The effects of air-holes on temperature and temperature gradient of solid-core photonic crystal fiber lasers

Abstract

We report on the effects of air-holes on temperature and temperature gradient of solid-core photonic crystal fiber lasers (PCFLs) using finite element method. The temperature distribution and the temperature gradient over PCFL cross section were simulated as function of induced heat. Our simulations were devoted to three kinds of PCFLs with various d/Λ ratios where large-mode-area solid-core PCFLs with air-holes triangular lattice as cladding and polymer coatings were considered. For thermal modeling, all cooling mechanisms such as convection and radiation have been taken into account. Also, the temperature dependence of silica thermal conductivity has been considered. The results show that variation of d/Λ ratio has no noticeable effects on the core temperature, whereas the presence of air-holes in the cladding can significantly increase the temperature gradients. Moreover, the importance of heat dissipation by radiation, which is usually neglected in the literature were shown. It is shown that this effect is a robust cooling mechanism for fiber lasers.