Low loss, high-speed single-mode half-disk resonator.

Area of Science:

• Photonics and Nanotechnology
• Integrated Optics

Background:

• Microring resonators are crucial for integrated photonics but often suffer from limited contact size.
• Large electrical or mechanical contacts are desirable for active photonic devices but challenging to implement without compromising resonator performance.

Purpose of the Study:

• To introduce and analyze a novel single-mode half-disk resonator.
• To demonstrate a systematic design methodology for this new resonator type.
• To showcase the benefits of large contacts for active photonic devices.

Main Methods:

• Theoretical design and simulation of the half-disk resonator.
• Experimental fabrication and characterization of the resonator.
• Analysis of contact resistance in a vertical PN junction modulator utilizing the resonator.

Main Results:

• The half-disk resonator maintains single-mode operation despite large contact areas.
• Simulated internal Q-factor reached 2.4×10⁵ for a 3 μm radius resonator.
• Experimentally measured loaded Q-factor of ~9000, comparable to larger microrings.
• Contact resistance in a PN junction modulator reduced by nearly an order of magnitude.

Conclusions:

• The single-mode half-disk resonator offers a viable solution for integrating large contacts in photonic devices.
• This design significantly enhances the performance of active devices, enabling faster modulation speeds.
• The demonstrated design method provides a pathway for optimizing such resonators for various applications.