where L is the cavity length, δ is other losses (such as scattering, additional absorption, etc.), showing excellent agreement. The fitted pump rate of 6.0×10 23 /s corresponds to a pump energy of 1.6 mJ, which closely matches the measured value. In the simulation, the DOCP is derived assuming a perfect DOP of 1. For the experimental data, since the DOP is not ideal, the DOCP is normalized by the DOP for direct comparison with the simulation. Near the lasing threshold (pump energy around 1.2 mJ), this differential loss is significant, but as the pump energy continues to increase, the gain surpasses the influence of the differential loss. Consequently, the asymmetry in loss becomes less significant, causing the DOCP to decrease from its peak at higher pump energies. When DOCP is normalized by the total pulse energy and DOP (right panel), an exponential decay is observed, revealing a gradual decrease in DOCP as pump energy increases. This suggests that the effect of differential losses between RCP and LCP photons, caused by the nonreciprocal PTPO thin film, becomes less significant at higher pump rates where gain exceeds differential absorption. These results highlight that the final DOCP is primarily influenced by two factors: the total number of linearly polarized photons, mainly originating from laser-induced stimulated emission in the achiral dye gain medium pumped by a linearly polarized laser, and the disparity in photon populations between RCP and LCP light. This DOCP value is consistent with the expectation based on the results of the sum of single-pass front and back g abs (∼-0.17 at wavelength of 420 nm) and the cavity enhancement factor (Finesse/π ∼6).