Bloch-mode extraction from near-field data in periodic waveguides

Area of Science:

• Photonics
• Solid-state physics
• Wave phenomena

Background:

• Bloch modes are crucial for understanding wave propagation in periodic structures like photonic crystals.
• Characterizing both propagating and evanescent Bloch modes spatially is essential for designing advanced optical devices.
• Existing methods for Bloch mode characterization can be complex and require multiple measurements.

Purpose of the Study:

• To develop a novel, single-measurement technique for extracting spatial profiles of Bloch modes.
• To extend high-resolution spectral methods to spatial data for analyzing Bloch modes.
• To demonstrate the method's applicability and robustness in a realistic photonic crystal waveguide scenario.

Main Methods:

• A systematic extraction procedure was developed by adapting high-resolution spectral methods for spatial data.
• The method incorporates the symmetry properties of Bloch modes across all spatial locations.
• The technique relies on a single measurement of the electric field at a specific optical wavelength.

Main Results:

• Successfully extracted spatial profiles for both propagating and evanescent Bloch modes from a single measurement.
• The developed procedure accurately characterizes Bloch modes in a photonic crystal waveguide interface.
• The method demonstrated robustness and reliability even when subjected to noise.

Conclusions:

• A simplified and effective method for Bloch mode spatial profile extraction has been established.
• This technique offers a significant advancement for the characterization of optical properties in periodic structures.
• The findings pave the way for improved design and analysis of photonic devices.