Single shot polarimetric characterization of the polymer based flexible polyethylene terephthalate substrate

Abstract

AbstractConducting polyethylene terephthalate (PET) substrates used for the flexible electronics and photonics are birefringent in nature. Birefringence of the PET substrate increases with the external applied stress. In this paper, we have studied the state of the polarization of the light transmitted through the flexible PET substrate. Polarimetric characterization of flexible substrate was done for red and yellow wavelengths of light. Single shot three beams interference was recorded by the polarizing Mach–Zehnder interferometer. Interferograms were recorded without bending and different external bending applied to the substrate which increases the stress. The recorded interferograms was analyzed by the Fourier transform fringe (FTF) analysis method. The single shot interferograms have the information of the amplitude and phase of orthogonally polarized field components. Stokes parameters were calculated from orthogonal polarization component extracted from the single shot interferograms analyzed by FTF. Calculated Stokes parameters were plotted on the Poincare sphere to see the change in the state of polarization (SOP) of the light transmitted through these substrates. The change in the SOP of the transmitted light was observed without and with the external stress applied to the PET substrate due to its birefringence characteristic.