Sub-50-pm displacement sensing via phase-matched metasurface-prism configuration

Area of Science:

• Optics and Photonics
• Metrology
• Materials Science

Background:

• Accurate transverse displacement measurement is crucial for ultraprecision metrology and understanding microscopic interactions.
• Existing methods often face challenges with optical alignment and environmental interference.
• Picometer-scale resolution is a key requirement for advanced scientific and industrial applications.

Purpose of the Study:

• To demonstrate a high-precision transverse displacement sensor.
• To leverage Pancharatnam-Berry (PB) metasurfaces and a trapezoidal prism for simplified optical alignment.
• To achieve robust signal extraction and overcome limitations of conventional methods.

Main Methods:

• Utilizing a phase-matched PB metasurface integrated with a trapezoidal prism.
• Employing the photonic spin Hall effect for signal extraction.
• Using a near-infrared source (1550 nm) and differential amplification to minimize noise and interference.

Main Results:

• Achieved a displacement resolution of 46.18 pm under quasi-static conditions (0.2-100 Hz).
• Demonstrated a resolution of 124.86 pm across the full operational bandwidth (0.2-1.25 MHz).
• Outperformed conventional polarization-encoded schemes in sensitivity and practicality.

Conclusions:

• Presented a novel metasurface-enhanced metrology strategy using geometric-phase-engineered photonic architectures.
• The sensor offers enhanced sensitivity and practicality for picometer-scale transverse displacement measurement.
• Potential applications span semiconductor lithography, quantum optomechanics, and other fields requiring ultraprecision measurements.