Polarization-Modulated, Goos⁻Hanchen Shift Sensing for Common Mode Drift Suppression

Area of Science:

• Optics
• Sensing Technology
• Surface Physics

Background:

• The Goos-Hanchen (GH) shift is sensitive to surface conditions.
• Conventional GH shift measurements are susceptible to environmental and instrumental noise.
• Bloch surface waves (BSWs) can significantly enhance the GH shift, improving sensitivity.

Purpose of the Study:

• To propose and demonstrate a novel polarization-modulation-based sensing scheme for enhanced Goos-Hanchen (GH) shift detection.
• To leverage the polarization-dependence of BSW-enhanced GH shifts for improved sensing.
• To develop a robust and stable GH shift sensing setup resilient to common mode drifts and noise.

Main Methods:

• Utilized a polarization-modulation technique with a liquid crystal modulator to switch input beam polarization.
• Employed a lock-in amplifier to monitor the alternating positions of the reflected beam for different polarizations.
• Exploited the Bloch surface wave (BSW) enhanced GH shift phenomenon.

Main Results:

• Successfully demonstrated a polarization-modulation-based GH sensing scheme.
• Achieved sensitive retrieval of the GH shift signal by monitoring alternating beam positions.
• Showcased enhanced system stability by suppressing common mode drift and noise compared to conventional methods.

Conclusions:

• The proposed scheme offers a sensitive and robust method for GH shift sensing.
• Polarization modulation effectively enhances the detection of BSW-enhanced GH shifts.
• This technique provides a stable platform for optical sensing applications, mitigating common instabilities.