In-fiber single-polarization diffraction grating based on radiant tilted fiber grating.

Area of Science:

• Photonics and Optical Engineering
• Fiber Optics
• Diffraction Gratings

Background:

• Tilted Fiber Gratings (TFGs) are widely used in optical fiber sensing and communication.
• Achieving single-polarization operation in fiber gratings is crucial for advanced optical systems.
• Existing methods for polarization control in fiber gratings can be complex or inefficient.

Purpose of the Study:

• To propose and theoretically model an in-fiber single-polarization diffraction grating based on a radiant TFG.
• To investigate the angular dispersion characteristics of the radiant TFG.
• To experimentally validate the performance of the proposed radiant TFG for single-polarization light diffraction.

Main Methods:

• Development of a theoretical model using Fourier optics analysis to describe the angular dispersion of a radiant TFG.
• Numerical characterization of angular dispersion based on parameters like tilt angle, period, and wavelength.
• Experimental fabrication and characterization of UV-inscribed radiant TFGs in single-mode fiber.
• Measurement of diffraction angles and angular dispersion for TFGs with varying tilt angles.

Main Results:

• The theoretical model accurately predicts the angular dispersion of radiant TFGs.
• Numerical simulations show wavelength-dependent diffraction angles influenced by tilt angle and period.
• Experimental results for diffraction angles and angular dispersion closely match simulation predictions.
• The diffracted light exhibits a high degree of linear polarization (>0.99) for tilt angles between 41° and 47°.

Conclusions:

• The proposed radiant tilted fiber grating is an effective in-fiber device for single-polarization light diffraction.
• The device demonstrates controllable angular dispersion and high polarization purity.
• This technology holds potential for applications requiring polarization-selective optical components in fiber systems.