Surface and Interface Engineering in Integrated Photonic Sensors: Performance Trade-Offs, Stability, and Benchmarking

Area of Science:

• Photonics
• Materials Science
• Surface Chemistry

Background:

• Surface and interface engineering critically impacts integrated photonic sensor performance and reliability.
• As device architectures advance, the nanoscale interface becomes the primary determinant of sensitivity, noise, and stability.
• Conventional optimization strategies are reaching fundamental limits, shifting focus to interface-level control.

Purpose of the Study:

• To critically review recent advances in surface and interface engineering for integrated photonic sensing platforms.
• To analyze how functional layers, nanomaterials, and hybrid interfaces affect light-matter interactions and sensor performance.
• To evaluate benchmarking methodologies and identify challenges for translating lab-scale sensors to robust technologies.

Main Methods:

• Review of recent literature on surface and interface engineering in photonic sensing.
• Analysis of strategies applied to waveguide, interferometric, and resonant photonic architectures.
• Examination of performance metrics, trade-offs, and stability challenges.

Main Results:

• Functional layers and nanomaterials can enhance light-matter interactions but may introduce optical loss and spectral distortion.
• Conventional metrics like bulk sensitivity and limit of detection have limitations; normalized figures of merit are essential.
• Significant trade-offs exist between enhanced surface interaction, optical degradation, and temporal stability.

Conclusions:

• Interface engineering is key for advancing integrated photonic sensors, but challenges in reproducibility and long-term stability remain.
• Normalized figures of merit are crucial for accurate performance comparison across diverse platforms.
• Further research is needed to develop design principles for robust, scalable surface-engineered photonic sensors.