Benefits of Photonic Bandgap Fibers for the Thermal Stabilization of Optoelectronic Oscillators

This work reports on the analysis of optoelectronic oscillators (OEO) realized with various kinds of microstructured optical fibers (MOF) as delay lines. More precisely, the thermal dependence of the group delay is measured through the analysis of the thermal variation of the frequency of the OEO and compared with a theoretical model that includes the effect of temperature on refractive index, strains, and deformation. It is shown that, whereas the presence of air in air/silica fibers guiding via modified total internal reflection (M-TIR) has only little interest, it allows a net decrease of the thermal variation of the group delay in the case of hollow core photonic bandgap (HC-PBG) fiber. In addition to the effect of material, we show that this decrease is related to the PBG mechanism itself, which is a property also exploited in a solid-core photonic bandgap (SC-PBG) fiber.