Optical properties of poly (oxyisophthaloyloxy (2-methoxy-p-phenylene) methylid-ine (2-oxo-1, 3-cyclohexanediylidene) methylidene (2-methoxy-p-phenylene)) I and poly (oxysebacoyloxy (2-methoxy-p-phenylene) methylidene (2-oxo-1, 3-cyclohex-andeiylidene) methylidene (3-methoxy-p-phenylene)) II polymer films were studied. Transmission and absorption measurements were carried out in the energy range 1.9 to 3.2 eV at 300 K. Absorption coefficient data were analysed and interpreted in terms of the Tauc model (alpha h (cross) w) 1 2/= square root B (h (cross) wE g opt). Analysis of experimental results shows that the absorption characteristics give a good fit to the Tauc model. This indicates that both polymers (I and II) have an indirect band gap. The values of the optical gap E g opt and the slope of Tauc plots square root B were determined. The study shows that the indirect allowed optical transitions are …