Sagnac loop interferometer based on polarization maintaining photonic crystal fiber with reduced temperature...

Area of Science:

• Optics and Photonics
• Materials Science
• Fiber Optic Sensing

Background:

• Sagnac loop interferometers are sensitive to environmental changes, particularly temperature.
• Photonic crystal fibers offer unique properties for optical sensing applications.
• Understanding temperature dependence is critical for the stability and accuracy of fiber optic sensors.

Purpose of the Study:

• To construct and analyze a Sagnac loop interferometer utilizing polarization-maintaining photonic crystal fiber.
• To investigate and quantify the temperature dependence of the Sagnac loop's filter function.
• To determine the temperature-dependent birefringence coefficient of the novel fiber optic setup.

Main Methods:

• Fabrication of a Sagnac loop interferometer with polarization-maintaining photonic crystal fiber.
• Measurement of the Sagnac loop's filter function across a temperature range exceeding 200 degrees C.
• Comparative analysis with a standard Sagnac loop interferometer under identical experimental conditions.

Main Results:

• An unambiguous temperature-dependent birefringence coefficient (dn/dT) of 2.0 x 10^-9 /K was deduced for the photonic crystal fiber Sagnac loop.
• The maximum peak shift in the filter function was less than 10% of the filter period over the tested temperature range.
• A standard Sagnac loop exhibited a significantly higher dn/dT of 7.0 x 10^-8 /K.

Conclusions:

• Polarization-maintaining photonic crystal fiber offers superior thermal stability for Sagnac loop interferometers.
• The developed interferometer demonstrates a greatly reduced temperature sensitivity compared to conventional designs.
• This advancement is promising for high-precision fiber optic sensing in variable temperature environments.