Real-time phase error compensation in phase sensitive scanning near-field optical microscopy

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Accurate phase measurements are crucial for understanding the optical properties of surface plasmon polariton (SPP) nanostructures.
• Existing phase-sensitive scanning near-field optical microscopy (SNOM) methods often require post-processing or prior knowledge of environmental conditions, limiting real-time analysis.

Purpose of the Study:

• To propose and demonstrate a real-time phase error compensation method for phase-sensitive SNOM.
• To improve the accuracy and reliability of SPP nanostructure optical property measurements.

Main Methods:

• Development of a real-time phase error compensation system for SNOM.
• Utilizing a common optical path configuration and common-mode rejection (CMR) principle.
• Experimental validation using a SPP focusing device.

Main Results:

• The proposed method achieves real-time phase error compensation, relying primarily on optical devices.
• No post-processing or prior environmental knowledge is required for compensation.
• Experimental results show significant improvements in phase accuracy and drift handling compared to previous SNOM techniques.
• Measured distributions align well with finite-difference time-domain (FDTD) simulations.

Conclusions:

• The developed real-time phase error compensation method offers a robust solution for accurate SPP nanostructure characterization.
• This advancement facilitates more reliable investigations into the optical properties of nanostructures.
• The method's effectiveness is experimentally verified, demonstrating its practical applicability.