Polarization-maintaining near-field optical probes.

Area of Science:

• Photonics
• Optics
• Nanotechnology

Background:

• Tapered optical fibers are crucial for near-field optical applications.
• Controlling polarization in near-field light is essential for advanced optical techniques.

Purpose of the Study:

• To demonstrate a novel tapered optical fiber probe capable of generating a well-defined, polarized near-field.
• To design a probe that maintains light polarization irrespective of the input polarization state.

Main Methods:

• Modification of the taper cone of optical fibers with a Short-cut Double C-shaped probe design.
• Full metal coating near the tapered end of the fiber.
• Finite-difference time domain (FDTD) simulations to predict near-field properties.
• Experimental testing and polar diagram measurements of a manufactured probe prototype.

Main Results:

• The novel probe design functions as an electric dipole emitter.
• Simulations predicted linearly polarized near-field light output.
• Experimental measurements confirmed polarization maintenance in the near-field.

Conclusions:

• The developed tapered optical fiber probe reliably produces a linearly polarized near-field.
• The probe geometry dictates the spatial orientation of the electric dipole, ensuring polarization stability.
• This technology offers a robust solution for applications requiring controlled near-field polarization.