Resonance optical activity in multihelicoidal optical fibers.

Area of Science:

• Optics and Photonics
• Fiber Optics
• Electromagnetism

Background:

• Optical fibers with multihelical refractive index profiles exhibit unique light propagation characteristics.
• Resonance wavelengths are critical points where light conversion phenomena occur, such as Gaussian beam to optical vortex transformation.

Purpose of the Study:

• To investigate the effect of optical activity (OA) in multihelical optical fibers near resonance wavelengths.
• To analyze the polarization vector rotation of a Gaussian beam within such fibers.
• To understand the relationship between OA and the propagation constants of optical vortices.

Main Methods:

• Theoretical study of light propagation in multihelical optical fibers.
• Analysis of polarization dynamics of a Gaussian beam near resonance.
• Calculation of propagation constants for left- and right-circularly polarized optical vortices.

Main Results:

• Demonstrated that the polarization vector of an incident Gaussian beam rotates within the fiber at the resonance wavelength.
• Showed that the average rotation rate is proportional to the difference in propagation constants of circularly polarized optical vortices with identical topological charge.
• Identified that for specific fiber lengths, optical activity can achieve anomalously high values, significantly exceeding the average.

Conclusions:

• Multihelical optical fibers exhibit significant optical activity near resonance wavelengths, enabling controlled polarization rotation.
• The observed polarization rotation is directly linked to the fiber's modal properties, specifically the propagation constants of optical vortices.
• The potential for anomalously high optical activity opens possibilities for novel fiber-based optical devices and applications.