Rayleigh anomaly induced phase gradients in finite nanoparticle chains

Area of Science:

• Plasmonics and Nanophotonics
• Optical Metamaterials
• Diffraction Physics

Background:

• Collective optical interactions in infinite nanoparticle arrays are well-studied.
• Analysis of finite nanoparticle arrays and their unique optical phenomena remains less explored.
• Understanding finite array behavior is crucial for advanced optical device development.

Purpose of the Study:

• To investigate the collective optical interactions in finite nanoparticle chains.
• To demonstrate the occurrence of phase gradients and their effect on diffraction patterns.
• To explore the role of the Rayleigh anomaly in finite nanoparticle arrays.

Main Methods:

• Theoretical modeling using the discrete dipole approximation.
• Numerical simulations to validate theoretical predictions.
• Development of a novel analytical approach for calculating particle dipole moments.

Main Results:

• Finite nanoparticle chains support phase gradients that shift diffraction patterns compared to infinite arrays.
• This phenomenon is observed in a specific spectral range around the Rayleigh anomaly condition.
• The Rayleigh anomaly, typically associated with intensity changes, induces angular anomalies in finite arrays.

Conclusions:

• Collective optical interactions in finite nanoparticle arrays exhibit unique phase gradient phenomena.
• The Rayleigh anomaly plays a dual role, influencing both intensity and angular characteristics in finite arrays.
• These findings have potential applications in LIDAR systems and beam shaping technologies.