Fig. 2: Spectrum of the cavity output.
From: Non-stationary statistics and formation jitter in transient photon condensation

The figure shows spectra above and below the condensation threshold at the critical excitation energy Pth. The spectral peak is located at the fundamental mode (ground state) of the cavity, or cavity cutoff, at approximately 602 nm. The inset depicts the total cavity output (dots) and comparison with the single-mode mean-field model, with (full line) and without (dashed line) the contribution from the spontaneous emission background. The arrow indicates the threshold point.