Earlier research has shown that these chiral films can enhance CD effects in passive optical cavities, significantly influencing the balance of cavity transmission between RCP Assuming the initial light is linearly polarized (comprising equal intensities of RCP and LCP light), it encounters the 2D chiral film where the CD is negative, causing greater absorption loss for RCP compared to LCP. In step 2, when this CP light reflects off a standard mirror at normal incidence, the handedness reverses-RCP becomes LCP, and vice versa. Upon re-entering the chiral film from the opposite side in step 3, where the CD is positive, LCP now experiences more absorption loss than RCP. In step 4, the mirror again reverses the handedness. Thus, within each round trip, the chiral film's directional dependence causes alternating asymmetrical losses for RCP and LCP, shifting the balance between them and creating a cumulative asymmetry in cavity losses. The pump source for the dye laser is a third harmonic generation from a pulsed optical parametric oscillator (OPO) laser (Amplitude-Laser, Surelite Ex), driven by a pulsed Nd:YAG laser. The pump laser operates at 355 nm with a pulse width of 3-5 ns, a repetition rate of 10 Hz, and a polarization extinction ratio exceeding 10 -3 . A half-wave plate (HWP), positioned after the attenuator, is used to control the polarization direction of the pump laser, enabling precise tuning between transverse electric (TE) and transverse magnetic (TM) polarization modes during dye excitation.