High-performance electro-optic modulators are crucial for advancing optical communication systems.
• Existing modulators often face trade-offs between drive voltage, bandwidth, and fabrication complexity.
• Minimizing ohmic losses and achieving velocity matching are key challenges in modulator design.

Purpose of the Study:

• To develop an electro-optic modulator with a significantly reduced drive voltage (V(π)) and enhanced bandwidth.
• To explore novel fabrication techniques and device structures for improved modulator performance.
• To address key loss mechanisms and achieve efficient velocity matching in traveling-wave modulators.

Main Methods:

• Fabrication of a compound semiconductor device utilizing substrate removal technology.
• Integration of a p-i-n diode within an optical waveguide with electrodes on both sides.
• Incorporation of a multiple quantum well (MQW) structure in the waveguide core.
• Design as a traveling-wave device employing the loaded line approach for velocity matching.

Main Results:

• Achieved a record low drive voltage (V(π)) of 0.77 V.
• Demonstrated a bandwidth exceeding 67 GHz.
• Significantly reduced ohmic losses through optimized electrode placement.
• Maintained low propagation and coupling losses via waveguide design and detuning.

Conclusions:

• The developed electro-optic modulator offers the lowest V(π) and widest bandwidth to date.
• Substrate removal technology and optimized device architecture are key to achieving superior performance.
• This device represents a significant advancement for high-speed optical communication applications.