Nanorods with multidimensional optical information beyond the diffraction limit.

Area of Science:

• Nanotechnology
• Materials Science
• Optics

Background:

• Integrating multiple functionalities into nanoscale devices requires precise fabrication of heterogeneous nanostructures.
• The diffraction limit (~200 nm) hinders control and characterization of optical uniformity and diversity in these nanostructures.

Purpose of the Study:

• To develop a method for fabricating heterogeneous nanorods with distinct optical properties.
• To demonstrate super-resolution characterization of individual sections within these nanorods.
• To showcase the potential of these nanorods as polychromatic light sources.

Main Methods:

• Utilizing a highly controlled epitaxial growth approach to create heterogeneous nanorods.
• Employing donut-shaped illumination to probe unique nonlinear optical responses of each nanorod section.
• Characterizing tunable upconversion emissions in four optical dimensions: color, lifetime, excitation wavelength, and power dependency.

Main Results:

• Successfully fabricated heterogeneous nanorods where each section exhibits unique nonlinear optical responses.
• Achieved super-resolution discernment of individual optically active sections within the nanorods.
• Demonstrated tunable upconversion emissions across color, lifetime, excitation wavelength, and power dependency.
• Showcased a 210 nm nanorod as a compact polychromatic light source for RGB emission generation.

Conclusions:

• This work establishes precise control over sub-diffraction-limit optical diversities in single heterogeneous nanoparticles.
• The developed fabrication approach enables the creation of advanced nanoscale devices with integrated functionalities.
• Heterogeneous nanorods offer a promising platform for novel optical applications, including miniature light sources.