Measuring on-chip waveguide losses using a single, two-point coupled microring resonator.

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Accurate measurement of on-chip waveguide propagation loss is crucial for integrated photonic devices.
• Existing methods often require complex setups or are sensitive to alignment errors.

Purpose of the Study:

• To develop a simplified and robust method for measuring waveguide propagation losses on-chip.
• To enable accurate loss characterization without expensive phase measurement equipment.

Main Methods:

• Utilized a single microring resonator with a tunable coupler.
• Varied power coupling to the microring and measured through-port transmission.
• Separated waveguide propagation loss from coupling effects.

Main Results:

• Achieved separation of waveguide propagation loss and coupling effects.
• Demonstrated tolerance to fiber-chip coupling and alignment errors.
• Measured propagation losses of 3.1-1.3 dB/cm for silicon-on-insulator rib waveguides (400-600 nm core width).

Conclusions:

• The proposed method provides a compact and accurate solution for on-chip waveguide loss measurement.
• This technique simplifies loss characterization, making it accessible for various integrated photonic applications.
• The method is robust and does not necessitate specialized or costly instrumentation.