The optical cavity features a plano-concave design, with the concave mirror reflection of 99% , and the planar mirror, coated with a high-reflectivity (HR) coating (R = 95%, 420-650 nm), as well as the chiral PTPO thin film. The cylindrical lens focuses the pump beam into a narrow line with a beam size about 0.1 mm x 10 mm to maximize the overlap between the pump and dye laser cavity resonant modes. We used a 0.22 g/L solution of Stilbene 420 dye in an ethanol-water mixture (2:1 ratio). The dye cell is circulated to mitigate heat accumulation, where the dye solution is pumped through a cuvette (1×1×10 mm 3 ) with polished sides.