Thermally resilient tm-doped large mode area photonic crystal fiber with symmetry-free cladding

The design of a Tm-doped photonic crystal fiber with 80 μm core diameter and robust single-mode guiding is proposed. State-of-art modal discrimination is obtained through the suppression of the inner cladding C_6v symmetry, which fosters the delocalization of the LP₁₁-like mode. The effects of thermally-induced refractive index change are investigated by means of a computationally-efficient thermal model, and the possibility to obtain wide-band single-mode propagation and effective area exceeding 2500 μm ² under a heat load of over 300 W/m is demonstrated.