Polymer optical microstructured fiber with birefringence induced by stress-applying elements.

Area of Science:

• Materials Science
• Optical Engineering
• Polymer Science

Background:

• Microstructured polymer optical fibers (MPOFs) offer unique light manipulation properties.
• Birefringent fibers are crucial for polarization-dependent applications.
• PMMA and polystyrene are common polymers used in fiber fabrication.

Purpose of the Study:

• To fabricate a novel birefringent microstructured PMMA fiber.
• To characterize its optical properties, including birefringence, wavelength dependence, and loss.
• To investigate the fiber's response to temperature variations.

Main Methods:

• Fabrication of a microstructured PMMA fiber using a drilling method.
• Incorporation of polystyrene stress-applying elements within the cladding.
• Optical characterization of birefringence, wavelength dependence (0.6-1 μm), polarization crosstalk, and fiber loss.
• Thermal characterization of birefringence changes from 20°C to 60°C.

Main Results:

• Achieved high birefringence of approximately 4×10⁻⁵, with weak wavelength dependence.
• Demonstrated low polarization crosstalk (< -20 dB over 1 m) and fiber loss (~8 dB/m at 0.83 μm).
• Observed negative temperature-induced birefringence change with significant initial hysteresis, which reduced in subsequent cycles.

Conclusions:

• The fabricated PMMA fiber exhibits promising properties for polarization-sensitive applications.
• The fiber shows good stability over the investigated spectral range and temperature variations.
• The observed thermal hysteresis warrants further investigation for long-term applications.