Self-biasing of carrier depletion based silicon microring modulators

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Devices

Background:

• Silicon microring modulators (MRMs) are crucial components in optical communication systems.
• Traditional MRMs require external reverse bias for optimal operation, complicating driver circuitry.
• Carrier depletion is a common mechanism for modulating light in silicon MRMs.

Purpose of the Study:

• To investigate and demonstrate the self-biasing effect in carrier-depletion-based silicon MRMs.
• To show that MRMs can achieve open eye diagrams for NRZ OOK modulation without external bias.
• To evaluate the performance of self-biasing in different MRM configurations and operating conditions.

Main Methods:

• Fabrication of silicon MRMs with integrated electrical passive components on the same chip.
• Experimental characterization of single-ended and differential drive MRM configurations.
• Testing under various conditions including modulation speeds, voltage swing, optical power, and wavelength.

Main Results:

• Open eye diagrams achieved for NRZ OOK modulation at speeds up to 36 Gbit/s (single-ended) and 60 Gbit/s (differential).
• Self-biasing effect demonstrated to be robust across a wide range of operating parameters.
• Successful operation in both terminated and non-terminated, single-ended and differential MRM configurations.

Conclusions:

• The self-biasing effect in silicon MRMs eliminates the need for external DC biases.
• This simplifies driver-modulator interfaces and reduces the complexity of photonic integrated circuits.
• The findings pave the way for more compact and power-efficient optical modulators.