Fig. 4
From: Bose–Einstein condensation of photons in an erbium–ytterbium co-doped fiber cavity
Threshold power Pc dependence on temperature T. It is obtained by the intersection with the P-axis of the linear parts fit in Fig. 3. The graph gives an almost linear dependence in accordance with the theoretical result of P = aT. The slope in the experiment is (0.031 ± 0.003) μW/K, close to the theoretical value a ≈ 0.034 μW/K without any adjustable parameter. The error bars result from uncertainty in the temperature measurements of the fiber core, as well as s.d. in the fitting of the linear parts of the graphs in Fig. 3
