Optical studies of high tilt SiO aligned thin layers of smectic C materials

In thin layers of aligned smectic C materials, the balance between surface and bulk elastic forces within the confine of the chevron layer geometry led to the proposal for a triangular director profile (TDP), and an understanding of the director profile in parallel aligned low tilt cells. We have measured the wavelength dependent extinction angles of high tilt cells fabricated using 5° SiO alignment, and offer a qualitative explanation based on the TDP. We conclude that the differences in the extinction angles at wavelengths around λ = Δd are a useful probe of the SC director profile.