Subwavelength resolution in a two-dimensional photonic-crystal-based superlens

Area of Science:

• Photonics
• Metamaterials
• Electromagnetism

Background:

• Negative refraction enables unprecedented control over light propagation.
• Photonic crystals offer a platform for designing novel electromagnetic properties.
• Superlensing requires materials with refractive indices near -1.

Purpose of the Study:

• To experimentally and theoretically demonstrate single-beam negative refraction and superlensing.
• To investigate the performance of a two-dimensional photonic crystal in the microwave regime.
• To achieve subwavelength resolution imaging.

Main Methods:

• Fabrication and characterization of a slab-shaped two-dimensional photonic crystal.
• Measurement of refracted electromagnetic waves to determine refractive index.
• Scanning transmission measurements to analyze spatial power distribution.
• Finite difference time domain (FDTD) simulations for validation.

Main Results:

• Experimental refractive index of -1.94, close to the theoretical -2.06.
• Measured full width at half maximum (FWHM) of focused beam at 0.21 lambda.
• Demonstrated subwavelength resolution imaging of two point sources separated by lambda/3.

Conclusions:

• The two-dimensional photonic crystal effectively exhibits negative refraction and superlensing.
• Experimental results align well with theoretical predictions and FDTD simulations.
• The demonstrated subwavelength resolution highlights the potential of photonic crystals for advanced imaging.