Thermally tuned parametric gain in photonic crystal fiber-based amplifiers Hassan Pakarzadeh, Fereshteh Hasanpouri, Shahrzad Hosseinabadi and Vahid Sharif Eur. Phys. J. Plus, 136 3 (2021) 298 Published online: 07 March 2021 DOI: 10.1140/epjp/s13360-021-01293-3