Fully reconfigurable compact RF photonic filters using high-Q silicon microdisk resonators

Area of Science:

• Photonics
• Electrical Engineering
• Materials Science

Background:

• Radio frequency (RF) photonic filters are crucial for modern communication systems.
• Existing filters often face limitations in tunability, size, and power consumption.
• Silicon-on-insulator (SOI) platforms offer advantages for integrated photonic devices.

Purpose of the Study:

• To design and demonstrate a fully reconfigurable fourth-order RF photonic filter on an SOI platform.
• To achieve a compact filter with tunable bandwidth and high optical rejection.
• To explore the potential for cascading filter units for enhanced performance.

Main Methods:

• Utilized a unit-cell based architecture for filter design.
• Incorporated high-Q resonator-based components to reduce size, weight, and power (SWaP).
• Employed thermal reconfiguration for low insertion loss and scalability.

Main Results:

• Achieved a tunable 3-dB bandwidth from 0.9-5 GHz.
• Demonstrated over 38 dB optical out-of-band rejection.
• Realized a Free Spectral Range (FSR) up to 650 GHz with a compact footprint (0.25 mm^2).
• Tuned center wavelength over a wide range with low power consumption (10 mW/nm).

Conclusions:

• The demonstrated RF photonic filter meets key specifications for reconfigurability, performance, and size.
• The unit-cell approach and thermal tuning enable scalable and low-loss filter designs.
• This technology is suitable for applications like RF photonic front-ends and high-speed optical analog-to-digital conversion.